Security Vulnerabilities
- CVEs Published In February 2024
In the Linux kernel, the following vulnerability has been resolved:
perf/core: Fix unconditional security_locked_down() call
Currently, the lockdown state is queried unconditionally, even though
its result is used only if the PERF_SAMPLE_REGS_INTR bit is set in
attr.sample_type. While that doesn't matter in case of the Lockdown LSM,
it causes trouble with the SELinux's lockdown hook implementation.
SELinux implements the locked_down hook with a check whether the current
task's type has the corresponding "lockdown" class permission
("integrity" or "confidentiality") allowed in the policy. This means
that calling the hook when the access control decision would be ignored
generates a bogus permission check and audit record.
Fix this by checking sample_type first and only calling the hook when
its result would be honored.
In the Linux kernel, the following vulnerability has been resolved:
ovl: fix leaked dentry
Since commit 6815f479ca90 ("ovl: use only uppermetacopy state in
ovl_lookup()"), overlayfs doesn't put temporary dentry when there is a
metacopy error, which leads to dentry leaks when shutting down the related
superblock:
overlayfs: refusing to follow metacopy origin for (/file0)
...
BUG: Dentry (____ptrval____){i=3f33,n=file3} still in use (1) [unmount of overlay overlay]
...
WARNING: CPU: 1 PID: 432 at umount_check.cold+0x107/0x14d
CPU: 1 PID: 432 Comm: unmount-overlay Not tainted 5.12.0-rc5 #1
...
RIP: 0010:umount_check.cold+0x107/0x14d
...
Call Trace:
d_walk+0x28c/0x950
? dentry_lru_isolate+0x2b0/0x2b0
? __kasan_slab_free+0x12/0x20
do_one_tree+0x33/0x60
shrink_dcache_for_umount+0x78/0x1d0
generic_shutdown_super+0x70/0x440
kill_anon_super+0x3e/0x70
deactivate_locked_super+0xc4/0x160
deactivate_super+0xfa/0x140
cleanup_mnt+0x22e/0x370
__cleanup_mnt+0x1a/0x30
task_work_run+0x139/0x210
do_exit+0xb0c/0x2820
? __kasan_check_read+0x1d/0x30
? find_held_lock+0x35/0x160
? lock_release+0x1b6/0x660
? mm_update_next_owner+0xa20/0xa20
? reacquire_held_locks+0x3f0/0x3f0
? __sanitizer_cov_trace_const_cmp4+0x22/0x30
do_group_exit+0x135/0x380
__do_sys_exit_group.isra.0+0x20/0x20
__x64_sys_exit_group+0x3c/0x50
do_syscall_64+0x45/0x70
entry_SYSCALL_64_after_hwframe+0x44/0xae
...
VFS: Busy inodes after unmount of overlay. Self-destruct in 5 seconds. Have a nice day...
This fix has been tested with a syzkaller reproducer.
In the Linux kernel, the following vulnerability has been resolved:
net: qrtr: Avoid potential use after free in MHI send
It is possible that the MHI ul_callback will be invoked immediately
following the queueing of the skb for transmission, leading to the
callback decrementing the refcount of the associated sk and freeing the
skb.
As such the dereference of skb and the increment of the sk refcount must
happen before the skb is queued, to avoid the skb to be used after free
and potentially the sk to drop its last refcount..
In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix masking negation logic upon negative dst register
The negation logic for the case where the off_reg is sitting in the
dst register is not correct given then we cannot just invert the add
to a sub or vice versa. As a fix, perform the final bitwise and-op
unconditionally into AX from the off_reg, then move the pointer from
the src to dst and finally use AX as the source for the original
pointer arithmetic operation such that the inversion yields a correct
result. The single non-AX mov in between is possible given constant
blinding is retaining it as it's not an immediate based operation.
The uAMQP is a C library for AMQP 1.0 communication to Azure Cloud Services. When processing an incorrect `AMQP_VALUE` failed state, may cause a double free problem. This may cause a RCE. Update submodule with commit 2ca42b6e4e098af2d17e487814a91d05f6ae4987.
In the Linux kernel, the following vulnerability has been resolved:
io_uring: fix shared sqpoll cancellation hangs
[ 736.982891] INFO: task iou-sqp-4294:4295 blocked for more than 122 seconds.
[ 736.982897] Call Trace:
[ 736.982901] schedule+0x68/0xe0
[ 736.982903] io_uring_cancel_sqpoll+0xdb/0x110
[ 736.982908] io_sqpoll_cancel_cb+0x24/0x30
[ 736.982911] io_run_task_work_head+0x28/0x50
[ 736.982913] io_sq_thread+0x4e3/0x720
We call io_uring_cancel_sqpoll() one by one for each ctx either in
sq_thread() itself or via task works, and it's intended to cancel all
requests of a specified context. However the function uses per-task
counters to track the number of inflight requests, so it counts more
requests than available via currect io_uring ctx and goes to sleep for
them to appear (e.g. from IRQ), that will never happen.
Cancel a bit more than before, i.e. all ctxs that share sqpoll
and continue to use shared counters. Don't forget that we should not
remove ctx from the list before running that task_work sqpoll-cancel,
otherwise the function wouldn't be able to find the context and will
hang.
In the Linux kernel, the following vulnerability has been resolved:
media: staging/intel-ipu3: Fix set_fmt error handling
If there in an error during a set_fmt, do not overwrite the previous
sizes with the invalid config.
Without this patch, v4l2-compliance ends up allocating 4GiB of RAM and
causing the following OOPs
[ 38.662975] ipu3-imgu 0000:00:05.0: swiotlb buffer is full (sz: 4096 bytes)
[ 38.662980] DMA: Out of SW-IOMMU space for 4096 bytes at device 0000:00:05.0
[ 38.663010] general protection fault: 0000 [#1] PREEMPT SMP
In the Linux kernel, the following vulnerability has been resolved:
media: staging/intel-ipu3: Fix memory leak in imu_fmt
We are losing the reference to an allocated memory if try. Change the
order of the check to avoid that.
In the Linux kernel, the following vulnerability has been resolved:
ext4: always panic when errors=panic is specified
Before commit 014c9caa29d3 ("ext4: make ext4_abort() use
__ext4_error()"), the following series of commands would trigger a
panic:
1. mount /dev/sda -o ro,errors=panic test
2. mount /dev/sda -o remount,abort test
After commit 014c9caa29d3, remounting a file system using the test
mount option "abort" will no longer trigger a panic. This commit will
restore the behaviour immediately before commit 014c9caa29d3.
(However, note that the Linux kernel's behavior has not been
consistent; some previous kernel versions, including 5.4 and 4.19
similarly did not panic after using the mount option "abort".)
This also makes a change to long-standing behaviour; namely, the
following series commands will now cause a panic, when previously it
did not:
1. mount /dev/sda -o ro,errors=panic test
2. echo test > /sys/fs/ext4/sda/trigger_fs_error
However, this makes ext4's behaviour much more consistent, so this is
a good thing.
In the Linux kernel, the following vulnerability has been resolved:
sfc: adjust efx->xdp_tx_queue_count with the real number of initialized queues
efx->xdp_tx_queue_count is initially initialized to num_possible_cpus() and is
later used to allocate and traverse efx->xdp_tx_queues lookup array. However,
we may end up not initializing all the array slots with real queues during
probing. This results, for example, in a NULL pointer dereference, when running
"# ethtool -S <iface>", similar to below
[2570283.664955][T4126959] BUG: kernel NULL pointer dereference, address: 00000000000000f8
[2570283.681283][T4126959] #PF: supervisor read access in kernel mode
[2570283.695678][T4126959] #PF: error_code(0x0000) - not-present page
[2570283.710013][T4126959] PGD 0 P4D 0
[2570283.721649][T4126959] Oops: 0000 [#1] SMP PTI
[2570283.734108][T4126959] CPU: 23 PID: 4126959 Comm: ethtool Tainted: G O 5.10.20-cloudflare-2021.3.1 #1
[2570283.752641][T4126959] Hardware name: <redacted>
[2570283.781408][T4126959] RIP: 0010:efx_ethtool_get_stats+0x2ca/0x330 [sfc]
[2570283.796073][T4126959] Code: 00 85 c0 74 39 48 8b 95 a8 0f 00 00 48 85 d2 74 2d 31 c0 eb 07 48 8b 95 a8 0f 00 00 48 63 c8 49 83 c4 08 83 c0 01 48 8b 14 ca <48> 8b 92 f8 00 00 00 49 89 54 24 f8 39 85 a0 0f 00 00 77 d7 48 8b
[2570283.831259][T4126959] RSP: 0018:ffffb79a77657ce8 EFLAGS: 00010202
[2570283.845121][T4126959] RAX: 0000000000000019 RBX: ffffb799cd0c9280 RCX: 0000000000000018
[2570283.860872][T4126959] RDX: 0000000000000000 RSI: ffff96dd970ce000 RDI: 0000000000000005
[2570283.876525][T4126959] RBP: ffff96dd86f0a000 R08: ffff96dd970ce480 R09: 000000000000005f
[2570283.892014][T4126959] R10: ffffb799cd0c9fff R11: ffffb799cd0c9000 R12: ffffb799cd0c94f8
[2570283.907406][T4126959] R13: ffffffffc11b1090 R14: ffff96dd970ce000 R15: ffffffffc11cd66c
[2570283.922705][T4126959] FS: 00007fa7723f8740(0000) GS:ffff96f51fac0000(0000) knlGS:0000000000000000
[2570283.938848][T4126959] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[2570283.952524][T4126959] CR2: 00000000000000f8 CR3: 0000001a73e6e006 CR4: 00000000007706e0
[2570283.967529][T4126959] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[2570283.982400][T4126959] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[2570283.997308][T4126959] PKRU: 55555554
[2570284.007649][T4126959] Call Trace:
[2570284.017598][T4126959] dev_ethtool+0x1832/0x2830
Fix this by adjusting efx->xdp_tx_queue_count after probing to reflect the true
value of initialized slots in efx->xdp_tx_queues.