Linux: >> Linux Kernel >> 6.13.4 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
phonet/pep: disable BH around forwarded sk_receive_skb()
The networking receive path is usually run from softirq context, but
protocols that take the socket lock may have packets stored in the
backlog and processed later from process context. In that case
release_sock() -> __release_sock() drops the slock with spin_unlock_bh()
and then calls sk->sk_backlog_rcv() with bottom halves enabled.
Typical sk_backlog_rcv handlers process the socket whose backlog is
being drained, so the BH state at entry is irrelevant for the slocks
they touch. pep_do_rcv() is different: when the inbound skb targets an
existing PEP pipe, it forwards the skb to a different *child* socket
via sk_receive_skb(). That helper takes the child slock with
bh_lock_sock_nested(), which is just spin_lock_nested() and assumes BH
is already off. The same child slock therefore ends up acquired with
BH on (process path) and with BH off (softirq path):
process context softirq context
--------------- ---------------
release_sock(listener) __netif_receive_skb()
__release_sock() phonet_rcv()
spin_unlock_bh() __sk_receive_skb(listener)
[BH now ENABLED] [BH already disabled]
sk_backlog_rcv: sk_backlog_rcv:
pep_do_rcv() pep_do_rcv()
sk_receive_skb(child) sk_receive_skb(child)
bh_lock_sock_nested(child) bh_lock_sock_nested(child)
=> SOFTIRQ-ON-W => IN-SOFTIRQ-W
Lockdep flags this as inconsistent lock state, and it can become a real
self-deadlock if a softirq on the same CPU tries to receive to the same
child socket while its slock is held in the BH-enabled path:
WARNING: inconsistent lock state
inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.
(slock-AF_PHONET/1){+.?.}-{3:3}, at: __sk_receive_skb+0x1cf/0x900
__sk_receive_skb net/core/sock.c:563
sk_receive_skb include/net/sock.h:2022 [inline]
pep_do_rcv net/phonet/pep.c:675
sk_backlog_rcv include/net/sock.h:1190
__release_sock net/core/sock.c:3216
release_sock net/core/sock.c:3815
pep_sock_accept net/phonet/pep.c:879
Wrap the forwarded sk_receive_skb() in local_bh_disable() /
local_bh_enable() so the child slock is always acquired with BH off.
local_bh_disable() nests safely on the softirq path.
Discovered via in-house syzkaller fuzzing; the same root cause also
on the linux-6.1.y syzbot dashboard as extid 44f0626dd6284f02663c.
Reproduced under KASAN + LOCKDEP + PROVE_LOCKING, reproducer:
https://pastebin.com/A3t8xzCR
CVSS Score
5.5
EPSS Score
0.001
Published
2026-07-19
In the Linux kernel, the following vulnerability has been resolved:
test_kprobes: clear kprobes between test runs
Running the kprobes sanity tests twice makes all tests fail and
eventually crashes the kernel.
[root@martin-riscv-1 ~]# echo 1 > /sys/kernel/debug/kunit/kprobes_test/run
...
# Totals: pass:5 fail:0 skip:0 total:5
ok 1 kprobes_test
[root@martin-riscv-1 ~]# echo 1 > /sys/kernel/debug/kunit/kprobes_test/run
...
# test_kprobe: EXPECTATION FAILED at lib/tests/test_kprobes.c:64
Expected 0 == register_kprobe(&kp), but
register_kprobe(&kp) == -22 (0xffffffffffffffea)
...
Unable to handle kernel paging request ...
The testsuite defines several kprobes and kretprobes as static variables
that are preserved across test runs.
After register_kprobe and unregister_kprobe, a kprobe contains some
leftover data that must be cleared before the kprobe can be registered
again. The tests are setting symbol_name to define the probe location.
Address and flags must be cleared.
The existing code clears some of the probes between subsequent tests, but
not between two test runs. The leftover data from a previous test run
makes the registrations fail in the next run.
Move the cleanups for all kprobes into kprobes_test_init, this function
is called before each single test (including the first test of a test
run).
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