commit 8750e72a79 upstream.
Fetching an index for any vcpu in kvm->vcpus array by traversing
the entire array everytime is costly.
This patch remembers the position of each vcpu in kvm->vcpus array
by storing it in vcpus_idx under kvm_vcpu structure.
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Nitesh Narayan Lal <nitesh@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[borntraeger@de.ibm.com]: backport to 4.19 (also fits for 5.4)
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit c7c5e6ff53 ]
syzbot found that forcing a big quantum attribute would crash hosts fast,
essentially using this:
tc qd replace dev eth0 root fq_codel quantum 4294967295
This is because fq_codel_dequeue() would have to loop
~2^31 times in :
if (flow->deficit <= 0) {
flow->deficit += q->quantum;
list_move_tail(&flow->flowchain, &q->old_flows);
goto begin;
}
SFQ max quantum is 2^19 (half a megabyte)
Lets adopt a max quantum of one megabyte for FQ_CODEL.
Fixes: 4b549a2ef4 ("fq_codel: Fair Queue Codel AQM")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 04f08eb44b upstream.
syzbot reported another data-race in af_unix [1]
Lets change __skb_insert() to use WRITE_ONCE() when changing
skb head qlen.
Also, change unix_dgram_poll() to use lockless version
of unix_recvq_full()
It is verry possible we can switch all/most unix_recvq_full()
to the lockless version, this will be done in a future kernel version.
[1] HEAD commit: 8596e589b7
BUG: KCSAN: data-race in skb_queue_tail / unix_dgram_poll
write to 0xffff88814eeb24e0 of 4 bytes by task 25815 on cpu 0:
__skb_insert include/linux/skbuff.h:1938 [inline]
__skb_queue_before include/linux/skbuff.h:2043 [inline]
__skb_queue_tail include/linux/skbuff.h:2076 [inline]
skb_queue_tail+0x80/0xa0 net/core/skbuff.c:3264
unix_dgram_sendmsg+0xff2/0x1600 net/unix/af_unix.c:1850
sock_sendmsg_nosec net/socket.c:703 [inline]
sock_sendmsg net/socket.c:723 [inline]
____sys_sendmsg+0x360/0x4d0 net/socket.c:2392
___sys_sendmsg net/socket.c:2446 [inline]
__sys_sendmmsg+0x315/0x4b0 net/socket.c:2532
__do_sys_sendmmsg net/socket.c:2561 [inline]
__se_sys_sendmmsg net/socket.c:2558 [inline]
__x64_sys_sendmmsg+0x53/0x60 net/socket.c:2558
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
read to 0xffff88814eeb24e0 of 4 bytes by task 25834 on cpu 1:
skb_queue_len include/linux/skbuff.h:1869 [inline]
unix_recvq_full net/unix/af_unix.c:194 [inline]
unix_dgram_poll+0x2bc/0x3e0 net/unix/af_unix.c:2777
sock_poll+0x23e/0x260 net/socket.c:1288
vfs_poll include/linux/poll.h:90 [inline]
ep_item_poll fs/eventpoll.c:846 [inline]
ep_send_events fs/eventpoll.c:1683 [inline]
ep_poll fs/eventpoll.c:1798 [inline]
do_epoll_wait+0x6ad/0xf00 fs/eventpoll.c:2226
__do_sys_epoll_wait fs/eventpoll.c:2238 [inline]
__se_sys_epoll_wait fs/eventpoll.c:2233 [inline]
__x64_sys_epoll_wait+0xf6/0x120 fs/eventpoll.c:2233
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
value changed: 0x0000001b -> 0x00000001
Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 25834 Comm: syz-executor.1 Tainted: G W 5.14.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Fixes: 86b18aaa2b ("skbuff: fix a data race in skb_queue_len()")
Cc: Qian Cai <cai@lca.pw>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit d7aff291d0 ]
Oxford Semiconductor 950 serial port devices have a 128-byte FIFO and in
the enhanced (650) mode, which we select in `autoconfig_has_efr' with
the ECB bit set in the EFR register, they support the receive interrupt
trigger level selectable with FCR bits 7:6 from the set of 16, 32, 112,
120. This applies to the original OX16C950 discrete UART[1] as well as
950 cores embedded into more complex devices.
For these devices we set the default to 112, which sets an excessively
high level of 112 or 7/8 of the FIFO capacity, unlike with other port
types where we choose at most 1/2 of their respective FIFO capacities.
Additionally we don't make the trigger level configurable. Consequently
frequent input overruns happen with high bit rates where hardware flow
control cannot be used (e.g. terminal applications) even with otherwise
highly-performant systems.
Lower the default receive interrupt trigger level to 32 then, and make
it configurable. Document the trigger levels along with other port
types, including the set of 16, 32, 64, 112 for the transmit interrupt
as well[2].
References:
[1] "OX16C950 rev B High Performance UART with 128 byte FIFOs", Oxford
Semiconductor, Inc., DS-0031, Sep 05, Table 10: "Receiver Trigger
Levels", p. 22
[2] same, Table 9: "Transmit Interrupt Trigger Levels", p. 22
Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Link: https://lore.kernel.org/r/alpine.DEB.2.21.2106260608480.37803@angie.orcam.me.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit e042aa532c upstream.
In 7fedb63a83 ("bpf: Tighten speculative pointer arithmetic mask") we
narrowed the offset mask for unprivileged pointer arithmetic in order to
mitigate a corner case where in the speculative domain it is possible to
advance, for example, the map value pointer by up to value_size-1 out-of-
bounds in order to leak kernel memory via side-channel to user space.
The verifier's state pruning for scalars leaves one corner case open
where in the first verification path R_x holds an unknown scalar with an
aux->alu_limit of e.g. 7, and in a second verification path that same
register R_x, here denoted as R_x', holds an unknown scalar which has
tighter bounds and would thus satisfy range_within(R_x, R_x') as well as
tnum_in(R_x, R_x') for state pruning, yielding an aux->alu_limit of 3:
Given the second path fits the register constraints for pruning, the final
generated mask from aux->alu_limit will remain at 7. While technically
not wrong for the non-speculative domain, it would however be possible
to craft similar cases where the mask would be too wide as in 7fedb63a83.
One way to fix it is to detect the presence of unknown scalar map pointer
arithmetic and force a deeper search on unknown scalars to ensure that
we do not run into a masking mismatch.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
[OP: adjusted context for 4.19]
Signed-off-by: Ovidiu Panait <ovidiu.panait@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 2039f26f3a upstream.
Spectre v4 gadgets make use of memory disambiguation, which is a set of
techniques that execute memory access instructions, that is, loads and
stores, out of program order; Intel's optimization manual, section 2.4.4.5:
A load instruction micro-op may depend on a preceding store. Many
microarchitectures block loads until all preceding store addresses are
known. The memory disambiguator predicts which loads will not depend on
any previous stores. When the disambiguator predicts that a load does
not have such a dependency, the load takes its data from the L1 data
cache. Eventually, the prediction is verified. If an actual conflict is
detected, the load and all succeeding instructions are re-executed.
af86ca4e30 ("bpf: Prevent memory disambiguation attack") tried to mitigate
this attack by sanitizing the memory locations through preemptive "fast"
(low latency) stores of zero prior to the actual "slow" (high latency) store
of a pointer value such that upon dependency misprediction the CPU then
speculatively executes the load of the pointer value and retrieves the zero
value instead of the attacker controlled scalar value previously stored at
that location, meaning, subsequent access in the speculative domain is then
redirected to the "zero page".
The sanitized preemptive store of zero prior to the actual "slow" store is
done through a simple ST instruction based on r10 (frame pointer) with
relative offset to the stack location that the verifier has been tracking
on the original used register for STX, which does not have to be r10. Thus,
there are no memory dependencies for this store, since it's only using r10
and immediate constant of zero; hence af86ca4e30 /assumed/ a low latency
operation.
However, a recent attack demonstrated that this mitigation is not sufficient
since the preemptive store of zero could also be turned into a "slow" store
and is thus bypassed as well:
[...]
// r2 = oob address (e.g. scalar)
// r7 = pointer to map value
31: (7b) *(u64 *)(r10 -16) = r2
// r9 will remain "fast" register, r10 will become "slow" register below
32: (bf) r9 = r10
// JIT maps BPF reg to x86 reg:
// r9 -> r15 (callee saved)
// r10 -> rbp
// train store forward prediction to break dependency link between both r9
// and r10 by evicting them from the predictor's LRU table.
33: (61) r0 = *(u32 *)(r7 +24576)
34: (63) *(u32 *)(r7 +29696) = r0
35: (61) r0 = *(u32 *)(r7 +24580)
36: (63) *(u32 *)(r7 +29700) = r0
37: (61) r0 = *(u32 *)(r7 +24584)
38: (63) *(u32 *)(r7 +29704) = r0
39: (61) r0 = *(u32 *)(r7 +24588)
40: (63) *(u32 *)(r7 +29708) = r0
[...]
543: (61) r0 = *(u32 *)(r7 +25596)
544: (63) *(u32 *)(r7 +30716) = r0
// prepare call to bpf_ringbuf_output() helper. the latter will cause rbp
// to spill to stack memory while r13/r14/r15 (all callee saved regs) remain
// in hardware registers. rbp becomes slow due to push/pop latency. below is
// disasm of bpf_ringbuf_output() helper for better visual context:
//
// ffffffff8117ee20: 41 54 push r12
// ffffffff8117ee22: 55 push rbp
// ffffffff8117ee23: 53 push rbx
// ffffffff8117ee24: 48 f7 c1 fc ff ff ff test rcx,0xfffffffffffffffc
// ffffffff8117ee2b: 0f 85 af 00 00 00 jne ffffffff8117eee0 <-- jump taken
// [...]
// ffffffff8117eee0: 49 c7 c4 ea ff ff ff mov r12,0xffffffffffffffea
// ffffffff8117eee7: 5b pop rbx
// ffffffff8117eee8: 5d pop rbp
// ffffffff8117eee9: 4c 89 e0 mov rax,r12
// ffffffff8117eeec: 41 5c pop r12
// ffffffff8117eeee: c3 ret
545: (18) r1 = map[id:4]
547: (bf) r2 = r7
548: (b7) r3 = 0
549: (b7) r4 = 4
550: (85) call bpf_ringbuf_output#194288
// instruction 551 inserted by verifier \
551: (7a) *(u64 *)(r10 -16) = 0 | /both/ are now slow stores here
// storing map value pointer r7 at fp-16 | since value of r10 is "slow".
552: (7b) *(u64 *)(r10 -16) = r7 /
// following "fast" read to the same memory location, but due to dependency
// misprediction it will speculatively execute before insn 551/552 completes.
553: (79) r2 = *(u64 *)(r9 -16)
// in speculative domain contains attacker controlled r2. in non-speculative
// domain this contains r7, and thus accesses r7 +0 below.
554: (71) r3 = *(u8 *)(r2 +0)
// leak r3
As can be seen, the current speculative store bypass mitigation which the
verifier inserts at line 551 is insufficient since /both/, the write of
the zero sanitation as well as the map value pointer are a high latency
instruction due to prior memory access via push/pop of r10 (rbp) in contrast
to the low latency read in line 553 as r9 (r15) which stays in hardware
registers. Thus, architecturally, fp-16 is r7, however, microarchitecturally,
fp-16 can still be r2.
Initial thoughts to address this issue was to track spilled pointer loads
from stack and enforce their load via LDX through r10 as well so that /both/
the preemptive store of zero /as well as/ the load use the /same/ register
such that a dependency is created between the store and load. However, this
option is not sufficient either since it can be bypassed as well under
speculation. An updated attack with pointer spill/fills now _all_ based on
r10 would look as follows:
[...]
// r2 = oob address (e.g. scalar)
// r7 = pointer to map value
[...]
// longer store forward prediction training sequence than before.
2062: (61) r0 = *(u32 *)(r7 +25588)
2063: (63) *(u32 *)(r7 +30708) = r0
2064: (61) r0 = *(u32 *)(r7 +25592)
2065: (63) *(u32 *)(r7 +30712) = r0
2066: (61) r0 = *(u32 *)(r7 +25596)
2067: (63) *(u32 *)(r7 +30716) = r0
// store the speculative load address (scalar) this time after the store
// forward prediction training.
2068: (7b) *(u64 *)(r10 -16) = r2
// preoccupy the CPU store port by running sequence of dummy stores.
2069: (63) *(u32 *)(r7 +29696) = r0
2070: (63) *(u32 *)(r7 +29700) = r0
2071: (63) *(u32 *)(r7 +29704) = r0
2072: (63) *(u32 *)(r7 +29708) = r0
2073: (63) *(u32 *)(r7 +29712) = r0
2074: (63) *(u32 *)(r7 +29716) = r0
2075: (63) *(u32 *)(r7 +29720) = r0
2076: (63) *(u32 *)(r7 +29724) = r0
2077: (63) *(u32 *)(r7 +29728) = r0
2078: (63) *(u32 *)(r7 +29732) = r0
2079: (63) *(u32 *)(r7 +29736) = r0
2080: (63) *(u32 *)(r7 +29740) = r0
2081: (63) *(u32 *)(r7 +29744) = r0
2082: (63) *(u32 *)(r7 +29748) = r0
2083: (63) *(u32 *)(r7 +29752) = r0
2084: (63) *(u32 *)(r7 +29756) = r0
2085: (63) *(u32 *)(r7 +29760) = r0
2086: (63) *(u32 *)(r7 +29764) = r0
2087: (63) *(u32 *)(r7 +29768) = r0
2088: (63) *(u32 *)(r7 +29772) = r0
2089: (63) *(u32 *)(r7 +29776) = r0
2090: (63) *(u32 *)(r7 +29780) = r0
2091: (63) *(u32 *)(r7 +29784) = r0
2092: (63) *(u32 *)(r7 +29788) = r0
2093: (63) *(u32 *)(r7 +29792) = r0
2094: (63) *(u32 *)(r7 +29796) = r0
2095: (63) *(u32 *)(r7 +29800) = r0
2096: (63) *(u32 *)(r7 +29804) = r0
2097: (63) *(u32 *)(r7 +29808) = r0
2098: (63) *(u32 *)(r7 +29812) = r0
// overwrite scalar with dummy pointer; same as before, also including the
// sanitation store with 0 from the current mitigation by the verifier.
2099: (7a) *(u64 *)(r10 -16) = 0 | /both/ are now slow stores here
2100: (7b) *(u64 *)(r10 -16) = r7 | since store unit is still busy.
// load from stack intended to bypass stores.
2101: (79) r2 = *(u64 *)(r10 -16)
2102: (71) r3 = *(u8 *)(r2 +0)
// leak r3
[...]
Looking at the CPU microarchitecture, the scheduler might issue loads (such
as seen in line 2101) before stores (line 2099,2100) because the load execution
units become available while the store execution unit is still busy with the
sequence of dummy stores (line 2069-2098). And so the load may use the prior
stored scalar from r2 at address r10 -16 for speculation. The updated attack
may work less reliable on CPU microarchitectures where loads and stores share
execution resources.
This concludes that the sanitizing with zero stores from af86ca4e30 ("bpf:
Prevent memory disambiguation attack") is insufficient. Moreover, the detection
of stack reuse from af86ca4e30 where previously data (STACK_MISC) has been
written to a given stack slot where a pointer value is now to be stored does
not have sufficient coverage as precondition for the mitigation either; for
several reasons outlined as follows:
1) Stack content from prior program runs could still be preserved and is
therefore not "random", best example is to split a speculative store
bypass attack between tail calls, program A would prepare and store the
oob address at a given stack slot and then tail call into program B which
does the "slow" store of a pointer to the stack with subsequent "fast"
read. From program B PoV such stack slot type is STACK_INVALID, and
therefore also must be subject to mitigation.
2) The STACK_SPILL must not be coupled to register_is_const(&stack->spilled_ptr)
condition, for example, the previous content of that memory location could
also be a pointer to map or map value. Without the fix, a speculative
store bypass is not mitigated in such precondition and can then lead to
a type confusion in the speculative domain leaking kernel memory near
these pointer types.
While brainstorming on various alternative mitigation possibilities, we also
stumbled upon a retrospective from Chrome developers [0]:
[...] For variant 4, we implemented a mitigation to zero the unused memory
of the heap prior to allocation, which cost about 1% when done concurrently
and 4% for scavenging. Variant 4 defeats everything we could think of. We
explored more mitigations for variant 4 but the threat proved to be more
pervasive and dangerous than we anticipated. For example, stack slots used
by the register allocator in the optimizing compiler could be subject to
type confusion, leading to pointer crafting. Mitigating type confusion for
stack slots alone would have required a complete redesign of the backend of
the optimizing compiler, perhaps man years of work, without a guarantee of
completeness. [...]
>From BPF side, the problem space is reduced, however, options are rather
limited. One idea that has been explored was to xor-obfuscate pointer spills
to the BPF stack:
[...]
// preoccupy the CPU store port by running sequence of dummy stores.
[...]
2106: (63) *(u32 *)(r7 +29796) = r0
2107: (63) *(u32 *)(r7 +29800) = r0
2108: (63) *(u32 *)(r7 +29804) = r0
2109: (63) *(u32 *)(r7 +29808) = r0
2110: (63) *(u32 *)(r7 +29812) = r0
// overwrite scalar with dummy pointer; xored with random 'secret' value
// of 943576462 before store ...
2111: (b4) w11 = 943576462
2112: (af) r11 ^= r7
2113: (7b) *(u64 *)(r10 -16) = r11
2114: (79) r11 = *(u64 *)(r10 -16)
2115: (b4) w2 = 943576462
2116: (af) r2 ^= r11
// ... and restored with the same 'secret' value with the help of AX reg.
2117: (71) r3 = *(u8 *)(r2 +0)
[...]
While the above would not prevent speculation, it would make data leakage
infeasible by directing it to random locations. In order to be effective
and prevent type confusion under speculation, such random secret would have
to be regenerated for each store. The additional complexity involved for a
tracking mechanism that prevents jumps such that restoring spilled pointers
would not get corrupted is not worth the gain for unprivileged. Hence, the
fix in here eventually opted for emitting a non-public BPF_ST | BPF_NOSPEC
instruction which the x86 JIT translates into a lfence opcode. Inserting the
latter in between the store and load instruction is one of the mitigations
options [1]. The x86 instruction manual notes:
[...] An LFENCE that follows an instruction that stores to memory might
complete before the data being stored have become globally visible. [...]
The latter meaning that the preceding store instruction finished execution
and the store is at minimum guaranteed to be in the CPU's store queue, but
it's not guaranteed to be in that CPU's L1 cache at that point (globally
visible). The latter would only be guaranteed via sfence. So the load which
is guaranteed to execute after the lfence for that local CPU would have to
rely on store-to-load forwarding. [2], in section 2.3 on store buffers says:
[...] For every store operation that is added to the ROB, an entry is
allocated in the store buffer. This entry requires both the virtual and
physical address of the target. Only if there is no free entry in the store
buffer, the frontend stalls until there is an empty slot available in the
store buffer again. Otherwise, the CPU can immediately continue adding
subsequent instructions to the ROB and execute them out of order. On Intel
CPUs, the store buffer has up to 56 entries. [...]
One small upside on the fix is that it lifts constraints from af86ca4e30
where the sanitize_stack_off relative to r10 must be the same when coming
from different paths. The BPF_ST | BPF_NOSPEC gets emitted after a BPF_STX
or BPF_ST instruction. This happens either when we store a pointer or data
value to the BPF stack for the first time, or upon later pointer spills.
The former needs to be enforced since otherwise stale stack data could be
leaked under speculation as outlined earlier. For non-x86 JITs the BPF_ST |
BPF_NOSPEC mapping is currently optimized away, but others could emit a
speculation barrier as well if necessary. For real-world unprivileged
programs e.g. generated by LLVM, pointer spill/fill is only generated upon
register pressure and LLVM only tries to do that for pointers which are not
used often. The program main impact will be the initial BPF_ST | BPF_NOSPEC
sanitation for the STACK_INVALID case when the first write to a stack slot
occurs e.g. upon map lookup. In future we might refine ways to mitigate
the latter cost.
[0] https://arxiv.org/pdf/1902.05178.pdf
[1] https://msrc-blog.microsoft.com/2018/05/21/analysis-and-mitigation-of-speculative-store-bypass-cve-2018-3639/
[2] https://arxiv.org/pdf/1905.05725.pdf
Fixes: af86ca4e30 ("bpf: Prevent memory disambiguation attack")
Fixes: f7cf25b202 ("bpf: track spill/fill of constants")
Co-developed-by: Piotr Krysiuk <piotras@gmail.com>
Co-developed-by: Benedict Schlueter <benedict.schlueter@rub.de>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Piotr Krysiuk <piotras@gmail.com>
Signed-off-by: Benedict Schlueter <benedict.schlueter@rub.de>
Acked-by: Alexei Starovoitov <ast@kernel.org>
[OP: - apply check_stack_write_fixed_off() changes in check_stack_write()
- replace env->bypass_spec_v4 -> env->allow_ptr_leaks]
Signed-off-by: Ovidiu Panait <ovidiu.panait@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit f5e81d1117 upstream.
In case of JITs, each of the JIT backends compiles the BPF nospec instruction
/either/ to a machine instruction which emits a speculation barrier /or/ to
/no/ machine instruction in case the underlying architecture is not affected
by Speculative Store Bypass or has different mitigations in place already.
This covers both x86 and (implicitly) arm64: In case of x86, we use 'lfence'
instruction for mitigation. In case of arm64, we rely on the firmware mitigation
as controlled via the ssbd kernel parameter. Whenever the mitigation is enabled,
it works for all of the kernel code with no need to provide any additional
instructions here (hence only comment in arm64 JIT). Other archs can follow
as needed. The BPF nospec instruction is specifically targeting Spectre v4
since i) we don't use a serialization barrier for the Spectre v1 case, and
ii) mitigation instructions for v1 and v4 might be different on some archs.
The BPF nospec is required for a future commit, where the BPF verifier does
annotate intermediate BPF programs with speculation barriers.
Co-developed-by: Piotr Krysiuk <piotras@gmail.com>
Co-developed-by: Benedict Schlueter <benedict.schlueter@rub.de>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Piotr Krysiuk <piotras@gmail.com>
Signed-off-by: Benedict Schlueter <benedict.schlueter@rub.de>
Acked-by: Alexei Starovoitov <ast@kernel.org>
[OP: adjusted context for 4.19, drop riscv and ppc32 changes]
Signed-off-by: Ovidiu Panait <ovidiu.panait@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 679c782de1 upstream.
By giving each register its own liveness chain, we elide the skip_callee()
logic. Instead, each register's parent is the state it inherits from;
both check_func_call() and prepare_func_exit() automatically connect
reg states to the correct chain since when they copy the reg state across
(r1-r5 into the callee as args, and r0 out as the return value) they also
copy the parent pointer.
Signed-off-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
[OP: adjusted context for 4.19]
Signed-off-by: Ovidiu Panait <ovidiu.panait@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit d187605605 upstream.
Add a helper function fscrypt_symlink_getattr() which will be called
from the various filesystems' ->getattr() methods to read and decrypt
the target of encrypted symlinks in order to report the correct st_size.
Detailed explanation:
As required by POSIX and as documented in various man pages, st_size for
a symlink is supposed to be the length of the symlink target.
Unfortunately, st_size has always been wrong for encrypted symlinks
because st_size is populated from i_size from disk, which intentionally
contains the length of the encrypted symlink target. That's slightly
greater than the length of the decrypted symlink target (which is the
symlink target that userspace usually sees), and usually won't match the
length of the no-key encoded symlink target either.
This hadn't been fixed yet because reporting the correct st_size would
require reading the symlink target from disk and decrypting or encoding
it, which historically has been considered too heavyweight to do in
->getattr(). Also historically, the wrong st_size had only broken a
test (LTP lstat03) and there were no known complaints from real users.
(This is probably because the st_size of symlinks isn't used too often,
and when it is, typically it's for a hint for what buffer size to pass
to readlink() -- which a slightly-too-large size still works for.)
However, a couple things have changed now. First, there have recently
been complaints about the current behavior from real users:
- Breakage in rpmbuild:
https://github.com/rpm-software-management/rpm/issues/1682https://github.com/google/fscrypt/issues/305
- Breakage in toybox cpio:
https://www.mail-archive.com/toybox@lists.landley.net/msg07193.html
- Breakage in libgit2: https://issuetracker.google.com/issues/189629152
(on Android public issue tracker, requires login)
Second, we now cache decrypted symlink targets in ->i_link. Therefore,
taking the performance hit of reading and decrypting the symlink target
in ->getattr() wouldn't be as big a deal as it used to be, since usually
it will just save having to do the same thing later.
Also note that eCryptfs ended up having to read and decrypt symlink
targets in ->getattr() as well, to fix this same issue; see
commit 3a60a1686f ("eCryptfs: Decrypt symlink target for stat size").
So, let's just bite the bullet, and read and decrypt the symlink target
in ->getattr() in order to report the correct st_size. Add a function
fscrypt_symlink_getattr() which the filesystems will call to do this.
(Alternatively, we could store the decrypted size of symlinks on-disk.
But there isn't a great place to do so, and encryption is meant to hide
the original size to some extent; that property would be lost.)
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20210702065350.209646-2-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 83dd59a0b9 upstream.
RPC server procedures are normally expected to return a __be32 encoded
status value of type 'enum rpc_accept_stat', however at least one function
wants to return an authentication status of type 'enum rpc_auth_stat'
in the case where authentication fails.
This patch adds functionality to allow this.
Fixes: a4e187d83d ("NFS: Don't drop CB requests with invalid principals")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit d0efb16294 upstream.
A common implementation of isatty(3) involves calling a ioctl passing
a dummy struct argument and checking whether the syscall failed --
bionic and glibc use TCGETS (passing a struct termios), and musl uses
TIOCGWINSZ (passing a struct winsize). If the FD is a socket, we will
copy sizeof(struct ifreq) bytes of data from the argument and return
-EFAULT if that fails. The result is that the isatty implementations
may return a non-POSIX-compliant value in errno in the case where part
of the dummy struct argument is inaccessible, as both struct termios
and struct winsize are smaller than struct ifreq (at least on arm64).
Although there is usually enough stack space following the argument
on the stack that this did not present a practical problem up to now,
with MTE stack instrumentation it's more likely for the copy to fail,
as the memory following the struct may have a different tag.
Fix the problem by adding an early check for whether the ioctl is a
valid socket ioctl, and return -ENOTTY if it isn't.
Fixes: 44c02a2c3d ("dev_ioctl(): move copyin/copyout to callers")
Link: https://linux-review.googlesource.com/id/I869da6cf6daabc3e4b7b82ac979683ba05e27d4d
Signed-off-by: Peter Collingbourne <pcc@google.com>
Cc: <stable@vger.kernel.org> # 4.19
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit e88b2c6e5a upstream.
While reviewing a different fix, John and I noticed an oddity in one of the
BPF program dumps that stood out, for example:
# bpftool p d x i 13
0: (b7) r0 = 808464450
1: (b4) w4 = 808464432
2: (bc) w0 = w0
3: (15) if r0 == 0x0 goto pc+1
4: (9c) w4 %= w0
[...]
In line 2 we noticed that the mov32 would 32 bit truncate the original src
register for the div/mod operation. While for the two operations the dst
register is typically marked unknown e.g. from adjust_scalar_min_max_vals()
the src register is not, and thus verifier keeps tracking original bounds,
simplified:
0: R1=ctx(id=0,off=0,imm=0) R10=fp0
0: (b7) r0 = -1
1: R0_w=invP-1 R1=ctx(id=0,off=0,imm=0) R10=fp0
1: (b7) r1 = -1
2: R0_w=invP-1 R1_w=invP-1 R10=fp0
2: (3c) w0 /= w1
3: R0_w=invP(id=0,umax_value=4294967295,var_off=(0x0; 0xffffffff)) R1_w=invP-1 R10=fp0
3: (77) r1 >>= 32
4: R0_w=invP(id=0,umax_value=4294967295,var_off=(0x0; 0xffffffff)) R1_w=invP4294967295 R10=fp0
4: (bf) r0 = r1
5: R0_w=invP4294967295 R1_w=invP4294967295 R10=fp0
5: (95) exit
processed 6 insns (limit 1000000) max_states_per_insn 0 total_states 0 peak_states 0 mark_read 0
Runtime result of r0 at exit is 0 instead of expected -1. Remove the
verifier mov32 src rewrite in div/mod and replace it with a jmp32 test
instead. After the fix, we result in the following code generation when
having dividend r1 and divisor r6:
div, 64 bit: div, 32 bit:
0: (b7) r6 = 8 0: (b7) r6 = 8
1: (b7) r1 = 8 1: (b7) r1 = 8
2: (55) if r6 != 0x0 goto pc+2 2: (56) if w6 != 0x0 goto pc+2
3: (ac) w1 ^= w1 3: (ac) w1 ^= w1
4: (05) goto pc+1 4: (05) goto pc+1
5: (3f) r1 /= r6 5: (3c) w1 /= w6
6: (b7) r0 = 0 6: (b7) r0 = 0
7: (95) exit 7: (95) exit
mod, 64 bit: mod, 32 bit:
0: (b7) r6 = 8 0: (b7) r6 = 8
1: (b7) r1 = 8 1: (b7) r1 = 8
2: (15) if r6 == 0x0 goto pc+1 2: (16) if w6 == 0x0 goto pc+1
3: (9f) r1 %= r6 3: (9c) w1 %= w6
4: (b7) r0 = 0 4: (b7) r0 = 0
5: (95) exit 5: (95) exit
x86 in particular can throw a 'divide error' exception for div
instruction not only for divisor being zero, but also for the case
when the quotient is too large for the designated register. For the
edx:eax and rdx:rax dividend pair it is not an issue in x86 BPF JIT
since we always zero edx (rdx). Hence really the only protection
needed is against divisor being zero.
Fixes: 68fda450a7 ("bpf: fix 32-bit divide by zero")
Co-developed-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
[Salvatore Bonaccorso: This is an earlier version of the patch provided
by Daniel Borkmann which does not rely on availability of the BPF_JMP32
instruction class. This means it is not even strictly a backport of the
upstream commit mentioned but based on Daniel's and John's work to
address the issue.]
Tested-by: Salvatore Bonaccorso <carnil@debian.org>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 848378812e upstream.
A recent change in LLVM causes module_{c,d}tor sections to appear when
CONFIG_K{A,C}SAN are enabled, which results in orphan section warnings
because these are not handled anywhere:
ld.lld: warning: arch/x86/pci/built-in.a(legacy.o):(.text.asan.module_ctor) is being placed in '.text.asan.module_ctor'
ld.lld: warning: arch/x86/pci/built-in.a(legacy.o):(.text.asan.module_dtor) is being placed in '.text.asan.module_dtor'
ld.lld: warning: arch/x86/pci/built-in.a(legacy.o):(.text.tsan.module_ctor) is being placed in '.text.tsan.module_ctor'
Fangrui explains: "the function asan.module_ctor has the SHF_GNU_RETAIN
flag, so it is in a separate section even with -fno-function-sections
(default)".
Place them in the TEXT_TEXT section so that these technologies continue
to work with the newer compiler versions. All of the KASAN and KCSAN
KUnit tests continue to pass after this change.
Cc: stable@vger.kernel.org
Link: https://github.com/ClangBuiltLinux/linux/issues/1432
Link: 7b78956224
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Fangrui Song <maskray@google.com>
Acked-by: Marco Elver <elver@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210731023107.1932981-1-nathan@kernel.org
[nc: Resolve conflict due to lack of cf68fffb66]
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 77e89afc25 upstream.
Multi-MSI uses a single MSI descriptor and there is a single mask register
when the device supports per vector masking. To avoid reading back the mask
register the value is cached in the MSI descriptor and updates are done by
clearing and setting bits in the cache and writing it to the device.
But nothing protects msi_desc::masked and the mask register from being
modified concurrently on two different CPUs for two different Linux
interrupts which belong to the same multi-MSI descriptor.
Add a lock to struct device and protect any operation on the mask and the
mask register with it.
This makes the update of msi_desc::masked unconditional, but there is no
place which requires a modification of the hardware register without
updating the masked cache.
msi_mask_irq() is now an empty wrapper which will be cleaned up in follow
up changes.
The problem goes way back to the initial support of multi-MSI, but picking
the commit which introduced the mask cache is a valid cut off point
(2.6.30).
Fixes: f2440d9acb ("PCI MSI: Refactor interrupt masking code")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20210729222542.726833414@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 826da77129 upstream.
X86 IO/APIC and MSI interrupts (when used without interrupts remapping)
require that the affinity setup on startup is done before the interrupt is
enabled for the first time as the non-remapped operation mode cannot safely
migrate enabled interrupts from arbitrary contexts. Provide a new irq chip
flag which allows affected hardware to request this.
This has to be opt-in because there have been reports in the past that some
interrupt chips cannot handle affinity setting before startup.
Fixes: 1840475676 ("genirq: Expose default irq affinity mask (take 3)")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20210729222542.779791738@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit bf88fef0b6 upstream.
The HNP work can be re-scheduled while it's still in-fly. This results in
re-initialization of the busy work, resetting the hrtimer's list node of
the work and crashing kernel with null dereference within kernel/timer
once work's timer is expired. It's very easy to trigger this problem by
re-plugging USB cable quickly. Initialize HNP work only once to fix this
trouble.
Unable to handle kernel NULL pointer dereference at virtual address 00000126)
...
PC is at __run_timers.part.0+0x150/0x228
LR is at __next_timer_interrupt+0x51/0x9c
...
(__run_timers.part.0) from [<c0187a2b>] (run_timer_softirq+0x2f/0x50)
(run_timer_softirq) from [<c01013ad>] (__do_softirq+0xd5/0x2f0)
(__do_softirq) from [<c012589b>] (irq_exit+0xab/0xb8)
(irq_exit) from [<c0170341>] (handle_domain_irq+0x45/0x60)
(handle_domain_irq) from [<c04c4a43>] (gic_handle_irq+0x6b/0x7c)
(gic_handle_irq) from [<c0100b65>] (__irq_svc+0x65/0xac)
Cc: stable@vger.kernel.org
Acked-by: Peter Chen <peter.chen@kernel.org>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Link: https://lore.kernel.org/r/20210717182134.30262-6-digetx@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit e04480920d ]
syzbot is hitting might_sleep() warning at hci_sock_dev_event() due to
calling lock_sock() with rw spinlock held [1].
It seems that history of this locking problem is a trial and error.
Commit b40df5743e ("[PATCH] bluetooth: fix socket locking in
hci_sock_dev_event()") in 2.6.21-rc4 changed bh_lock_sock() to
lock_sock() as an attempt to fix lockdep warning.
Then, commit 4ce61d1c7a ("[BLUETOOTH]: Fix locking in
hci_sock_dev_event().") in 2.6.22-rc2 changed lock_sock() to
local_bh_disable() + bh_lock_sock_nested() as an attempt to fix the
sleep in atomic context warning.
Then, commit 4b5dd696f8 ("Bluetooth: Remove local_bh_disable() from
hci_sock.c") in 3.3-rc1 removed local_bh_disable().
Then, commit e305509e67 ("Bluetooth: use correct lock to prevent UAF
of hdev object") in 5.13-rc5 again changed bh_lock_sock_nested() to
lock_sock() as an attempt to fix CVE-2021-3573.
This difficulty comes from current implementation that
hci_sock_dev_event(HCI_DEV_UNREG) is responsible for dropping all
references from sockets because hci_unregister_dev() immediately
reclaims resources as soon as returning from
hci_sock_dev_event(HCI_DEV_UNREG).
But the history suggests that hci_sock_dev_event(HCI_DEV_UNREG) was not
doing what it should do.
Therefore, instead of trying to detach sockets from device, let's accept
not detaching sockets from device at hci_sock_dev_event(HCI_DEV_UNREG),
by moving actual cleanup of resources from hci_unregister_dev() to
hci_cleanup_dev() which is called by bt_host_release() when all
references to this unregistered device (which is a kobject) are gone.
Since hci_sock_dev_event(HCI_DEV_UNREG) no longer resets
hci_pi(sk)->hdev, we need to check whether this device was unregistered
and return an error based on HCI_UNREGISTER flag. There might be subtle
behavioral difference in "monitor the hdev" functionality; please report
if you found something went wrong due to this patch.
Link: https://syzkaller.appspot.com/bug?extid=a5df189917e79d5e59c9 [1]
Reported-by: syzbot <syzbot+a5df189917e79d5e59c9@syzkaller.appspotmail.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Fixes: e305509e67 ("Bluetooth: use correct lock to prevent UAF of hdev object")
Acked-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 4039146777 ]
The patch fixing the returned value of ip6_skb_dst_mtu (int -> unsigned
int) was rebased between its initial review and the version applied. In
the meantime fade56410c was applied, which added a new variable (int)
used as the returned value. This lead to a mismatch between the function
prototype and the variable used as the return value.
Fixes: 40fc3054b4 ("net: ipv6: fix return value of ip6_skb_dst_mtu")
Cc: Vadim Fedorenko <vfedorenko@novek.ru>
Signed-off-by: Antoine Tenart <atenart@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 3c2214b602 upstream.
Removing the pcrypt module triggers this:
general protection fault, probably for non-canonical
address 0xdead000000000122
CPU: 5 PID: 264 Comm: modprobe Not tainted 5.6.0+ #2
Hardware name: QEMU Standard PC
RIP: 0010:__cpuhp_state_remove_instance+0xcc/0x120
Call Trace:
padata_sysfs_release+0x74/0xce
kobject_put+0x81/0xd0
padata_free+0x12/0x20
pcrypt_exit+0x43/0x8ee [pcrypt]
padata instances wrongly use the same hlist node for the online and dead
states, so __padata_free()'s second cpuhp remove call chokes on the node
that the first poisoned.
cpuhp multi-instance callbacks only walk forward in cpuhp_step->list and
the same node is linked in both the online and dead lists, so the list
corruption that results from padata_alloc() adding the node to a second
list without removing it from the first doesn't cause problems as long
as no instances are freed.
Avoid the issue by giving each state its own node.
Fixes: 894c9ef978 ("padata: validate cpumask without removed CPU during offline")
Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: linux-crypto@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: stable@vger.kernel.org # v5.4+
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 894c9ef978 upstream.
Configuring an instance's parallel mask without any online CPUs...
echo 2 > /sys/kernel/pcrypt/pencrypt/parallel_cpumask
echo 0 > /sys/devices/system/cpu/cpu1/online
...makes tcrypt mode=215 crash like this:
divide error: 0000 [#1] SMP PTI
CPU: 4 PID: 283 Comm: modprobe Not tainted 5.4.0-rc8-padata-doc-v2+ #2
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20191013_105130-anatol 04/01/2014
RIP: 0010:padata_do_parallel+0x114/0x300
Call Trace:
pcrypt_aead_encrypt+0xc0/0xd0 [pcrypt]
crypto_aead_encrypt+0x1f/0x30
do_mult_aead_op+0x4e/0xdf [tcrypt]
test_mb_aead_speed.constprop.0.cold+0x226/0x564 [tcrypt]
do_test+0x28c2/0x4d49 [tcrypt]
tcrypt_mod_init+0x55/0x1000 [tcrypt]
...
cpumask_weight() in padata_cpu_hash() returns 0 because the mask has no
CPUs. The problem is __padata_remove_cpu() checks for valid masks too
early and so doesn't mark the instance PADATA_INVALID as expected, which
would have made padata_do_parallel() return error before doing the
division.
Fix by introducing a second padata CPU hotplug state before
CPUHP_BRINGUP_CPU so that __padata_remove_cpu() sees the online mask
without @cpu. No need for the second argument to padata_replace() since
@cpu is now already missing from the online mask.
Fixes: 33e5445068 ("padata: Handle empty padata cpumasks")
Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Eric Biggers <ebiggers@kernel.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-crypto@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 6bd87eec23 ]
Cache a copy of the name for the life time of the backing_dev_info
structure so that we can reference it even after unregistering.
Fixes: 68f23b8906 ("memcg: fix a crash in wb_workfn when a device disappears")
Reported-by: Yufen Yu <yuyufen@huawei.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit eb7ae5e06b ]
bdi_dev_name is not a fast path function, move it out of line. This
prepares for using it from modular callers without having to export
an implementation detail like bdi_unknown_name.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 6549c46af8 ]
For linear regulators, the n_voltages should be (max - min) / step + 1.
Buck voltage from 1v to 3V, per step 100mV, and vout mask is 0x1f.
If value is from 20 to 31, the voltage will all be fixed to 3V.
And LDO also, just vout range is different from 1.2v to 3v, step is the
same. If value is from 18 to 31, the voltage will also be fixed to 3v.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Reviewed-by: ChiYuan Huang <cy_huang@richtek.com>
Link: https://lore.kernel.org/r/20210627080418.1718127-1-axel.lin@ingics.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit c7c9d2102c ]
Syzbot reported skb_over_panic() in llc_pdu_init_as_xid_cmd(). The
problem was in wrong LCC header manipulations.
Syzbot's reproducer tries to send XID packet. llc_ui_sendmsg() is
doing following steps:
1. skb allocation with size = len + header size
len is passed from userpace and header size
is 3 since addr->sllc_xid is set.
2. skb_reserve() for header_len = 3
3. filling all other space with memcpy_from_msg()
Ok, at this moment we have fully loaded skb, only headers needs to be
filled.
Then code comes to llc_sap_action_send_xid_c(). This function pushes 3
bytes for LLC PDU header and initializes it. Then comes
llc_pdu_init_as_xid_cmd(). It initalizes next 3 bytes *AFTER* LLC PDU
header and call skb_push(skb, 3). This looks wrong for 2 reasons:
1. Bytes rigth after LLC header are user data, so this function
was overwriting payload.
2. skb_push(skb, 3) call can cause skb_over_panic() since
all free space was filled in llc_ui_sendmsg(). (This can
happen is user passed 686 len: 686 + 14 (eth header) + 3 (LLC
header) = 703. SKB_DATA_ALIGN(703) = 704)
So, in this patch I added 2 new private constansts: LLC_PDU_TYPE_U_XID
and LLC_PDU_LEN_U_XID. LLC_PDU_LEN_U_XID is used to correctly reserve
header size to handle LLC + XID case. LLC_PDU_TYPE_U_XID is used by
llc_pdu_header_init() function to push 6 bytes instead of 3. And finally
I removed skb_push() call from llc_pdu_init_as_xid_cmd().
This changes should not affect other parts of LLC, since after
all steps we just transmit buffer.
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Reported-and-tested-by: syzbot+5e5a981ad7cc54c4b2b4@syzkaller.appspotmail.com
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 38ec4944b5 upstream.
After commit 0f6925b3e8 ("virtio_net: Do not pull payload in skb->head")
Guenter Roeck reported one failure in his tests using sh architecture.
After much debugging, we have been able to spot silent unaligned accesses
in inet_gro_receive()
The issue at hand is that upper networking stacks assume their header
is word-aligned. Low level drivers are supposed to reserve NET_IP_ALIGN
bytes before the Ethernet header to make that happen.
This patch hardens skb_gro_reset_offset() to not allow frag0 fast-path
if the fragment is not properly aligned.
Some arches like x86, arm64 and powerpc do not care and define NET_IP_ALIGN
as 0, this extra check will be a NOP for them.
Note that if frag0 is not used, GRO will call pskb_may_pull()
as many times as needed to pull network and transport headers.
Fixes: 0f6925b3e8 ("virtio_net: Do not pull payload in skb->head")
Fixes: 78a478d0ef ("gro: Inline skb_gro_header and cache frag0 virtual address")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Guenter Roeck <linux@roeck-us.net>
Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 0f6925b3e8 upstream.
Xuan Zhuo reported that commit 3226b158e6 ("net: avoid 32 x truesize
under-estimation for tiny skbs") brought a ~10% performance drop.
The reason for the performance drop was that GRO was forced
to chain sk_buff (using skb_shinfo(skb)->frag_list), which
uses more memory but also cause packet consumers to go over
a lot of overhead handling all the tiny skbs.
It turns out that virtio_net page_to_skb() has a wrong strategy :
It allocates skbs with GOOD_COPY_LEN (128) bytes in skb->head, then
copies 128 bytes from the page, before feeding the packet to GRO stack.
This was suboptimal before commit 3226b158e6 ("net: avoid 32 x truesize
under-estimation for tiny skbs") because GRO was using 2 frags per MSS,
meaning we were not packing MSS with 100% efficiency.
Fix is to pull only the ethernet header in page_to_skb()
Then, we change virtio_net_hdr_to_skb() to pull the missing
headers, instead of assuming they were already pulled by callers.
This fixes the performance regression, but could also allow virtio_net
to accept packets with more than 128bytes of headers.
Many thanks to Xuan Zhuo for his report, and his tests/help.
Fixes: 3226b158e6 ("net: avoid 32 x truesize under-estimation for tiny skbs")
Reported-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Link: https://www.spinics.net/lists/netdev/msg731397.html
Co-Developed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: virtualization@lists.linux-foundation.org
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 1d11fa231c ]
The doc draft-stewart-tsvwg-sctp-ipv4-00 that restricts 198 addresses
was never published. These addresses as private addresses should be
allowed to use in SCTP.
As Michael Tuexen suggested, this patch is to move 198 addresses from
unusable to private scope.
Reported-by: Sérgio <surkamp@gmail.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 0dbffbb533 ]
sk_ll_usec is read locklessly from sk_can_busy_loop()
while another thread can change its value in sock_setsockopt()
This is correct but needs annotations.
BUG: KCSAN: data-race in __skb_try_recv_datagram / sock_setsockopt
write to 0xffff88814eb5f904 of 4 bytes by task 14011 on cpu 0:
sock_setsockopt+0x1287/0x2090 net/core/sock.c:1175
__sys_setsockopt+0x14f/0x200 net/socket.c:2100
__do_sys_setsockopt net/socket.c:2115 [inline]
__se_sys_setsockopt net/socket.c:2112 [inline]
__x64_sys_setsockopt+0x62/0x70 net/socket.c:2112
do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
entry_SYSCALL_64_after_hwframe+0x44/0xae
read to 0xffff88814eb5f904 of 4 bytes by task 14001 on cpu 1:
sk_can_busy_loop include/net/busy_poll.h:41 [inline]
__skb_try_recv_datagram+0x14f/0x320 net/core/datagram.c:273
unix_dgram_recvmsg+0x14c/0x870 net/unix/af_unix.c:2101
unix_seqpacket_recvmsg+0x5a/0x70 net/unix/af_unix.c:2067
____sys_recvmsg+0x15d/0x310 include/linux/uio.h:244
___sys_recvmsg net/socket.c:2598 [inline]
do_recvmmsg+0x35c/0x9f0 net/socket.c:2692
__sys_recvmmsg net/socket.c:2771 [inline]
__do_sys_recvmmsg net/socket.c:2794 [inline]
__se_sys_recvmmsg net/socket.c:2787 [inline]
__x64_sys_recvmmsg+0xcf/0x150 net/socket.c:2787
do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
entry_SYSCALL_64_after_hwframe+0x44/0xae
value changed: 0x00000000 -> 0x00000101
Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 14001 Comm: syz-executor.3 Not tainted 5.13.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit f4e65870e5 upstream.
We need this functionality for the io_uring file registration, but
we cannot rely on it since CONFIG_UNIX can be modular. Move the helpers
to a separate file, that's always builtin to the kernel if CONFIG_UNIX is
m/y.
No functional changes in this patch, just moving code around.
Reviewed-by: Hannes Reinecke <hare@suse.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
[ backported to older kernels to get access to unix_gc_lock - gregkh ]
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 3abab27c32 upstream.
drm: Return -ENOTTY for non-drm ioctls
Return -ENOTTY from drm_ioctl() when userspace passes in a cmd number
which doesn't relate to the drm subsystem.
Glibc uses the TCGETS ioctl to implement isatty(), and without this
change isatty() returns it incorrectly returns true for drm devices.
To test run this command:
$ if [ -t 0 ]; then echo is a tty; fi < /dev/dri/card0
which shows "is a tty" without this patch.
This may also modify memory which the userspace application is not
expecting.
Signed-off-by: Charles Baylis <cb-kernel@fishzet.co.uk>
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/YPG3IBlzaMhfPqCr@stando.fishzet.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 67a9c94317 upstream.
skb_tunnel_info() returns pointer of lwtstate->data as ip_tunnel_info
type without validation. lwtstate->data can have various types such as
mpls_iptunnel_encap, etc and these are not compatible.
So skb_tunnel_info() should validate before returning that pointer.
Splat looks like:
BUG: KASAN: slab-out-of-bounds in vxlan_get_route+0x418/0x4b0 [vxlan]
Read of size 2 at addr ffff888106ec2698 by task ping/811
CPU: 1 PID: 811 Comm: ping Not tainted 5.13.0+ #1195
Call Trace:
dump_stack_lvl+0x56/0x7b
print_address_description.constprop.8.cold.13+0x13/0x2ee
? vxlan_get_route+0x418/0x4b0 [vxlan]
? vxlan_get_route+0x418/0x4b0 [vxlan]
kasan_report.cold.14+0x83/0xdf
? vxlan_get_route+0x418/0x4b0 [vxlan]
vxlan_get_route+0x418/0x4b0 [vxlan]
[ ... ]
vxlan_xmit_one+0x148b/0x32b0 [vxlan]
[ ... ]
vxlan_xmit+0x25c5/0x4780 [vxlan]
[ ... ]
dev_hard_start_xmit+0x1ae/0x6e0
__dev_queue_xmit+0x1f39/0x31a0
[ ... ]
neigh_xmit+0x2f9/0x940
mpls_xmit+0x911/0x1600 [mpls_iptunnel]
lwtunnel_xmit+0x18f/0x450
ip_finish_output2+0x867/0x2040
[ ... ]
Fixes: 61adedf3e3 ("route: move lwtunnel state to dst_entry")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 40fc3054b4 upstream.
Commit 628a5c5618 ("[INET]: Add IP(V6)_PMTUDISC_RPOBE") introduced
ip6_skb_dst_mtu with return value of signed int which is inconsistent
with actually returned values. Also 2 users of this function actually
assign its value to unsigned int variable and only __xfrm6_output
assigns result of this function to signed variable but actually uses
as unsigned in further comparisons and calls. Change this function
to return unsigned int value.
Fixes: 628a5c5618 ("[INET]: Add IP(V6)_PMTUDISC_RPOBE")
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Vadim Fedorenko <vfedorenko@novek.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit e97bc66377 ]
If a file has already been closed, then it should not be selected to
support further I/O.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
[Trond: Fix an invalid pointer deref reported by Colin Ian King]
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit ec29d0ac29 ]
If we haven't done a unbind target call we can race where
iscsi_conn_teardown wakes up the EH thread and then frees the conn while
those threads are still accessing the conn ehwait.
We can only do one TMF per session so this just moves the TMF fields from
the conn to the session. We can then rely on the
iscsi_session_teardown->iscsi_remove_session->__iscsi_unbind_session call
to remove the target and it's devices, and know after that point there is
no device or scsi-ml callout trying to access the session.
Link: https://lore.kernel.org/r/20210525181821.7617-14-michael.christie@oracle.com
Reviewed-by: Lee Duncan <lduncan@suse.com>
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 0a7790be18 upstream.
The saa6588_ioctl() function expects to get called from other kernel
functions with a 'saa6588_command' pointer, but I found nothing stops it
from getting called from user space instead, which seems rather dangerous.
The same thing happens in the davinci vpbe driver with its VENC_GET_FLD
command.
As a quick fix, add a separate .command() callback pointer for this
driver and change the two callers over to that. This change can easily
get backported to stable kernels if necessary, but since there are only
two drivers, we may want to eventually replace this with a set of more
specialized callbacks in the long run.
Fixes: c3fda7f835 ("V4L/DVB (10537): saa6588: convert to v4l2_subdev.")
Cc: stable@vger.kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit f1c74a6c07 upstream.
Trying to get the AB8500 charging driver working I ran into a bit
of bitrot: we haven't used the driver for a while so errors in
refactorings won't be noticed.
This one is pretty self evident: use argument to the macro or we
end up with a random pointer to something else.
Cc: stable@vger.kernel.org
Cc: Krzysztof Kozlowski <krzk@kernel.org>
Cc: Marcus Cooper <codekipper@gmail.com>
Fixes: 297d716f62 ("power_supply: Change ownership from driver to core")
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 0c5dc070ff ]
Ilja reported that, simply putting it, nothing was validating that
from_addr_param functions were operating on initialized memory. That is,
the parameter itself was being validated by sctp_walk_params, but it
doesn't check for types and their specific sizes and it could be a 0-length
one, causing from_addr_param to potentially work over the next parameter or
even uninitialized memory.
The fix here is to, in all calls to from_addr_param, check if enough space
is there for the wanted IP address type.
Reported-by: Ilja Van Sprundel <ivansprundel@ioactive.com>
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 2d8ea148e5 ]
Th_strings arrays netdev_features_strings, tunable_strings, and
phy_tunable_strings has been moved to file net/ethtool/common.c.
So fixes the comment.
Signed-off-by: Jian Shen <shenjian15@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
