Linux: >> Linux Kernel >> 6.12.90 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
btrfs: tracepoints: fix sleep while in atomic context in btrfs_sync_file()
The trace event btrfs_sync_file() is called in an atomic context (all trace
events are) and its call to dput(), which is needed due to the call to
dget_parent(), can sleep, triggering a kernel splat.
This can be reproduced by enabling the trace event and running btrfs/056
from fstests for example. The splat shown in dmesg is the following:
[53.919] BUG: sleeping function called from invalid context at fs/dcache.c:970
[53.947] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 32773, name: xfs_io
[53.988] preempt_count: 2, expected: 0
[53.967] RCU nest depth: 0, expected: 0
[53.943] Preemption disabled at:
[53.944] [<0000000000000000>] 0x0
[54.078] CPU: 0 UID: 0 PID: 32773 Comm: xfs_io Tainted: G W 7.1.0-rc1-btrfs-next-232+ #1 PREEMPT(full)
[54.070] Tainted: [W]=WARN
[54.071] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.2-0-gea1b7a073390-prebuilt.qemu.org 04/01/2014
[54.072] Call Trace:
[54.074] <TASK>
[54.076] dump_stack_lvl+0x56/0x80
[54.079] __might_resched.cold+0xd6/0x10f
[54.072] dput.part.0+0x24/0x110
[54.078] trace_event_raw_event_btrfs_sync_file+0x75/0x140 [btrfs]
[54.089] btrfs_sync_file+0x1ed/0x530 [btrfs]
[54.087] ? __handle_mm_fault+0x8ae/0xed0
[54.089] btrfs_do_write_iter+0x172/0x210 [btrfs]
[54.091] vfs_write+0x21f/0x450
[54.094] __x64_sys_pwrite64+0x8d/0xc0
[54.096] ? do_user_addr_fault+0x20c/0x670
[54.099] do_syscall_64+0x60/0xf20
[54.092] ? clear_bhb_loop+0x60/0xb0
[54.094] entry_SYSCALL_64_after_hwframe+0x76/0x7e
So stop using dget_parent() and dput() and access the parent dentry
directly as dentry->d_parent. This is also what ext4 is doing in
its equivalent trace event ext4_sync_file_enter().
CVSS Score
5.5
EPSS Score
0.001
Published
2026-07-19
In the Linux kernel, the following vulnerability has been resolved:
ARM: integrator: Fix early initialization
Starting with commit bdb249fce9ad4 ("ARM: integrator: read counter using
syscon/regmap"), intcp_init_early calls syscon_regmap_lookup_by_compatible
which in turn calls of_syscon_register. This function allocates memory.
Since the memory management code has not been initialized at that time,
the call always fails. It either returns -ENOMEM or crashes as follows.
Unable to handle kernel NULL pointer dereference at virtual address 0000000c when read
[0000000c] *pgd=00000000
Internal error: Oops: 5 [#1] ARM
Modules linked in:
CPU: 0 UID: 0 PID: 0 Comm: swapper Not tainted 6.15.0-rc5-00026-g5fcc9bf84ee5 #1 PREEMPT
Hardware name: ARM Integrator/CP (Device Tree)
PC is at __kmalloc_cache_noprof+0xec/0x39c
LR is at __kmalloc_cache_noprof+0x34/0x39c
...
Call trace:
__kmalloc_cache_noprof from of_syscon_register+0x7c/0x310
of_syscon_register from device_node_get_regmap+0xa4/0xb0
device_node_get_regmap from intcp_init_early+0xc/0x40
intcp_init_early from start_kernel+0x60/0x688
start_kernel from 0x0
The crash is seen due to a dereferenced pointer which is not supposed to be
NULL but is NULL if the memory management subsystem has not been
initialized. The crash is not seen with all versions of gcc. Some versions
such as gcc 9.x apparently do not dereference the pointer, presumably if
tracing is disabled. The problem has been reproduced with gcc 10.x, 11.x,
and 13.x. Either case, if the crash is not seen, the call to
syscon_regmap_lookup_by_compatible returns -ENOMEM, and
sched_clock_register is never called.
Fix the problem by moving the early initialization code into the standard
machine initialization code.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-07-19
In the Linux kernel, the following vulnerability has been resolved:
firmware: arm_ffa: Check for NULL FF-A ID table while driver registration
The bus match callback assumes that every FF-A driver provides an
id_table and dereferences it unconditionally. Enforce that contract at
registration time so a buggy client driver cannot crash the bus during
match.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-07-19
In the Linux kernel, the following vulnerability has been resolved:
spi: sprd: fix error pointer deref after DMA setup failure
The driver falls back to PIO mode if DMA setup fails during probe.
Make sure to check the dma.enabled flag before trying to release the DMA
channels also on late probe errors to avoid dereferencing an error
pointer (or attempting to release a channel a second time).
This issue was flagged by Sashiko when reviewing a devres allocation
conversion patch.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-07-19
In the Linux kernel, the following vulnerability has been resolved:
drm/msm: Fix iommu_map_sgtable() return value check and avoid WARN
Commit "iommu: return full error code from iommu_map_sg[_atomic]()"
changed iommu_map_sgtable() to return an ssize_t and negative values
in error cases, rather than a size_t and a zero.
Store the return value in the appropriate type and in case of error,
return it rather than WARNing.
Patchwork: https://patchwork.freedesktop.org/patch/719685/
CVSS Score
8.8
EPSS Score
0.001
Published
2026-07-19
In the Linux kernel, the following vulnerability has been resolved:
drm/msm/adreno: Fix a reference leak in a6xx_gpu_init()
In a6xx_gpu_init(), node is obtained via of_parse_phandle().
While there was a manual of_node_put() at the end of the
common path, several early error returns would bypass this call,
resulting in a reference leak.
Fix this by using the __free(device_node) cleanup handler to
release the reference when the variable goes out of scope.
Patchwork: https://patchwork.freedesktop.org/patch/700661/
CVSS Score
5.5
EPSS Score
0.002
Published
2026-07-19
In the Linux kernel, the following vulnerability has been resolved:
wifi: ath11k: fix error path leaks in some WMI WOW calls
Fix two instances where we used to directly return the result of
ath11k_wmi_cmd_send(...). Because we did not check the return value, we
also did not free the skb in the error path.
CVSS Score
5.5
EPSS Score
0.002
Published
2026-07-19
In the Linux kernel, the following vulnerability has been resolved:
netfs: Fix partial invalidation of streaming-write folio
In netfs_invalidate_folio(), if the region of a partial invalidation
overlaps the front (but not all) of a dirty write cached in a streaming
write page (dirty, but not uptodate, with the dirty region tracked by a
netfs_folio struct), the function modifies the dirty region - but
incorrectly as it moves the region forward by setting the start to the
start, not the end, of the invalidation region.
Fix this by setting finfo->dirty_offset to the end of the invalidation
region (iend).
CVSS Score
5.5
EPSS Score
0.002
Published
2026-07-19
In the Linux kernel, the following vulnerability has been resolved:
netfs: Fix write streaming disablement if fd open O_RDWR
In netfs_perform_write(), "write streaming" (the caching of dirty data in
dirty but !uptodate folios) is performed to avoid the need to read data
that is just going to get immediately overwritten. However, this is/will
be disabled in three circumstances: if the fd is open O_RDWR, if fscache is
in use (as we need to round out the blocks for DIO) or if content
encryption is enabled (again for rounding out purposes).
The idea behind disabling it if the fd is open O_RDWR is that we'd need to
flush the write-streaming page before we could read the data, particularly
through mmap. But netfs now fills in the gaps if ->read_folio() is called
on the page, so that is unnecessary. Further, this doesn't actually work
if a separate fd is open for reading.
Fix this by removing the check for O_RDWR, thereby allowing streaming
writes even when we might read.
This caused a number of problems with the generic/522 xfstest, but those
are now fixed.
CVSS Score
7.3
EPSS Score
0.001
Published
2026-07-19
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: close durable scavenger races against m_fp_list lookups
ksmbd_durable_scavenger() has two related races against any walker
that iterates f_ci->m_fp_list, including ksmbd_lookup_fd_inode()
(used by ksmbd_vfs_rename) and the share-mode checks in
fs/smb/server/smb_common.c.
(1) fp->node list-head reuse. Durable-preserved handles can remain
linked on f_ci->m_fp_list after session teardown so share-mode checks
still see them while the handle is reconnectable. The scavenger
collected expired handles by adding fp->node to a local
scavenger_list after removing them from the global durable idr.
Because fp->node is the same list_head used by m_fp_list,
list_add(&fp->node, &scavenger_list) overwrites the m_fp_list links
and corrupts both lists. CONFIG_DEBUG_LIST can report this on the
share-mode walk path.
(2) Refcount race against m_fp_list walkers. The scavenger qualifies
an expired durable handle with atomic_read(&fp->refcount) > 1 and
fp->conn under global_ft.lock, removes fp from global_ft, then drops
global_ft.lock before unlinking fp from m_fp_list and freeing it.
During that gap fp is still linked on m_fp_list with f_state ==
FP_INITED. ksmbd_lookup_fd_inode() under m_lock read calls
ksmbd_fp_get() (atomic_inc_not_zero on refcount that is still 1) and
takes a live reference; the scavenger then unlinks and frees fp
while the holder owns a reference, leading to UAF on the holder's
subsequent ksmbd_fd_put() and on any field reads performed by a
concurrent share-mode walker that iterates m_fp_list without taking
ksmbd_fp_get() (smb_check_perm_dleases-like paths).
Fix both:
* Stop reusing fp->node as a scavenger-private list node. Remove
one expired handle from global_ft under global_ft.lock, take an
explicit transient reference, drop the lock, unlink fp->node
from m_fp_list under f_ci->m_lock, then drop both the durable
lifetime and transient references with atomic_sub_and_test(2,
&fp->refcount). If the scavenger is the last putter the close
runs there; otherwise an in-flight holder that already raced
through the m_fp_list lookup owns the final close via its
ksmbd_fd_put() path. The one-at-a-time disposal can rescan the
durable idr when multiple handles expire in the same pass, but
durable scavenging is a background expiration path and the final
full scan recomputes min_timeout before the next wait.
* Clear fp->persistent_id inside __ksmbd_remove_durable_fd() right
after idr_remove(), so a delayed final close from a holder that
snatched fp does not re-issue idr_remove() on a persistent id
that idr_alloc_cyclic() in ksmbd_open_durable_fd() may have
already handed out to a brand-new durable handle.
* Bypass the per-conn open_files_count decrement in
__put_fd_final() when fp is detached from any session table
(fp->conn cleared by session_fd_check() at durable preserve --
paired with the volatile_id clear at unpublish, so checking
fp->conn alone is sufficient). The walker that owns the final
close runs from an unrelated work->conn whose
stats.open_files_count never tracked this durable fp; without
this guard the holder would underflow that unrelated counter.
The two races are folded into one patch because patch (1) alone
cleans up the corrupted list but leaves a deterministic UAF window
for m_fp_list walkers that the transient-reference and
persistent_id discipline in (2) close; bisecting onto an
intermediate state would land on a UAF that pre-patch chaos merely
made less reproducible.
Validation:
* CONFIG_DEBUG_LIST coverage for the list_head reuse path.
* KASAN-enabled direct SMB2 durable-handle coverage that exercised
ksmbd_durable_scavenger() and non-NULL ksmbd_lookup_fd_inode()
returns while durable handles expired under concurrent rename
lookups, with no KASAN, UAF, list-corruption, ODEBUG, or WARNING
reports.
---truncated---
CVSS Score
9.8
EPSS Score
0.005
Published
2026-07-19