Commit Graph

791997 Commits

Author SHA1 Message Date
Peter Zijlstra
40b539bf2e UPSTREAM: x86/uaccess, kasan: Fix KASAN vs SMAP
(Upstream commit 57b78a62e7).

KASAN inserts extra code for every LOAD/STORE emitted by te compiler.
Much of this code is simple and safe to run with AC=1, however the
kasan_report() function, called on error, is most certainly not safe
to call with AC=1.

Therefore wrap kasan_report() in user_access_{save,restore}; which for
x86 SMAP, saves/restores EFLAGS and clears AC before calling the real
function.

Also ensure all the functions are without __fentry__ hook. The
function tracer is also not safe.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Bug: 128674696
Change-Id: I636890ae2e0dcb5a54f27942d1b00098bb1a43fe
2019-09-24 17:44:16 -07:00
Peter Zijlstra
6c176c4678 BACKPORT: x86/uaccess: Introduce user_access_{save,restore}()
(Upstream commit e74deb1193).

Introduce common helpers for when we need to safely suspend a
uaccess section; for instance to generate a {KA,UB}SAN report.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Change-Id: I9a1afec5d437689dc9a976b371448c7e81811724
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Bug: 128674696
2019-09-24 17:44:16 -07:00
Qian Cai
0ee9b4391a UPSTREAM: kasan: fix variable 'tag' set but not used warning
(Upstream commit c412a769d2).

set_tag() compiles away when CONFIG_KASAN_SW_TAGS=n, so make
arch_kasan_set_tag() a static inline function to fix warnings below.

  mm/kasan/common.c: In function '__kasan_kmalloc':
  mm/kasan/common.c:475:5: warning: variable 'tag' set but not used [-Wunused-but-set-variable]
    u8 tag;
       ^~~

Link: http://lkml.kernel.org/r/20190307185244.54648-1-cai@lca.pw
Signed-off-by: Qian Cai <cai@lca.pw>
Reviewed-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Bug: 128674696
Change-Id: I46b33353a25e5e3e0ef7b61dba56ae52922a5452
2019-09-24 17:44:15 -07:00
Qian Cai
2a548c12ba UPSTREAM: Revert "x86_64: Increase stack size for KASAN_EXTRA"
(Upstream commit a2863b5341).

This reverts commit a8e911d135.
KASAN_EXTRA was removed via the commit 7771bdbbfd ("kasan: remove use
after scope bugs detection."), so this is no longer needed.

Signed-off-by: Qian Cai <cai@lca.pw>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: bp@alien8.de
Cc: akpm@linux-foundation.org
Cc: aryabinin@virtuozzo.com
Cc: glider@google.com
Cc: dvyukov@google.com
Cc: hpa@zytor.com
Link: https://lkml.kernel.org/r/20190306213806.46139-1-cai@lca.pw
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Bug: 128674696
Change-Id: I81cae91b45c69906239518da0965a139112ccfe2
2019-09-24 17:44:15 -07:00
Andrey Konovalov
6395402ef0 UPSTREAM: kasan: fix coccinelle warnings in kasan_p*_table
(Upstream commit 5c0198b6fb).

kasan_p4d_table(), kasan_pmd_table() and kasan_pud_table() are declared
as returning bool, but return 0 instead of false, which produces a
coccinelle warning.  Fix it.

Link: http://lkml.kernel.org/r/1fa6fadf644859e8a6a8ecce258444b49be8c7ee.1551716733.git.andreyknvl@google.com
Fixes: 0207df4fa1 ("kernel/memremap, kasan: make ZONE_DEVICE with work with KASAN")
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reported-by: kbuild test robot <lkp@intel.com>
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Bug: 128674696
Change-Id: I6db14d97607078ac7b2231d323653815caddadf1
2019-09-24 17:44:15 -07:00
Arnd Bergmann
cdb775fce4 UPSTREAM: kasan: fix kasan_check_read/write definitions
(Upstream commit bcf6f55a0d).

Building little-endian allmodconfig kernels on arm64 started failing
with the generated atomic.h implementation, since we now try to call
kasan helpers from the EFI stub:

  aarch64-linux-gnu-ld: drivers/firmware/efi/libstub/arm-stub.stub.o: in function `atomic_set':
  include/generated/atomic-instrumented.h:44: undefined reference to `__efistub_kasan_check_write'

I suspect that we get similar problems in other files that explicitly
disable KASAN for some reason but call atomic_t based helper functions.

We can fix this by checking the predefined __SANITIZE_ADDRESS__ macro
that the compiler sets instead of checking CONFIG_KASAN, but this in
turn requires a small hack in mm/kasan/common.c so we do see the extern
declaration there instead of the inline function.

Link: http://lkml.kernel.org/r/20181211133453.2835077-1-arnd@arndb.de
Fixes: b1864b828644 ("locking/atomics: build atomic headers as required")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reported-by: Anders Roxell <anders.roxell@linaro.org>
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>,
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Bug: 128674696
Change-Id: Ib6836f63fc9dfe594cd8ce4e99f2ad4489c98a53
2019-09-24 17:44:15 -07:00
Andrey Ryabinin
f46851e627 BACKPORT: kasan: remove use after scope bugs detection.
(Upstream commit 7771bdbbfd).

Use after scope bugs detector seems to be almost entirely useless for
the linux kernel.  It exists over two years, but I've seen only one
valid bug so far [1].  And the bug was fixed before it has been
reported.  There were some other use-after-scope reports, but they were
false-positives due to different reasons like incompatibility with
structleak plugin.

This feature significantly increases stack usage, especially with GCC <
9 version, and causes a 32K stack overflow.  It probably adds
performance penalty too.

Given all that, let's remove use-after-scope detector entirely.

While preparing this patch I've noticed that we mistakenly enable
use-after-scope detection for clang compiler regardless of
CONFIG_KASAN_EXTRA setting.  This is also fixed now.

[1] http://lkml.kernel.org/r/<20171129052106.rhgbjhhis53hkgfn@wfg-t540p.sh.intel.com>

Link: http://lkml.kernel.org/r/20190111185842.13978-1-aryabinin@virtuozzo.com
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Acked-by: Will Deacon <will.deacon@arm.com>		[arm64]
Cc: Qian Cai <cai@lca.pw>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Change-Id: I00d869a5e287e3e198950b78ad17bd6ff6a51595
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Bug: 128674696
2019-09-24 17:44:15 -07:00
Arnd Bergmann
b1932f7fee BACKPORT: kasan: turn off asan-stack for clang-8 and earlier
(Upstream commit 6baec880d7).

Building an arm64 allmodconfig kernel with clang results in over 140
warnings about overly large stack frames, the worst ones being:

  drivers/gpu/drm/panel/panel-sitronix-st7789v.c:196:12: error: stack frame size of 20224 bytes in function 'st7789v_prepare'
  drivers/video/fbdev/omap2/omapfb/displays/panel-tpo-td028ttec1.c:196:12: error: stack frame size of 13120 bytes in function 'td028ttec1_panel_enable'
  drivers/usb/host/max3421-hcd.c:1395:1: error: stack frame size of 10048 bytes in function 'max3421_spi_thread'
  drivers/net/wan/slic_ds26522.c:209:12: error: stack frame size of 9664 bytes in function 'slic_ds26522_probe'
  drivers/crypto/ccp/ccp-ops.c:2434:5: error: stack frame size of 8832 bytes in function 'ccp_run_cmd'
  drivers/media/dvb-frontends/stv0367.c:1005:12: error: stack frame size of 7840 bytes in function 'stv0367ter_algo'

None of these happen with gcc today, and almost all of these are the
result of a single known issue in llvm.  Hopefully it will eventually
get fixed with the clang-9 release.

In the meantime, the best idea I have is to turn off asan-stack for
clang-8 and earlier, so we can produce a kernel that is safe to run.

I have posted three patches that address the frame overflow warnings
that are not addressed by turning off asan-stack, so in combination with
this change, we get much closer to a clean allmodconfig build, which in
turn is necessary to do meaningful build regression testing.

It is still possible to turn on the CONFIG_ASAN_STACK option on all
versions of clang, and it's always enabled for gcc, but when
CONFIG_COMPILE_TEST is set, the option remains invisible, so
allmodconfig and randconfig builds (which are normally done with a
forced CONFIG_COMPILE_TEST) will still result in a mostly clean build.

Link: http://lkml.kernel.org/r/20190222222950.3997333-1-arnd@arndb.de
Link: https://bugs.llvm.org/show_bug.cgi?id=38809
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Qian Cai <cai@lca.pw>
Reviewed-by: Mark Brown <broonie@kernel.org>
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Kostya Serebryany <kcc@google.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Change-Id: Ieefb7b14a9a4c36054e0a6d39f018d39ba78313d
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Bug: 128674696
2019-09-24 17:44:15 -07:00
Qian Cai
e50674c599 UPSTREAM: slub: fix a crash with SLUB_DEBUG + KASAN_SW_TAGS
(Upstream commit 6373dca16c).

In process_slab(), "p = get_freepointer()" could return a tagged
pointer, but "addr = page_address()" always return a native pointer.  As
the result, slab_index() is messed up here,

    return (p - addr) / s->size;

All other callers of slab_index() have the same situation where "addr"
is from page_address(), so just need to untag "p".

    # cat /sys/kernel/slab/hugetlbfs_inode_cache/alloc_calls

    Unable to handle kernel paging request at virtual address 2bff808aa4856d48
    Mem abort info:
      ESR = 0x96000007
      Exception class = DABT (current EL), IL = 32 bits
      SET = 0, FnV = 0
      EA = 0, S1PTW = 0
    Data abort info:
      ISV = 0, ISS = 0x00000007
      CM = 0, WnR = 0
    swapper pgtable: 64k pages, 48-bit VAs, pgdp = 0000000002498338
    [2bff808aa4856d48] pgd=00000097fcfd0003, pud=00000097fcfd0003, pmd=00000097fca30003, pte=00e8008b24850712
    Internal error: Oops: 96000007 [#1] SMP
    CPU: 3 PID: 79210 Comm: read_all Tainted: G             L    5.0.0-rc7+ #84
    Hardware name: HPE Apollo 70             /C01_APACHE_MB         , BIOS L50_5.13_1.0.6 07/10/2018
    pstate: 00400089 (nzcv daIf +PAN -UAO)
    pc : get_map+0x78/0xec
    lr : get_map+0xa0/0xec
    sp : aeff808989e3f8e0
    x29: aeff808989e3f940 x28: ffff800826200000
    x27: ffff100012d47000 x26: 9700000000002500
    x25: 0000000000000001 x24: 52ff8008200131f8
    x23: 52ff8008200130a0 x22: 52ff800820013098
    x21: ffff800826200000 x20: ffff100013172ba0
    x19: 2bff808a8971bc00 x18: ffff1000148f5538
    x17: 000000000000001b x16: 00000000000000ff
    x15: ffff1000148f5000 x14: 00000000000000d2
    x13: 0000000000000001 x12: 0000000000000000
    x11: 0000000020000002 x10: 2bff808aa4856d48
    x9 : 0000020000000000 x8 : 68ff80082620ebb0
    x7 : 0000000000000000 x6 : ffff1000105da1dc
    x5 : 0000000000000000 x4 : 0000000000000000
    x3 : 0000000000000010 x2 : 2bff808a8971bc00
    x1 : ffff7fe002098800 x0 : ffff80082620ceb0
    Process read_all (pid: 79210, stack limit = 0x00000000f65b9361)
    Call trace:
     get_map+0x78/0xec
     process_slab+0x7c/0x47c
     list_locations+0xb0/0x3c8
     alloc_calls_show+0x34/0x40
     slab_attr_show+0x34/0x48
     sysfs_kf_seq_show+0x2e4/0x570
     kernfs_seq_show+0x12c/0x1a0
     seq_read+0x48c/0xf84
     kernfs_fop_read+0xd4/0x448
     __vfs_read+0x94/0x5d4
     vfs_read+0xcc/0x194
     ksys_read+0x6c/0xe8
     __arm64_sys_read+0x68/0xb0
     el0_svc_handler+0x230/0x3bc
     el0_svc+0x8/0xc
    Code: d3467d2a 9ac92329 8b0a0e6a f9800151 (c85f7d4b)
    ---[ end trace a383a9a44ff13176 ]---
    Kernel panic - not syncing: Fatal exception
    SMP: stopping secondary CPUs
    SMP: failed to stop secondary CPUs 1-7,32,40,127
    Kernel Offset: disabled
    CPU features: 0x002,20000c18
    Memory Limit: none
    ---[ end Kernel panic - not syncing: Fatal exception ]---

Link: http://lkml.kernel.org/r/20190220020251.82039-1-cai@lca.pw
Signed-off-by: Qian Cai <cai@lca.pw>
Reviewed-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Bug: 128674696
Change-Id: I14d53cd0c3ce9672edc3b9666c68241e42d2fced
2019-09-24 17:44:15 -07:00
Andrey Konovalov
b26d7811dd UPSTREAM: kasan, slab: remove redundant kasan_slab_alloc hooks
(Upstream commit 557ea25383).

kasan_slab_alloc() calls in kmem_cache_alloc() and kmem_cache_alloc_node()
are redundant as they are already called via slab_alloc/slab_alloc_node()->
slab_post_alloc_hook()->kasan_slab_alloc().  Remove them.

Link: http://lkml.kernel.org/r/4ca1655cdcfc4379c49c50f7bf80f81c4ad01485.1550602886.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Tested-by: Qian Cai <cai@lca.pw>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgeniy Stepanov <eugenis@google.com>
Cc: Kostya Serebryany <kcc@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Bug: 128674696
Change-Id: I61be422e28a4e31f36f9ec5bea654077691b89b9
2019-09-24 17:44:15 -07:00
Andrey Konovalov
8607c71441 UPSTREAM: kasan, slab: make freelist stored without tags
(Upstream commit 51dedad06b).

Similarly to "kasan, slub: move kasan_poison_slab hook before
page_address", move kasan_poison_slab() before alloc_slabmgmt(), which
calls page_address(), to make page_address() return value to be
non-tagged.  This, combined with calling kasan_reset_tag() for off-slab
slab management object, leads to freelist being stored non-tagged.

Link: http://lkml.kernel.org/r/dfb53b44a4d00de3879a05a9f04c1f55e584f7a1.1550602886.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Tested-by: Qian Cai <cai@lca.pw>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgeniy Stepanov <eugenis@google.com>
Cc: Kostya Serebryany <kcc@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Bug: 128674696
Change-Id: I65954f8eed880ff2a0fe76a81bcf2703f707a585
2019-09-24 17:44:15 -07:00
Andrey Konovalov
137a7d4213 UPSTREAM: kasan, slab: fix conflicts with CONFIG_HARDENED_USERCOPY
(Upstream commit 219667c23c).

Similarly to commit 96fedce27e ("kasan: make tag based mode work with
CONFIG_HARDENED_USERCOPY"), we need to reset pointer tags in
__check_heap_object() in mm/slab.c before doing any pointer math.

Link: http://lkml.kernel.org/r/9a5c0f958db10e69df5ff9f2b997866b56b7effc.1550602886.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Tested-by: Qian Cai <cai@lca.pw>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgeniy Stepanov <eugenis@google.com>
Cc: Kostya Serebryany <kcc@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Bug: 128674696
Change-Id: I411184ecec0e3f77014bb330de3db5728d2065ed
2019-09-24 17:44:15 -07:00
Andrey Konovalov
d735952416 UPSTREAM: kasan: prevent tracing of tags.c
(Upstream commit dc15a8a254).

Similarly to commit 0d0c8de878 ("kasan: mark file common so ftrace
doesn't trace it") add the -pg flag to mm/kasan/tags.c to prevent
conflicts with tracing.

Link: http://lkml.kernel.org/r/9c4c3ce5ccfb894c7fe66d91de7c1da2787b4da4.1550602886.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reported-by: Qian Cai <cai@lca.pw>
Tested-by: Qian Cai <cai@lca.pw>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Kostya Serebryany <kcc@google.com>
Cc: Evgeniy Stepanov <eugenis@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Bug: 128674696
Change-Id: I41a129790bd12e699f816e27fb086a6570d4223e
2019-09-24 17:44:15 -07:00
Andrey Konovalov
aa846c8644 UPSTREAM: kasan: fix random seed generation for tag-based mode
(Upstream commit 3f41b60938).

There are two issues with assigning random percpu seeds right now:

1. We use for_each_possible_cpu() to iterate over cpus, but cpumask is
   not set up yet at the moment of kasan_init(), and thus we only set
   the seed for cpu #0.

2. A call to get_random_u32() always returns the same number and produces
   a message in dmesg, since the random subsystem is not yet initialized.

Fix 1 by calling kasan_init_tags() after cpumask is set up.

Fix 2 by using get_cycles() instead of get_random_u32(). This gives us
lower quality random numbers, but it's good enough, as KASAN is meant to
be used as a debugging tool and not a mitigation.

Link: http://lkml.kernel.org/r/1f815cc914b61f3516ed4cc9bfd9eeca9bd5d9de.1550677973.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Bug: 128674696
Change-Id: Ic4b29dfd24515f02302d5cbd0d79eab5c6f0642c
2019-09-24 17:44:15 -07:00
Qian Cai
2a9788f5f8 UPSTREAM: slub: fix SLAB_CONSISTENCY_CHECKS + KASAN_SW_TAGS
(Upstream commit 338cfaad49).

Enabling SLUB_DEBUG's SLAB_CONSISTENCY_CHECKS with KASAN_SW_TAGS
triggers endless false positives during boot below due to
check_valid_pointer() checks tagged pointers which have no addresses
that is valid within slab pages:

  BUG radix_tree_node (Tainted: G    B            ): Freelist Pointer check fails
  -----------------------------------------------------------------------------

  INFO: Slab objects=69 used=69 fp=0x          (null) flags=0x7ffffffc000200
  INFO: Object @offset=15060037153926966016 fp=0x

  Redzone: bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb  ................
  Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  Object : 00 00 00 00 00 00 00 00 18 6b 06 00 08 80 ff d0  .........k......
  Object : 18 6b 06 00 08 80 ff d0 00 00 00 00 00 00 00 00  .k..............
  Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  Redzone: bb bb bb bb bb bb bb bb                          ........
  Padding: 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a  ZZZZZZZZZZZZZZZZ
  CPU: 0 PID: 0 Comm: swapper/0 Tainted: G    B             5.0.0-rc5+ #18
  Call trace:
    dump_backtrace+0x0/0x450
    show_stack+0x20/0x2c
    __dump_stack+0x20/0x28
    dump_stack+0xa0/0xfc
    print_trailer+0x1bc/0x1d0
    object_err+0x40/0x50
    alloc_debug_processing+0xf0/0x19c
    ___slab_alloc+0x554/0x704
    kmem_cache_alloc+0x2f8/0x440
    radix_tree_node_alloc+0x90/0x2fc
    idr_get_free+0x1e8/0x6d0
    idr_alloc_u32+0x11c/0x2a4
    idr_alloc+0x74/0xe0
    worker_pool_assign_id+0x5c/0xbc
    workqueue_init_early+0x49c/0xd50
    start_kernel+0x52c/0xac4
  FIX radix_tree_node: Marking all objects used

Link: http://lkml.kernel.org/r/20190209044128.3290-1-cai@lca.pw
Signed-off-by: Qian Cai <cai@lca.pw>
Reviewed-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Change-Id: Id7d2fe26fd720bd4bd9fa9ae7f5a04be881066e7
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Bug: 128674696
2019-09-24 17:44:14 -07:00
Andrey Konovalov
712b50a15c UPSTREAM: kasan, slub: fix more conflicts with CONFIG_SLAB_FREELIST_HARDENED
(Upstream commit d36a63a943).

When CONFIG_KASAN_SW_TAGS is enabled, ptr_addr might be tagged.  Normally,
this doesn't cause any issues, as both set_freepointer() and
get_freepointer() are called with a pointer with the same tag.  However,
there are some issues with CONFIG_SLUB_DEBUG code.  For example, when
__free_slub() iterates over objects in a cache, it passes untagged
pointers to check_object().  check_object() in turns calls
get_freepointer() with an untagged pointer, which causes the freepointer
to be restored incorrectly.

Add kasan_reset_tag to freelist_ptr(). Also add a detailed comment.

Link: http://lkml.kernel.org/r/bf858f26ef32eb7bd24c665755b3aee4bc58d0e4.1550103861.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reported-by: Qian Cai <cai@lca.pw>
Tested-by: Qian Cai <cai@lca.pw>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Bug: 128674696
Change-Id: Ie57f08f676ea7a244a20f1dee98fc725594cafa6
2019-09-24 17:44:14 -07:00
Andrey Konovalov
5dbe32c94e UPSTREAM: kasan, slub: fix conflicts with CONFIG_SLAB_FREELIST_HARDENED
(Upstream commit 18e5066102).

CONFIG_SLAB_FREELIST_HARDENED hashes freelist pointer with the address of
the object where the pointer gets stored.  With tag based KASAN we don't
account for that when building freelist, as we call set_freepointer() with
the first argument untagged.  This patch changes the code to properly
propagate tags throughout the loop.

Link: http://lkml.kernel.org/r/3df171559c52201376f246bf7ce3184fe21c1dc7.1549921721.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reported-by: Qian Cai <cai@lca.pw>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Kostya Serebryany <kcc@google.com>
Cc: Evgeniy Stepanov <eugenis@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Bug: 128674696
Change-Id: I218d23e0fe3164f6f03d4f08bb93630f3e496f82
2019-09-24 17:44:14 -07:00
Andrey Konovalov
d79e51f2a9 UPSTREAM: kasan, slub: move kasan_poison_slab hook before page_address
(Upstream commit a710122428).

With tag based KASAN page_address() looks at the page flags to see whether
the resulting pointer needs to have a tag set.  Since we don't want to set
a tag when page_address() is called on SLAB pages, we call
page_kasan_tag_reset() in kasan_poison_slab().  However in allocate_slab()
page_address() is called before kasan_poison_slab().  Fix it by changing
the order.

[andreyknvl@google.com: fix compilation error when CONFIG_SLUB_DEBUG=n]
  Link: http://lkml.kernel.org/r/ac27cc0bbaeb414ed77bcd6671a877cf3546d56e.1550066133.git.andreyknvl@google.com
Link: http://lkml.kernel.org/r/cd895d627465a3f1c712647072d17f10883be2a1.1549921721.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgeniy Stepanov <eugenis@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kostya Serebryany <kcc@google.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Qian Cai <cai@lca.pw>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Bug: 128674696
Change-Id: I53ade71e532b3e4163b84a3a23c7c54ab2d059bd
2019-09-24 17:44:14 -07:00
Andrey Konovalov
11543367c3 UPSTREAM: kasan, kmemleak: pass tagged pointers to kmemleak
(Upstream commit 53128245b4).

Right now we call kmemleak hooks before assigning tags to pointers in
KASAN hooks.  As a result, when an objects gets allocated, kmemleak sees a
differently tagged pointer, compared to the one it sees when the object
gets freed.  Fix it by calling KASAN hooks before kmemleak's ones.

Link: http://lkml.kernel.org/r/cd825aa4897b0fc37d3316838993881daccbe9f5.1549921721.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reported-by: Qian Cai <cai@lca.pw>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgeniy Stepanov <eugenis@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kostya Serebryany <kcc@google.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Bug: 128674696
Change-Id: I7766731cf2fe22effd91bfb89da915355d0e7981
2019-09-24 17:44:14 -07:00
Andrey Konovalov
ceface4ee3 UPSTREAM: kasan: fix assigning tags twice
(Upstream commit e1db95befb).

When an object is kmalloc()'ed, two hooks are called: kasan_slab_alloc()
and kasan_kmalloc().  Right now we assign a tag twice, once in each of the
hooks.  Fix it by assigning a tag only in the former hook.

Link: http://lkml.kernel.org/r/ce8c6431da735aa7ec051fd6497153df690eb021.1549921721.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgeniy Stepanov <eugenis@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kostya Serebryany <kcc@google.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Qian Cai <cai@lca.pw>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Bug: 128674696
Change-Id: I70f85dda8fcbcc796ebde8294a6f110d390bff3f
2019-09-24 17:44:14 -07:00
Anders Roxell
b4d4745fe4 UPSTREAM: kasan: mark file common so ftrace doesn't trace it
(Upstream commit 0d0c8de878).

When option CONFIG_KASAN is enabled toghether with ftrace, function
ftrace_graph_caller() gets in to a recursion, via functions
kasan_check_read() and kasan_check_write().

 Breakpoint 2, ftrace_graph_caller () at ../arch/arm64/kernel/entry-ftrace.S:179
 179             mcount_get_pc             x0    //     function's pc
 (gdb) bt
 #0  ftrace_graph_caller () at ../arch/arm64/kernel/entry-ftrace.S:179
 #1  0xffffff90101406c8 in ftrace_caller () at ../arch/arm64/kernel/entry-ftrace.S:151
 #2  0xffffff90106fd084 in kasan_check_write (p=0xffffffc06c170878, size=4) at ../mm/kasan/common.c:105
 #3  0xffffff90104a2464 in atomic_add_return (v=<optimized out>, i=<optimized out>) at ./include/generated/atomic-instrumented.h:71
 #4  atomic_inc_return (v=<optimized out>) at ./include/generated/atomic-fallback.h:284
 #5  trace_graph_entry (trace=0xffffffc03f5ff380) at ../kernel/trace/trace_functions_graph.c:441
 #6  0xffffff9010481774 in trace_graph_entry_watchdog (trace=<optimized out>) at ../kernel/trace/trace_selftest.c:741
 #7  0xffffff90104a185c in function_graph_enter (ret=<optimized out>, func=<optimized out>, frame_pointer=18446743799894897728, retp=<optimized out>) at ../kernel/trace/trace_functions_graph.c:196
 #8  0xffffff9010140628 in prepare_ftrace_return (self_addr=18446743592948977792, parent=0xffffffc03f5ff418, frame_pointer=18446743799894897728) at ../arch/arm64/kernel/ftrace.c:231
 #9  0xffffff90101406f4 in ftrace_graph_caller () at ../arch/arm64/kernel/entry-ftrace.S:182
 Backtrace stopped: previous frame identical to this frame (corrupt stack?)
 (gdb)

Rework so that the kasan implementation isn't traced.

Link: http://lkml.kernel.org/r/20181212183447.15890-1-anders.roxell@linaro.org
Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
Acked-by: Dmitry Vyukov <dvyukov@google.com>
Tested-by: Dmitry Vyukov <dvyukov@google.com>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Bug: 128674696
Change-Id: Id4dc25b795f81b4193c5f861657e9091acd99cef
2019-09-24 17:44:14 -07:00
Andrey Konovalov
e545826cb2 UPSTREAM: kasan, arm64: remove redundant ARCH_SLAB_MINALIGN define
(Upstream commit 7fa1e2e6af).

Defining ARCH_SLAB_MINALIGN in arch/arm64/include/asm/cache.h when KASAN
is off is not needed, as it is defined in defined in include/linux/slab.h
as ifndef.

Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Bug: 128674696
Change-Id: I27d13c0ed9f8ab2488028b526561f90b3e2eec0c
2019-09-24 17:44:14 -07:00
Andrey Konovalov
0f007a2bf6 UPSTREAM: kasan: fix krealloc handling for tag-based mode
(Upstream commit a3fe7cdf02).

Right now tag-based KASAN can retag the memory that is reallocated via
krealloc and return a differently tagged pointer even if the same slab
object gets used and no reallocated technically happens.

There are a few issues with this approach.  One is that krealloc callers
can't rely on comparing the return value with the passed argument to
check whether reallocation happened.  Another is that if a caller knows
that no reallocation happened, that it can access object memory through
the old pointer, which leads to false positives.  Look at
nf_ct_ext_add() to see an example.

Fix this by keeping the same tag if the memory don't actually gets
reallocated during krealloc.

Link: http://lkml.kernel.org/r/bb2a71d17ed072bcc528cbee46fcbd71a6da3be4.1546540962.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Bug: 128674696
Change-Id: Ie9bd73c43fa76ac2ba946bfbd2cb88e5c0000dfb
2019-09-24 17:44:14 -07:00
Andrey Konovalov
d8c656e717 UPSTREAM: kasan: make tag based mode work with CONFIG_HARDENED_USERCOPY
(Upstream commit 96fedce27e).

With CONFIG_HARDENED_USERCOPY enabled __check_heap_object() compares and
then subtracts a potentially tagged pointer with a non-tagged address of
the page that this pointer belongs to, which leads to unexpected
behavior.

Untag the pointer in __check_heap_object() before doing any of these
operations.

Link: http://lkml.kernel.org/r/7e756a298d514c4482f52aea6151db34818d395d.1546540962.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Bug: 128674696
Change-Id: Id1a000155fe12fc39b3caee7a097f9bea0ba3fce
2019-09-24 17:44:14 -07:00
Andrey Konovalov
c84291fd95 UPSTREAM: kasan, arm64: use ARCH_SLAB_MINALIGN instead of manual aligning
(Upstream commit eb214f2dda).

Instead of changing cache->align to be aligned to KASAN_SHADOW_SCALE_SIZE
in kasan_cache_create() we can reuse the ARCH_SLAB_MINALIGN macro.

Link: http://lkml.kernel.org/r/52ddd881916bcc153a9924c154daacde78522227.1546540962.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Suggested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Bug: 128674696
Change-Id: Ia1c8de45c621b68555f77a569431e232ff4dc781
2019-09-24 17:44:14 -07:00
Qian Cai
88299f649b BACKPORT: mm/memblock.c: skip kmemleak for kasan_init()
(Upstream commit fed84c7852).

Kmemleak does not play well with KASAN (tested on both HPE Apollo 70 and
Huawei TaiShan 2280 aarch64 servers).

After calling start_kernel()->setup_arch()->kasan_init(), kmemleak early
log buffer went from something like 280 to 260000 which caused kmemleak
disabled and crash dump memory reservation failed.  The multitude of
kmemleak_alloc() calls is from nested loops while KASAN is setting up full
memory mappings, so let early kmemleak allocations skip those
memblock_alloc_internal() calls came from kasan_init() given that those
early KASAN memory mappings should not reference to other memory.  Hence,
no kmemleak false positives.

kasan_init
  kasan_map_populate [1]
    kasan_pgd_populate [2]
      kasan_pud_populate [3]
        kasan_pmd_populate [4]
          kasan_pte_populate [5]
            kasan_alloc_zeroed_page
              memblock_alloc_try_nid
                memblock_alloc_internal
                  kmemleak_alloc

[1] for_each_memblock(memory, reg)
[2] while (pgdp++, addr = next, addr != end)
[3] while (pudp++, addr = next, addr != end && pud_none(READ_ONCE(*pudp)))
[4] while (pmdp++, addr = next, addr != end && pmd_none(READ_ONCE(*pmdp)))
[5] while (ptep++, addr = next, addr != end && pte_none(READ_ONCE(*ptep)))

Link: http://lkml.kernel.org/r/1543442925-17794-1-git-send-email-cai@gmx.us
Signed-off-by: Qian Cai <cai@gmx.us>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Change-Id: I2423d511c3938c882c738341673b13b3beff5475
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Bug: 128674696
2019-09-24 17:44:13 -07:00
Andrey Konovalov
f7de9038cd UPSTREAM: kasan: add SPDX-License-Identifier mark to source files
(Upstream commit e886bf9d9a).

This patch adds a "SPDX-License-Identifier: GPL-2.0" mark to all source
files under mm/kasan.

Link: http://lkml.kernel.org/r/bce2d1e618afa5142e81961ab8fa4b4165337380.1544099024.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Bug: 128674696
Change-Id: Ia5cdf04c5183e6c2cb75d98d60e6f4f5d961cd6e
2019-09-24 17:44:13 -07:00
Andrey Konovalov
6d24905328 UPSTREAM: kasan: update documentation
(Upstream commit b3b0e6accb).

This patch updates KASAN documentation to reflect the addition of the new
tag-based mode.

Link: http://lkml.kernel.org/r/aabef9de317c54b8a3919a4946ce534c6576726a.1544099024.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Bug: 128674696
Change-Id: Ie0a468a51aa0ad02f00fdbed34605bca9630e398
2019-09-24 17:44:13 -07:00
Andrey Konovalov
2d4373a482 UPSTREAM: kasan, arm64: select HAVE_ARCH_KASAN_SW_TAGS
(Upstream commit 2d4acb9087).

Now, that all the necessary infrastructure code has been introduced,
select HAVE_ARCH_KASAN_SW_TAGS for arm64 to enable software tag-based
KASAN mode.

Link: http://lkml.kernel.org/r/25abce9a21d0c1df2d9d72488aced418c3465d7b.1544099024.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Bug: 128674696
Change-Id: I8e320ea0b7d6cacf358aa7cc72f2399608474bcd
2019-09-24 17:44:13 -07:00
Andrey Konovalov
c80e94ddfc UPSTREAM: kasan: add __must_check annotations to kasan hooks
(Upstream commit 66afc7f1e0).

This patch adds __must_check annotations to kasan hooks that return a
pointer to make sure that a tagged pointer always gets propagated.

Link: http://lkml.kernel.org/r/03b269c5e453945f724bfca3159d4e1333a8fb1c.1544099024.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Suggested-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Bug: 128674696
Change-Id: I758f33506b67ed5d4b7539745db311ab31c37f46
2019-09-24 17:44:13 -07:00
Andrey Konovalov
be21fa3044 UPSTREAM: kasan, mm, arm64: tag non slab memory allocated via pagealloc
(Upstream commit 2813b9c029).

Tag-based KASAN doesn't check memory accesses through pointers tagged with
0xff.  When page_address is used to get pointer to memory that corresponds
to some page, the tag of the resulting pointer gets set to 0xff, even
though the allocated memory might have been tagged differently.

For slab pages it's impossible to recover the correct tag to return from
page_address, since the page might contain multiple slab objects tagged
with different values, and we can't know in advance which one of them is
going to get accessed.  For non slab pages however, we can recover the tag
in page_address, since the whole page was marked with the same tag.

This patch adds tagging to non slab memory allocated with pagealloc.  To
set the tag of the pointer returned from page_address, the tag gets stored
to page->flags when the memory gets allocated.

Link: http://lkml.kernel.org/r/d758ddcef46a5abc9970182b9137e2fbee202a2c.1544099024.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Bug: 128674696
Change-Id: I500bdf42462fee0ee14495a6be51815e7e44460f
2019-09-24 17:44:13 -07:00
Andrey Konovalov
fd535b3748 UPSTREAM: kasan, arm64: add brk handler for inline instrumentation
(Upstream commit 41eea9cd23).

Tag-based KASAN inline instrumentation mode (which embeds checks of shadow
memory into the generated code, instead of inserting a callback) generates
a brk instruction when a tag mismatch is detected.

This commit adds a tag-based KASAN specific brk handler, that decodes the
immediate value passed to the brk instructions (to extract information
about the memory access that triggered the mismatch), reads the register
values (x0 contains the guilty address) and reports the bug.

Link: http://lkml.kernel.org/r/c91fe7684070e34dc34b419e6b69498f4dcacc2d.1544099024.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Bug: 128674696
Change-Id: I9bd12777aad266b54e285f033c9ca2ddda887e31
2019-09-24 17:44:13 -07:00
Andrey Konovalov
854b1b3576 UPSTREAM: kasan: add hooks implementation for tag-based mode
(Upstream commit 7f94ffbc4c).

This commit adds tag-based KASAN specific hooks implementation and
adjusts common generic and tag-based KASAN ones.

1. When a new slab cache is created, tag-based KASAN rounds up the size of
   the objects in this cache to KASAN_SHADOW_SCALE_SIZE (== 16).

2. On each kmalloc tag-based KASAN generates a random tag, sets the shadow
   memory, that corresponds to this object to this tag, and embeds this
   tag value into the top byte of the returned pointer.

3. On each kfree tag-based KASAN poisons the shadow memory with a random
   tag to allow detection of use-after-free bugs.

The rest of the logic of the hook implementation is very much similar to
the one provided by generic KASAN. Tag-based KASAN saves allocation and
free stack metadata to the slab object the same way generic KASAN does.

Link: http://lkml.kernel.org/r/bda78069e3b8422039794050ddcb2d53d053ed41.1544099024.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Bug: 128674696
Change-Id: I23c40472207cba40dc962bb182225e378322249e
2019-09-24 17:44:13 -07:00
Andrey Konovalov
cf9a2eedfd UPSTREAM: mm: move obj_to_index to include/linux/slab_def.h
(Upstream commit 5b7c414822).

While with SLUB we can actually preassign tags for caches with contructors
and store them in pointers in the freelist, SLAB doesn't allow that since
the freelist is stored as an array of indexes, so there are no pointers to
store the tags.

Instead we compute the tag twice, once when a slab is created before
calling the constructor and then again each time when an object is
allocated with kmalloc.  Tag is computed simply by taking the lowest byte
of the index that corresponds to the object.  However in kasan_kmalloc we
only have access to the objects pointer, so we need a way to find out
which index this object corresponds to.

This patch moves obj_to_index from slab.c to include/linux/slab_def.h to
be reused by KASAN.

Link: http://lkml.kernel.org/r/c02cd9e574cfd93858e43ac94b05e38f891fef64.1544099024.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Bug: 128674696
Change-Id: I6cb3332ea05e6152ab8de0490171ed5d4947def3
2019-09-24 17:44:13 -07:00
Andrey Konovalov
f8adce49ea UPSTREAM: kasan: add bug reporting routines for tag-based mode
(Upstream commit 121e8f81d3).

This commit adds rountines, that print tag-based KASAN error reports.
Those are quite similar to generic KASAN, the difference is:

1. The way tag-based KASAN finds the first bad shadow cell (with a
   mismatching tag). Tag-based KASAN compares memory tags from the shadow
   memory to the pointer tag.

2. Tag-based KASAN reports all bugs with the "KASAN: invalid-access"
   header.

Also simplify generic KASAN find_first_bad_addr.

Link: http://lkml.kernel.org/r/aee6897b1bd077732a315fd84c6b4f234dbfdfcb.1544099024.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Bug: 128674696
Change-Id: I20ef95c8c568df73adf69b140dbbf4cd9da52f34
2019-09-24 17:44:13 -07:00
Andrey Konovalov
1ff3965086 UPSTREAM: kasan: split out generic_report.c from report.c
(Upstream commit 11cd3cd69a).

Move generic KASAN specific error reporting routines to generic_report.c
without any functional changes, leaving common error reporting code in
report.c to be later reused by tag-based KASAN.

Link: http://lkml.kernel.org/r/ba48c32f8e5aefedee78998ccff0413bee9e0f5b.1544099024.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Bug: 128674696
Change-Id: Ic65fb3da92607d345be5bbe2c486269d1db53745
2019-09-24 17:44:13 -07:00
Andrey Konovalov
70b223ca1d UPSTREAM: kasan, mm: perform untagged pointers comparison in krealloc
(Upstream commit 772a2fa50f).

The krealloc function checks where the same buffer was reused or a new one
allocated by comparing kernel pointers.  Tag-based KASAN changes memory
tag on the krealloc'ed chunk of memory and therefore also changes the
pointer tag of the returned pointer.  Therefore we need to perform
comparison on untagged (with tags reset) pointers to check whether it's
the same memory region or not.

Link: http://lkml.kernel.org/r/14f6190d7846186a3506cd66d82446646fe65090.1544099024.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Bug: 128674696
Change-Id: I1e64158a5a0d683fc19c76296bc5fa345639bf30
2019-09-24 17:44:12 -07:00
Andrey Konovalov
1a64068752 BACKPORT: kasan, arm64: enable top byte ignore for the kernel
(Upstream commit 21696c1613).

Tag-based KASAN uses the Top Byte Ignore feature of arm64 CPUs to store a
pointer tag in the top byte of each pointer.  This commit enables the
TCR_TBI1 bit, which enables Top Byte Ignore for the kernel, when tag-based
KASAN is used.

Link: http://lkml.kernel.org/r/f51eca084c8cdb2f3a55195fe342dc8953b7aead.1544099024.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Change-Id: Ia31aff11e6b8b80fbbd0be7580f83ee1f5e4db72
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Bug: 128674696
2019-09-24 17:44:12 -07:00
Andrey Konovalov
479d328d98 BACKPORT: kasan, arm64: fix up fault handling logic
(Upstream commit 356607f21e).

Right now arm64 fault handling code removes pointer tags from addresses
covered by TTBR0 in faults taken from both EL0 and EL1, but doesn't do
that for pointers covered by TTBR1.

This patch adds two helper functions is_ttbr0_addr() and is_ttbr1_addr(),
where the latter one accounts for the fact that TTBR1 pointers might be
tagged when tag-based KASAN is in use, and uses these helper functions to
perform pointer checks in arch/arm64/mm/fault.c.

Link: http://lkml.kernel.org/r/3f349b0e9e48b5df3298a6b4ae0634332274494a.1544099024.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Suggested-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Change-Id: Idbb44bff2c2efd296a2e373eaa74f1c0fa17ecca
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Bug: 128674696
2019-09-24 17:44:12 -07:00
Andrey Konovalov
9900949b99 UPSTREAM: kasan: preassign tags to objects with ctors or SLAB_TYPESAFE_BY_RCU
(Upstream commit 4d176711ea).

An object constructor can initialize pointers within this objects based on
the address of the object.  Since the object address might be tagged, we
need to assign a tag before calling constructor.

The implemented approach is to assign tags to objects with constructors
when a slab is allocated and call constructors once as usual.  The
downside is that such object would always have the same tag when it is
reallocated, so we won't catch use-after-frees on it.

Also pressign tags for objects from SLAB_TYPESAFE_BY_RCU caches, since
they can be validy accessed after having been freed.

Link: http://lkml.kernel.org/r/f158a8a74a031d66f0a9398a5b0ed453c37ba09a.1544099024.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Bug: 128674696
Change-Id: I48b1de0516b9998f3b3e3917a15dd0bde27897cf
2019-09-24 17:44:12 -07:00
Andrey Konovalov
5f4af678b8 UPSTREAM: kasan, arm64: untag address in _virt_addr_is_linear
(Upstream commit e71fe3f921).

virt_addr_is_linear (which is used by virt_addr_valid) assumes that the
top byte of the address is 0xff, which isn't always the case with
tag-based KASAN.

This patch resets the tag in this macro.

Link: http://lkml.kernel.org/r/df73a37dd5ed37f4deaf77bc718e9f2e590e69b1.1544099024.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Bug: 128674696
Change-Id: I8b5de086ef1a63271bc72fefc3ab22f1bc9ac0a0
2019-09-24 17:44:12 -07:00
Andrey Konovalov
f8ce5f5926 UPSTREAM: kasan: add tag related helper functions
(Upstream commit 3c9e3aa110).

This commit adds a few helper functions, that are meant to be used to work
with tags embedded in the top byte of kernel pointers: to set, to get or
to reset the top byte.

Link: http://lkml.kernel.org/r/f6c6437bb8e143bc44f42c3c259c62e734be7935.1544099024.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Bug: 128674696
Change-Id: I6a46eb172205fe869d126ae296f64d44e007ac88
2019-09-24 17:44:12 -07:00
Andrey Konovalov
b32b4dfdb2 UPSTREAM: arm64: move untagged_addr macro from uaccess.h to memory.h
(Upstream commit 9c23f84723).

Move the untagged_addr() macro from arch/arm64/include/asm/uaccess.h
to arch/arm64/include/asm/memory.h to be later reused by KASAN.

Also make the untagged_addr() macro accept all kinds of address types
(void *, unsigned long, etc.). This allows not to specify type casts in
each place where the macro is used. This is done by using __typeof__.

Link: http://lkml.kernel.org/r/2e9ef8d2ed594106eca514b268365b5419113f6a.1544099024.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Bug: 128674696
Change-Id: I1dc81f9698ade663dcf5a30a918eed29a83d8595
2019-09-24 17:44:12 -07:00
Andrey Konovalov
fe1cf9c054 BACKPORT: kasan: initialize shadow to 0xff for tag-based mode
Use kasan_alloc_zeroed_page instead of defining kasan_alloc_raw_page.

(Upstream commit 080eb83f54).

A tag-based KASAN shadow memory cell contains a memory tag, that
corresponds to the tag in the top byte of the pointer, that points to that
memory.  The native top byte value of kernel pointers is 0xff, so with
tag-based KASAN we need to initialize shadow memory to 0xff.

[cai@lca.pw: arm64: skip kmemleak for KASAN again\
  Link: http://lkml.kernel.org/r/20181226020550.63712-1-cai@lca.pw
Link: http://lkml.kernel.org/r/5cc1b789aad7c99cf4f3ec5b328b147ad53edb40.1544099024.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Bug: 128674696
Change-Id: I370390e529de29fee99820f3ae2fc3d0408379ef
2019-09-24 17:44:12 -07:00
Andrey Konovalov
02e8a3fcb0 BACKPORT: kasan: rename kasan_zero_page to kasan_early_shadow_page
(Upstream commit 9577dd7486).

With tag based KASAN mode the early shadow value is 0xff and not 0x00, so
this patch renames kasan_zero_(page|pte|pmd|pud|p4d) to
kasan_early_shadow_(page|pte|pmd|pud|p4d) to avoid confusion.

Link: http://lkml.kernel.org/r/3fed313280ebf4f88645f5b89ccbc066d320e177.1544099024.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Suggested-by: Mark Rutland <mark.rutland@arm.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Bug: 128674696
Change-Id: I22d043b1f2ce489b12832f6f1ba1593c4ccdaedf
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
2019-09-24 17:44:12 -07:00
Andrey Konovalov
b6ebbacf85 UPSTREAM: kasan, arm64: adjust shadow size for tag-based mode
(Upstream commit b2f557eae9).

Tag-based KASAN uses 1 shadow byte for 16 bytes of kernel memory, so it
requires 1/16th of the kernel virtual address space for the shadow memory.

This commit sets KASAN_SHADOW_SCALE_SHIFT to 4 when the tag-based KASAN
mode is enabled.

Link: http://lkml.kernel.org/r/308b6bd49f756bb5e533be93c6f085ba99b30339.1544099024.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Bug: 128674696
Change-Id: Ia1e34daa26106be956cc20078f689794c95845d3
2019-09-24 17:44:12 -07:00
Andrey Konovalov
8712cc728d BACKPORT: kasan: add CONFIG_KASAN_GENERIC and CONFIG_KASAN_SW_TAGS
The conflict during backport is caused by the
include/linux/compiler_attributes.h file not being present.

(Upstream commit 2bd926b439).

This commit splits the current CONFIG_KASAN config option into two:
1. CONFIG_KASAN_GENERIC, that enables the generic KASAN mode (the one
   that exists now);
2. CONFIG_KASAN_SW_TAGS, that enables the software tag-based KASAN mode.

The name CONFIG_KASAN_SW_TAGS is chosen as in the future we will have
another hardware tag-based KASAN mode, that will rely on hardware memory
tagging support in arm64.

With CONFIG_KASAN_SW_TAGS enabled, compiler options are changed to
instrument kernel files with -fsantize=kernel-hwaddress (except the ones
for which KASAN_SANITIZE := n is set).

Both CONFIG_KASAN_GENERIC and CONFIG_KASAN_SW_TAGS support both
CONFIG_KASAN_INLINE and CONFIG_KASAN_OUTLINE instrumentation modes.

This commit also adds empty placeholder (for now) implementation of
tag-based KASAN specific hooks inserted by the compiler and adjusts
common hooks implementation.

While this commit adds the CONFIG_KASAN_SW_TAGS config option, this option
is not selectable, as it depends on HAVE_ARCH_KASAN_SW_TAGS, which we will
enable once all the infrastracture code has been added.

Link: http://lkml.kernel.org/r/b2550106eb8a68b10fefbabce820910b115aa853.1544099024.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Change-Id: Id95c0c0b6857c6b30f2bea4597aea6c90273ef89
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Bug: 128674696
2019-09-24 17:44:12 -07:00
Andrey Konovalov
3915eb8bdf UPSTREAM: kasan: rename source files to reflect the new naming scheme
(Upstream commit b938fcf427).

We now have two KASAN modes: generic KASAN and tag-based KASAN.  Rename
kasan.c to generic.c to reflect that.  Also rename kasan_init.c to init.c
as it contains initialization code for both KASAN modes.

Link: http://lkml.kernel.org/r/88c6fd2a883e459e6242030497230e5fb0d44d44.1544099024.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Bug: 128674696
Change-Id: I375981e1e9013517f073b29e27e750c48ba24879
2019-09-24 17:44:11 -07:00
Andrey Konovalov
17045587b4 UPSTREAM: kasan: move common generic and tag-based code to common.c
(Upstream commit bffa986c6f).

Tag-based KASAN reuses a significant part of the generic KASAN code, so
move the common parts to common.c without any functional changes.

Link: http://lkml.kernel.org/r/114064d002356e03bb8cc91f7835e20dc61b51d9.1544099024.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Bug: 128674696
Change-Id: Iffe8a07fa53751e4232c8458aab0a8adda951f55
2019-09-24 17:44:11 -07:00
Andrey Konovalov
9938c593b5 UPSTREAM: kasan, slub: handle pointer tags in early_kmem_cache_node_alloc
(Upstream commit 12b2238699).

The previous patch updated KASAN hooks signatures and their usage in SLAB
and SLUB code, except for the early_kmem_cache_node_alloc function.  This
patch handles that function separately, as it requires to reorder some of
the initialization code to correctly propagate a tagged pointer in case a
tag is assigned by kasan_kmalloc.

Link: http://lkml.kernel.org/r/fc8d0fdcf733a7a52e8d0daaa650f4736a57de8c.1544099024.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Bug: 128674696
Change-Id: Ifcfcd2a679ebf9444a1c6525ad55b3a65a4a5941
2019-09-24 17:44:11 -07:00