commit 9acc89d31f upstream.
EVM_ALLOW_METADATA_WRITES is an EVM initialization flag that can be set to
temporarily disable metadata verification until all xattrs/attrs necessary
to verify an EVM portable signature are copied to the file. This flag is
cleared when EVM is initialized with an HMAC key, to avoid that the HMAC is
calculated on unverified xattrs/attrs.
Currently EVM unnecessarily denies setting this flag if EVM is initialized
with a public key, which is not a concern as it cannot be used to trust
xattrs/attrs updates. This patch removes this limitation.
Fixes: ae1ba1676b ("EVM: Allow userland to permit modification of EVM-protected metadata")
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Cc: stable@vger.kernel.org # 4.16.x
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 9eea290429 upstream.
evm_inode_init_security() requires an HMAC key to calculate the HMAC on
initial xattrs provided by LSMs. However, it checks generically whether a
key has been loaded, including also public keys, which is not correct as
public keys are not suitable to calculate the HMAC.
Originally, support for signature verification was introduced to verify a
possibly immutable initial ram disk, when no new files are created, and to
switch to HMAC for the root filesystem. By that time, an HMAC key should
have been loaded and usable to calculate HMACs for new files.
More recently support for requiring an HMAC key was removed from the
kernel, so that signature verification can be used alone. Since this is a
legitimate use case, evm_inode_init_security() should not return an error
when no HMAC key has been loaded.
This patch fixes this problem by replacing the evm_key_loaded() check with
a check of the EVM_INIT_HMAC flag in evm_initialized.
Fixes: 26ddabfe96 ("evm: enable EVM when X509 certificate is loaded")
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Cc: stable@vger.kernel.org # 4.5.x
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 7c6986ade6 upstream.
In raise_backtrace_ipi() we iterate through the cpumask of CPUs, sending
each an IPI asking them to do a backtrace, but we don't wait for the
backtrace to happen.
We then iterate through the CPU mask again, and if any CPU hasn't done
the backtrace and cleared itself from the mask, we print a trace on its
behalf, noting that the trace may be "stale".
This works well enough when a CPU is not responding, because in that
case it doesn't receive the IPI and the sending CPU is left to print the
trace. But when all CPUs are responding we are left with a race between
the sending and receiving CPUs, if the sending CPU wins the race then it
will erroneously print a trace.
This leads to spurious "stale" traces from the sending CPU, which can
then be interleaved messily with the receiving CPU, note the CPU
numbers, eg:
[ 1658.929157][ C7] rcu: Stack dump where RCU GP kthread last ran:
[ 1658.929223][ C7] Sending NMI from CPU 7 to CPUs 1:
[ 1658.929303][ C1] NMI backtrace for cpu 1
[ 1658.929303][ C7] CPU 1 didn't respond to backtrace IPI, inspecting paca.
[ 1658.929362][ C1] CPU: 1 PID: 325 Comm: kworker/1:1H Tainted: G W E 5.13.0-rc2+ #46
[ 1658.929405][ C7] irq_soft_mask: 0x01 in_mce: 0 in_nmi: 0 current: 325 (kworker/1:1H)
[ 1658.929465][ C1] Workqueue: events_highpri test_work_fn [test_lockup]
[ 1658.929549][ C7] Back trace of paca->saved_r1 (0xc0000000057fb400) (possibly stale):
[ 1658.929592][ C1] NIP: c00000000002cf50 LR: c008000000820178 CTR: c00000000002cfa0
To fix it, change the logic so that the sending CPU waits 5s for the
receiving CPU to print its trace. If the receiving CPU prints its trace
successfully then the sending CPU just continues, avoiding any spurious
"stale" trace.
This has the added benefit of allowing all CPUs to print their traces in
order and avoids any interleaving of their output.
Fixes: 5cc05910f2 ("powerpc/64s: Wire up arch_trigger_cpumask_backtrace()")
Cc: stable@vger.kernel.org # v4.18+
Reported-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210625140408.3351173-1-mpe@ellerman.id.au
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 9913d5745b upstream.
All internal use cases for tracepoint_probe_register() is set to not ever
be called with the same function and data. If it is, it is considered a
bug, as that means the accounting of handling tracepoints is corrupted.
If the function and data for a tracepoint is already registered when
tracepoint_probe_register() is called, it will call WARN_ON_ONCE() and
return with EEXISTS.
The BPF system call can end up calling tracepoint_probe_register() with
the same data, which now means that this can trigger the warning because
of a user space process. As WARN_ON_ONCE() should not be called because
user space called a system call with bad data, there needs to be a way to
register a tracepoint without triggering a warning.
Enter tracepoint_probe_register_may_exist(), which can be called, but will
not cause a WARN_ON() if the probe already exists. It will still error out
with EEXIST, which will then be sent to the user space that performed the
BPF system call.
This keeps the previous testing for issues with other users of the
tracepoint code, while letting BPF call it with duplicated data and not
warn about it.
Link: https://lore.kernel.org/lkml/20210626135845.4080-1-penguin-kernel@I-love.SAKURA.ne.jp/
Link: https://syzkaller.appspot.com/bug?id=41f4318cf01762389f4d1c1c459da4f542fe5153
Cc: stable@vger.kernel.org
Fixes: c4f6699dfc ("bpf: introduce BPF_RAW_TRACEPOINT")
Reported-by: syzbot <syzbot+721aa903751db87aa244@syzkaller.appspotmail.com>
Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Tested-by: syzbot+721aa903751db87aa244@syzkaller.appspotmail.com
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 26c5637310 upstream.
With the addition of simple mathematical operations (plus and minus), the
parsing of the "sym-offset" modifier broke, as it took the '-' part of the
"sym-offset" as a minus, and tried to break it up into a mathematical
operation of "field.sym - offset", in which case it failed to parse
(unless the event had a field called "offset").
Both .sym and .sym-offset modifiers should not be entered into
mathematical calculations anyway. If ".sym-offset" is found in the
modifier, then simply make it not an operation that can be calculated on.
Link: https://lkml.kernel.org/r/20210707110821.188ae255@oasis.local.home
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: stable@vger.kernel.org
Fixes: 100719dcef ("tracing: Add simple expression support to hist triggers")
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 314538041b upstream.
In AP mode WPA2-PSK connections were not established.
The reason was that the AP was sending the first message
of the 4 way handshake encrypted, even though no pairwise
key had (correctly) yet been set.
Encryption was enabled if the "security_enable" driver flag
was set and encryption was not explicitly disabled by
IEEE80211_TX_INTFL_DONT_ENCRYPT.
However security_enable was set when *any* key, including
the AP GTK key, had been set which was causing unwanted
encryption even if no key was avaialble for the unicast
packet to be sent.
Fix this by adding a check that we have a key and drop
the old security_enable driver flag which is insufficient
and redundant.
The Redpine downstream out of tree driver does it this way too.
Regarding the Fixes tag the actual code being modified was
introduced earlier, with the original driver submission, in
dad0d04fa7 ("rsi: Add RS9113 wireless driver"), however
at that time AP mode was not yet supported so there was
no bug at that point.
So I have tagged the introduction of AP support instead
which was part of the patch set "rsi: support for AP mode" [1]
It is not clear whether AP WPA has ever worked, I can see nothing
on the kernel side that broke it afterwards yet the AP support
patch series says "Tests are performed to confirm aggregation,
connections in WEP and WPA/WPA2 security."
One possibility is that the initial tests were done with a modified
userspace (hostapd).
[1] https://www.spinics.net/lists/linux-wireless/msg165302.html
Signed-off-by: Martin Fuzzey <martin.fuzzey@flowbird.group>
Fixes: 38ef62353a ("rsi: security enhancements for AP mode")
CC: stable@vger.kernel.org
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/1622564459-24430-1-git-send-email-martin.fuzzey@flowbird.group
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit fb312ac5cc upstream.
I got this crash more times during debugging of PCIe controller and crash
happens somehow at the time when PCIe kernel code started link retraining (as
part of ASPM code) when at the same time PCIe link went down and ath9k probably
executed hw reset procedure.
Currently I'm not able to reproduce this issue as it looks like to be
some race condition between link training, ASPM, link down and reset
path. And as always, race conditions which depends on more input
parameters are hard to reproduce as it depends on precise timings.
But it is clear that pointers are zero in this case and should be
properly filled as same code pattern is used in ath9k_stop() function.
Anyway I was able to reproduce this crash by manually triggering ath
reset worker prior putting card up. I created simple patch to export
reset functionality via debugfs and use it to "simulate" of triggering
reset. s proved that NULL-pointer dereference issue is there.
Function ath9k_hw_reset() is dereferencing chan structure pointer, so it
needs to be non-NULL pointer.
Function ath9k_stop() already contains code which sets ah->curchan to valid
non-NULL pointer prior calling ath9k_hw_reset() function.
Add same code pattern also into ath_reset_internal() function to prevent
kernel NULL pointer dereference in ath9k_hw_reset() function.
This change fixes kernel NULL pointer dereference in ath9k_hw_reset() which
is caused by calling ath9k_hw_reset() from ath_reset_internal() with NULL
chan structure.
[ 45.334305] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000008
[ 45.344417] Mem abort info:
[ 45.347301] ESR = 0x96000005
[ 45.350448] EC = 0x25: DABT (current EL), IL = 32 bits
[ 45.356166] SET = 0, FnV = 0
[ 45.359350] EA = 0, S1PTW = 0
[ 45.362596] Data abort info:
[ 45.365756] ISV = 0, ISS = 0x00000005
[ 45.369735] CM = 0, WnR = 0
[ 45.372814] user pgtable: 4k pages, 39-bit VAs, pgdp=000000000685d000
[ 45.379663] [0000000000000008] pgd=0000000000000000, p4d=0000000000000000, pud=0000000000000000
[ 45.388856] Internal error: Oops: 96000005 [#1] SMP
[ 45.393897] Modules linked in: ath9k ath9k_common ath9k_hw
[ 45.399574] CPU: 1 PID: 309 Comm: kworker/u4:2 Not tainted 5.12.0-rc2-dirty #785
[ 45.414746] Workqueue: phy0 ath_reset_work [ath9k]
[ 45.419713] pstate: 40000005 (nZcv daif -PAN -UAO -TCO BTYPE=--)
[ 45.425910] pc : ath9k_hw_reset+0xc4/0x1c48 [ath9k_hw]
[ 45.431234] lr : ath9k_hw_reset+0xc0/0x1c48 [ath9k_hw]
[ 45.436548] sp : ffffffc0118dbca0
[ 45.439961] x29: ffffffc0118dbca0 x28: 0000000000000000
[ 45.445442] x27: ffffff800dee4080 x26: 0000000000000000
[ 45.450923] x25: ffffff800df9b9d8 x24: 0000000000000000
[ 45.456404] x23: ffffffc0115f6000 x22: ffffffc008d0d408
[ 45.461885] x21: ffffff800dee5080 x20: ffffff800df9b9d8
[ 45.467366] x19: 0000000000000000 x18: 0000000000000000
[ 45.472846] x17: 0000000000000000 x16: 0000000000000000
[ 45.478326] x15: 0000000000000010 x14: ffffffffffffffff
[ 45.483807] x13: ffffffc0918db94f x12: ffffffc011498720
[ 45.489289] x11: 0000000000000003 x10: ffffffc0114806e0
[ 45.494770] x9 : ffffffc01014b2ec x8 : 0000000000017fe8
[ 45.500251] x7 : c0000000ffffefff x6 : 0000000000000001
[ 45.505733] x5 : 0000000000000000 x4 : 0000000000000000
[ 45.511213] x3 : 0000000000000000 x2 : ffffff801fece870
[ 45.516693] x1 : ffffffc00eded000 x0 : 000000000000003f
[ 45.522174] Call trace:
[ 45.524695] ath9k_hw_reset+0xc4/0x1c48 [ath9k_hw]
[ 45.529653] ath_reset_internal+0x1a8/0x2b8 [ath9k]
[ 45.534696] ath_reset_work+0x2c/0x40 [ath9k]
[ 45.539198] process_one_work+0x210/0x480
[ 45.543339] worker_thread+0x5c/0x510
[ 45.547115] kthread+0x12c/0x130
[ 45.550445] ret_from_fork+0x10/0x1c
[ 45.554138] Code: 910922c2 9117e021 95ff0398 b4000294 (b9400a61)
[ 45.560430] ---[ end trace 566410ba90b50e8b ]---
[ 45.565193] Kernel panic - not syncing: Oops: Fatal exception in interrupt
[ 45.572282] SMP: stopping secondary CPUs
[ 45.576331] Kernel Offset: disabled
[ 45.579924] CPU features: 0x00040002,0000200c
[ 45.584416] Memory Limit: none
[ 45.587564] Rebooting in 3 seconds..
Signed-off-by: Pali Rohár <pali@kernel.org>
Cc: stable@vger.kernel.org
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20210402122653.24014-1-pali@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 08a84410a0 upstream.
Stop dmaengine transfer in sci_stop_tx(). Otherwise, the following
message is possible output when system enters suspend and while
transferring data, because clearing TIE bit in SCSCR is not able to
stop any dmaengine transfer.
sh-sci e6550000.serial: ttySC1: Unable to drain transmitter
Note that this driver has already used some #ifdef in the .c file
so that this patch also uses #ifdef to fix the issue. Otherwise,
build errors happens if the CONFIG_SERIAL_SH_SCI_DMA is disabled.
Fixes: 73a19e4c03 ("serial: sh-sci: Add DMA support.")
Cc: <stable@vger.kernel.org> # v4.9+
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Link: https://lore.kernel.org/r/20210610110806.277932-1-yoshihiro.shimoda.uh@renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 2ac0b029a0 upstream.
The regmap is configured for 8 bit registers, uses a RB-Tree cache and
marks several registers as volatile (i.e. do not cache).
The ALS and PS data registers in the chip are 16 bit wide and spans
two regmap registers. In the current driver only the base register is
marked as volatile, resulting in the upper register only read once.
Further the data sheet notes:
| When the I2C read operation starts, all four ALS data registers are
| locked until the I2C read operation of register 0x8B is completed.
Which results in the registers never update after the 2nd read.
This patch fixes the problem by marking the upper 8 bits of the ALS
and PS registers as volatile, too.
Fixes: 2f2c96338a ("iio: ltr501: Add regmap support.")
Reported-by: Oliver Lang <Oliver.Lang@gossenmetrawatt.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Tested-by: Nikita Travkin <nikita@trvn.ru> # ltr559
Link: https://lore.kernel.org/r/20210610134619.2101372-2-mkl@pengutronix.de
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 7cd04c863f upstream.
Allocating an IRQ is conditional to the IRQ existence, but freeing it
was not. If no IRQ was allocate, the driver would still try to free
IRQ 0. Add the missing checks.
This fixes the following trace when the driver is removed:
[ 100.667788] Trying to free already-free IRQ 0
[ 100.667793] WARNING: CPU: 0 PID: 2315 at kernel/irq/manage.c:1826 free_irq+0x1fd/0x370
...
[ 100.667914] Call Trace:
[ 100.667920] tcs3472_remove+0x3a/0x90 [tcs3472]
[ 100.667927] i2c_device_remove+0x2b/0xa0
Signed-off-by: frank zago <frank@zago.net>
Link: https://lore.kernel.org/r/20210427022017.19314-2-frank@zago.net
Fixes: 9d2f715d59 ("iio: light: tcs3472: support out-of-threshold events")
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit d927ccfccb upstream.
The kernel writes to swap files on f2fs directly without the assistance
of the filesystem. This direct write by kernel can be non-sequential
even when the f2fs is in LFS mode. Such non-sequential write conflicts
with the LFS semantics. Especially when f2fs is set up on zoned block
devices, the non-sequential write causes unaligned write command errors.
To avoid the non-sequential writes to swap files, prevent swap file
activation when the filesystem is in LFS mode.
Fixes: 4969c06a0d ("f2fs: support swap file w/ DIO")
Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Cc: stable@vger.kernel.org # v5.10+
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 85b18d7b5e upstream.
Turns out that the bit 61 in the TEID is not always 1 and if that's
the case the address space ID and the address are
unpredictable. Without an address and its address space ID we can't
export memory and hence we can only send a SIGSEGV to the process or
panic the kernel depending on who caused the exception.
Unfortunately bit 61 is only reliable if we have the "misc" UV feature
bit.
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Fixes: 084ea4d611 ("s390/mm: add (non)secure page access exceptions handlers")
Cc: stable@vger.kernel.org
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit c749d8c018 upstream.
Currently css_wait_for_slow_path() gets called inside the chp->lock.
The path-verification-loop of slowpath inside this lock could lead to
deadlock as reported by the lockdep validator.
The ccw_device_get_chp_desc() during the instance of a device-set-online
would try to acquire the same 'chp->lock' to read the chp->desc.
The instance of this function can get called from multiple scenario,
like probing or setting-device online manually. This could, in some
corner-cases lead to the deadlock.
lockdep validator reported this as,
CPU0 CPU1
---- ----
lock(&chp->lock);
lock(kn->active#43);
lock(&chp->lock);
lock((wq_completion)cio);
The chp->lock was introduced to serialize the access of struct
channel_path. This lock is not needed for the css_wait_for_slow_path()
function, so invoke the slow-path function outside this lock.
Fixes: b730f3a933 ("[S390] cio: add lock to struct channel_path")
Cc: <stable@vger.kernel.org>
Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Vineeth Vijayan <vneethv@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit ef318b9edf upstream.
Use the MMU's role to get its effective SMEP value when injecting a fault
into the guest. When walking L1's (nested) NPT while L2 is active, vCPU
state will reflect L2, whereas NPT uses the host's (L1 in this case) CR0,
CR4, EFER, etc... If L1 and L2 have different settings for SMEP and
L1 does not have EFER.NX=1, this can result in an incorrect PFEC.FETCH
when injecting #NPF.
Fixes: e57d4a356a ("KVM: Add instruction fetch checking when walking guest page table")
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210622175739.3610207-5-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 112022bdb5 upstream.
Mark NX as being used for all non-nested shadow MMUs, as KVM will set the
NX bit for huge SPTEs if the iTLB mutli-hit mitigation is enabled.
Checking the mitigation itself is not sufficient as it can be toggled on
at any time and KVM doesn't reset MMU contexts when that happens. KVM
could reset the contexts, but that would require purging all SPTEs in all
MMUs, for no real benefit. And, KVM already forces EFER.NX=1 when TDP is
disabled (for WP=0, SMEP=1, NX=0), so technically NX is never reserved
for shadow MMUs.
Fixes: b8e8c8303f ("kvm: mmu: ITLB_MULTIHIT mitigation")
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210622175739.3610207-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b33bb78a1f upstream.
Mark #ACs that won't be reinjected to the guest as wanted by L0 so that
KVM handles split-lock #AC from L2 instead of forwarding the exception to
L1. Split-lock #AC isn't yet virtualized, i.e. L1 will treat it like a
regular #AC and do the wrong thing, e.g. reinject it into L2.
Fixes: e6f8b6c12f ("KVM: VMX: Extend VMXs #AC interceptor to handle split lock #AC in guest")
Cc: Xiaoyao Li <xiaoyao.li@intel.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210622172244.3561540-1-seanjc@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit c24d373225 upstream.
try_grab_compound_head() is used to grab a reference to a page from
get_user_pages_fast(), which is only protected against concurrent freeing
of page tables (via local_irq_save()), but not against concurrent TLB
flushes, freeing of data pages, or splitting of compound pages.
Because no reference is held to the page when try_grab_compound_head() is
called, the page may have been freed and reallocated by the time its
refcount has been elevated; therefore, once we're holding a stable
reference to the page, the caller re-checks whether the PTE still points
to the same page (with the same access rights).
The problem is that try_grab_compound_head() has to grab a reference on
the head page; but between the time we look up what the head page is and
the time we actually grab a reference on the head page, the compound page
may have been split up (either explicitly through split_huge_page() or by
freeing the compound page to the buddy allocator and then allocating its
individual order-0 pages). If that happens, get_user_pages_fast() may end
up returning the right page but lifting the refcount on a now-unrelated
page, leading to use-after-free of pages.
To fix it: Re-check whether the pages still belong together after lifting
the refcount on the head page. Move anything else that checks
compound_head(page) below the refcount increment.
This can't actually happen on bare-metal x86 (because there, disabling
IRQs locks out remote TLB flushes), but it can happen on virtualized x86
(e.g. under KVM) and probably also on arm64. The race window is pretty
narrow, and constantly allocating and shattering hugepages isn't exactly
fast; for now I've only managed to reproduce this in an x86 KVM guest with
an artificially widened timing window (by adding a loop that repeatedly
calls `inl(0x3f8 + 5)` in `try_get_compound_head()` to force VM exits, so
that PV TLB flushes are used instead of IPIs).
As requested on the list, also replace the existing VM_BUG_ON_PAGE() with
a warning and bailout. Since the existing code only performed the BUG_ON
check on DEBUG_VM kernels, ensure that the new code also only performs the
check under that configuration - I don't want to mix two logically
separate changes together too much. The macro VM_WARN_ON_ONCE_PAGE()
doesn't return a value on !DEBUG_VM, so wrap the whole check in an #ifdef
block. An alternative would be to change the VM_WARN_ON_ONCE_PAGE()
definition for !DEBUG_VM such that it always returns false, but since that
would differ from the behavior of the normal WARN macros, it might be too
confusing for readers.
Link: https://lkml.kernel.org/r/20210615012014.1100672-1-jannh@google.com
Fixes: 7aef4172c7 ("mm: handle PTE-mapped tail pages in gerneric fast gup implementaiton")
Signed-off-by: Jann Horn <jannh@google.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Jan Kara <jack@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 02b49cd117 upstream.
During system resume, MHI host triggers M3->M0 transition and then waits
for target device to enter M0 state. Once done, the device queues a state
change event into ctrl event ring and notifies MHI host by raising an
interrupt, where a tasklet is scheduled to process this event. In most
cases, the tasklet is served timely and wait operation succeeds.
However, there are cases where CPU is busy and cannot serve this tasklet
for some time. Once delay goes long enough, the device moves itself to M1
state and also interrupts MHI host after inserting a new state change
event to ctrl ring. Later when CPU finally has time to process the ring,
there will be two events:
1. For M3->M0 event, which is the first event to be processed queued first.
The tasklet handler serves the event, updates device state to M0 and
wakes up the task.
2. For M0->M1 event, which is processed later, the tasklet handler
triggers M1->M2 transition and updates device state to M2 directly,
then wakes up the MHI host (if it is still sleeping on this wait queue).
Note that although MHI host has been woken up while processing the first
event, it may still has no chance to run before the second event is
processed. In other words, MHI host has to keep waiting till timeout
causing the M0 state to be missed.
kernel log here:
...
Apr 15 01:45:14 test-NUC8i7HVK kernel: [ 4247.911251] mhi 0000:06:00.0: Entered with PM state: M3, MHI state: M3
Apr 15 01:45:14 test-NUC8i7HVK kernel: [ 4247.917762] mhi 0000:06:00.0: State change event to state: M0
Apr 15 01:45:14 test-NUC8i7HVK kernel: [ 4247.917767] mhi 0000:06:00.0: State change event to state: M1
Apr 15 01:45:14 test-NUC8i7HVK kernel: [ 4338.788231] mhi 0000:06:00.0: Did not enter M0 state, MHI state: M2, PM state: M2
...
Fix this issue by simply adding M2 as a valid state for resume.
Tested-on: WCN6855 hw2.0 PCI WLAN.HSP.1.1-01720.1-QCAHSPSWPL_V1_V2_SILICONZ_LITE-1
Cc: stable@vger.kernel.org
Fixes: 0c6b20a1d7 ("bus: mhi: core: Add support for MHI suspend and resume")
Signed-off-by: Baochen Qiang <bqiang@codeaurora.org>
Reviewed-by: Hemant Kumar <hemantk@codeaurora.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/20210524040312.14409-1-bqiang@codeaurora.org
[mani: slightly massaged the commit message]
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/20210621161616.77524-4-manivannan.sadhasivam@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 5483b904bf upstream.
When find a task from wait queue to wake up, a non-privileged task may
be found out, rather than the privileged. This maybe lead a deadlock
same as commit dfe1fe75e0 ("NFSv4: Fix deadlock between nfs4_evict_inode()
and nfs4_opendata_get_inode()"):
Privileged delegreturn task is queued to privileged list because all
the slots are assigned. If there has no enough slot to wake up the
non-privileged batch tasks(session less than 8 slot), then the privileged
delegreturn task maybe lost waked up because the found out task can't
get slot since the session is on draining.
So we should treate the privileged task as the emergency task, and
execute it as for as we can.
Reported-by: Hulk Robot <hulkci@huawei.com>
Fixes: 5fcdfacc01 ("NFSv4: Return delegations synchronously in evict_inode")
Cc: stable@vger.kernel.org
Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit fcb170a9d8 upstream.
The 'queue->nr' will wraparound from 0 to 255 when only current
priority queue has tasks. This maybe lead a deadlock same as commit
dfe1fe75e0 ("NFSv4: Fix deadlock between nfs4_evict_inode()
and nfs4_opendata_get_inode()"):
Privileged delegreturn task is queued to privileged list because all
the slots are assigned. When non-privileged task complete and release
the slot, a non-privileged maybe picked out. It maybe allocate slot
failed when the session on draining.
If the 'queue->nr' has wraparound to 255, and no enough slot to
service it, then the privileged delegreturn will lost to wake up.
So we should avoid the wraparound on 'queue->nr'.
Reported-by: Hulk Robot <hulkci@huawei.com>
Fixes: 5fcdfacc01 ("NFSv4: Return delegations synchronously in evict_inode")
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 14a4696bc3 upstream.
When closing the isotp socket, the potentially running hrtimers are
canceled before removing the subscription for CAN identifiers via
can_rx_unregister().
This may lead to an unintended (re)start of a hrtimer in
isotp_rcv_cf() and isotp_rcv_fc() in the case that a CAN frame is
received by isotp_rcv() while the subscription removal is processed.
However, isotp_rcv() is called under RCU protection, so after calling
can_rx_unregister, we may call synchronize_rcu in order to wait for
any RCU read-side critical sections to finish. This prevents the
reception of CAN frames after hrtimer_cancel() and therefore the
unintended (re)start of the hrtimers.
Link: https://lore.kernel.org/r/20210618173713.2296-1-socketcan@hartkopp.net
Fixes: e057dd3fc2 ("can: add ISO 15765-2:2016 transport protocol")
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit d5f9023fa6 upstream.
can_rx_register() callbacks may be called concurrently to the call to
can_rx_unregister(). The callbacks and callback data, though, are
protected by RCU and the struct sock reference count.
So the callback data is really attached to the life of sk, meaning
that it should be released on sk_destruct. However, bcm_remove_op()
calls tasklet_kill(), and RCU callbacks may be called under RCU
softirq, so that cannot be used on kernels before the introduction of
HRTIMER_MODE_SOFT.
However, bcm_rx_handler() is called under RCU protection, so after
calling can_rx_unregister(), we may call synchronize_rcu() in order to
wait for any RCU read-side critical sections to finish. That is,
bcm_rx_handler() won't be called anymore for those ops. So, we only
free them, after we do that synchronize_rcu().
Fixes: ffd980f976 ("[CAN]: Add broadcast manager (bcm) protocol")
Link: https://lore.kernel.org/r/20210619161813.2098382-1-cascardo@canonical.com
Cc: linux-stable <stable@vger.kernel.org>
Reported-by: syzbot+0f7e7e5e2f4f40fa89c0@syzkaller.appspotmail.com
Reported-by: Norbert Slusarek <nslusarek@gmx.net>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
