Linux: >> Linux Kernel >> 5.15.191 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
net: ncsi: fix skb leak in error paths
Early return paths in NCSI RX and AEN handlers fail to release
the received skb, resulting in a memory leak.
Specifically, ncsi_aen_handler() returns on invalid AEN packets
without consuming the skb. Similarly, ncsi_rcv_rsp() exits early
when failing to resolve the NCSI device, response handler, or
request, leaving the skb unfreed.
CVSS Score
7.5
EPSS Score
0.005
Published
2026-05-08
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: Don't log keys in SMB3 signing and encryption key generation
When KSMBD_DEBUG_AUTH logging is enabled, generate_smb3signingkey() and
generate_smb3encryptionkey() log the session, signing, encryption, and
decryption key bytes. Remove the logs to avoid exposing credentials.
CVSS Score
8.1
EPSS Score
0.002
Published
2026-05-08
In the Linux kernel, the following vulnerability has been resolved:
smb: server: fix use-after-free in smb2_open()
The opinfo pointer obtained via rcu_dereference(fp->f_opinfo) is
dereferenced after rcu_read_unlock(), creating a use-after-free
window.
CVSS Score
9.8
EPSS Score
0.003
Published
2026-05-08
In the Linux kernel, the following vulnerability has been resolved:
smb: client: fix in-place encryption corruption in SMB2_write()
SMB2_write() places write payload in iov[1..n] as part of rq_iov.
smb3_init_transform_rq() pointer-shares rq_iov, so crypt_message()
encrypts iov[1] in-place, replacing the original plaintext with
ciphertext. On a replayable error, the retry sends the same iov[1]
which now contains ciphertext instead of the original data,
resulting in corruption.
The corruption is most likely to be observed when connections are
unstable, as reconnects trigger write retries that re-send the
already-encrypted data.
This affects SFU mknod, MF symlinks, etc. On kernels before
6.10 (prior to the netfs conversion), sync writes also used
this path and were similarly affected. The async write path
wasn't unaffected as it uses rq_iter which gets deep-copied.
Fix by moving the write payload into rq_iter via iov_iter_kvec(),
so smb3_init_transform_rq() deep-copies it before encryption.
CVSS Score
8.1
EPSS Score
0.002
Published
2026-05-08
In the Linux kernel, the following vulnerability has been resolved:
x86/apic: Disable x2apic on resume if the kernel expects so
When resuming from s2ram, firmware may re-enable x2apic mode, which may have
been disabled by the kernel during boot either because it doesn't support IRQ
remapping or for other reasons. This causes the kernel to continue using the
xapic interface, while the hardware is in x2apic mode, which causes hangs.
This happens on defconfig + bare metal + s2ram.
Fix this in lapic_resume() by disabling x2apic if the kernel expects it to be
disabled, i.e. when x2apic_mode = 0.
The ACPI v6.6 spec, Section 16.3 [1] says firmware restores either the
pre-sleep configuration or initial boot configuration for each CPU, including
MSR state:
When executing from the power-on reset vector as a result of waking from an
S2 or S3 sleep state, the platform firmware performs only the hardware
initialization required to restore the system to either the state the
platform was in prior to the initial operating system boot, or to the
pre-sleep configuration state. In multiprocessor systems, non-boot
processors should be placed in the same state as prior to the initial
operating system boot.
(further ahead)
If this is an S2 or S3 wake, then the platform runtime firmware restores
minimum context of the system before jumping to the waking vector. This
includes:
CPU configuration. Platform runtime firmware restores the pre-sleep
configuration or initial boot configuration of each CPU (MSR, MTRR,
firmware update, SMBase, and so on). Interrupts must be disabled (for
IA-32 processors, disabled by CLI instruction).
(and other things)
So at least as per the spec, re-enablement of x2apic by the firmware is
allowed if "x2apic on" is a part of the initial boot configuration.
[1] https://uefi.org/specs/ACPI/6.6/16_Waking_and_Sleeping.html#initialization
[ bp: Massage. ]
CVSS Score
5.5
EPSS Score
0.001
Published
2026-05-08
In the Linux kernel, the following vulnerability has been resolved:
xfs: fix undersized l_iclog_roundoff values
If the superblock doesn't list a log stripe unit, we set the incore log
roundoff value to 512. This leads to corrupt logs and unmountable
filesystems in generic/617 on a disk with 4k physical sectors...
XFS (sda1): Mounting V5 Filesystem ff3121ca-26e6-4b77-b742-aaff9a449e1c
XFS (sda1): Torn write (CRC failure) detected at log block 0x318e. Truncating head block from 0x3197.
XFS (sda1): failed to locate log tail
XFS (sda1): log mount/recovery failed: error -74
XFS (sda1): log mount failed
XFS (sda1): Mounting V5 Filesystem ff3121ca-26e6-4b77-b742-aaff9a449e1c
XFS (sda1): Ending clean mount
...on the current xfsprogs for-next which has a broken mkfs. xfs_info
shows this...
meta-data=/dev/sda1 isize=512 agcount=4, agsize=644992 blks
= sectsz=4096 attr=2, projid32bit=1
= crc=1 finobt=1, sparse=1, rmapbt=1
= reflink=1 bigtime=1 inobtcount=1 nrext64=1
= exchange=1 metadir=1
data = bsize=4096 blocks=2579968, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0, ftype=1, parent=1
log =internal log bsize=4096 blocks=16384, version=2
= sectsz=4096 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
= rgcount=0 rgsize=268435456 extents
= zoned=0 start=0 reserved=0
...observe that the log section has sectsz=4096 sunit=0, which means
that the roundoff factor is 512, not 4096 as you'd expect. We should
fix mkfs not to generate broken filesystems, but anyone can fuzz the
ondisk superblock so we should be more cautious. I think the inadequate
logic predates commit a6a65fef5ef8d0, but that's clearly going to
require a different backport.
CVSS Score
8.2
EPSS Score
0.004
Published
2026-05-08
In the Linux kernel, the following vulnerability has been resolved:
i3c: mipi-i3c-hci: Fix race in DMA ring dequeue
The HCI DMA dequeue path (hci_dma_dequeue_xfer()) may be invoked for
multiple transfers that timeout around the same time. However, the
function is not serialized and can race with itself.
When a timeout occurs, hci_dma_dequeue_xfer() stops the ring, processes
incomplete transfers, and then restarts the ring. If another timeout
triggers a parallel call into the same function, the two instances may
interfere with each other - stopping or restarting the ring at unexpected
times.
Add a mutex so that hci_dma_dequeue_xfer() is serialized with respect to
itself.
CVSS Score
7.8
EPSS Score
0.001
Published
2026-05-08
In the Linux kernel, the following vulnerability has been resolved:
iio: light: bh1780: fix PM runtime leak on error path
Move pm_runtime_put_autosuspend() before the error check to ensure
the PM runtime reference count is always decremented after
pm_runtime_get_sync(), regardless of whether the read operation
succeeds or fails.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-05-08
In the Linux kernel, the following vulnerability has been resolved:
iio: gyro: mpu3050-core: fix pm_runtime error handling
The return value of pm_runtime_get_sync() is not checked, allowing
the driver to access hardware that may fail to resume. The device
usage count is also unconditionally incremented. Use
pm_runtime_resume_and_get() which propagates errors and avoids
incrementing the usage count on failure.
In preenable, add pm_runtime_put_autosuspend() on set_8khz_samplerate()
failure since postdisable does not run when preenable fails.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-05-08
In the Linux kernel, the following vulnerability has been resolved:
btrfs: fix transaction abort on set received ioctl due to item overflow
If the set received ioctl fails due to an item overflow when attempting to
add the BTRFS_UUID_KEY_RECEIVED_SUBVOL we have to abort the transaction
since we did some metadata updates before.
This means that if a user calls this ioctl with the same received UUID
field for a lot of subvolumes, we will hit the overflow, trigger the
transaction abort and turn the filesystem into RO mode. A malicious user
could exploit this, and this ioctl does not even requires that a user
has admin privileges (CAP_SYS_ADMIN), only that he/she owns the subvolume.
Fix this by doing an early check for item overflow before starting a
transaction. This is also race safe because we are holding the subvol_sem
semaphore in exclusive (write) mode.
A test case for fstests will follow soon.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-05-08