Linux: >> Linux Kernel >> 6.1.175 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
NFSD: Fix SECINFO_NO_NAME decode error cleanup
nfsd4_decode_secinfo_no_name() currently initializes sin_exp after
decoding sin_style. If the XDR stream is truncated, the decoder returns
nfserr_bad_xdr before sin_exp is initialized.
Since commit 3fdc54646234 ("NFSD: Reduce amount of struct
nfsd4_compoundargs that needs clearing"), the inline iops array is not
cleared between RPC calls. A failed SECINFO_NO_NAME decode can therefore
leave sin_exp holding stale union contents from a previous operation.
The error response path still invokes nfsd4_secinfo_no_name_release(),
which calls exp_put() on a non-NULL sin_exp.
Initialize sin_exp before the first failable decode step, matching
nfsd4_decode_secinfo().
CVSS Score
9.8
EPSS Score
0.005
Published
2026-07-19
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: reject non-VALID session in compound request branch
smb2_check_user_session() takes a shortcut for any operation that is not
the first in a COMPOUND request: it reuses work->sess (the session bound by
the first operation) and validates only the SessionId, then returns
"valid". It never re-checks work->sess->state == SMB2_SESSION_VALID, and a
SessionId of 0xFFFFFFFFFFFFFFFF (ULLONG_MAX, the MS-SMB2 related-operation
value) skips even the id comparison. The standalone path
(ksmbd_session_lookup_all() plus the SESSION_SETUP state machine) does
enforce the VALID state; the compound branch bypasses all of it.
A SESSION_SETUP carrying only an NTLM Type-1 (NtLmNegotiate) blob publishes
a fresh SMB2_SESSION_IN_PROGRESS session whose sess->user is still NULL
(->user is assigned later, by ntlm_authenticate()). Used as operation 1 of
a COMPOUND with operation 2 = TREE_CONNECT (related, SessionId=ULLONG_MAX,
\\host\IPC$), the tree-connect then runs on that IN_PROGRESS session and
reaches ksmbd_ipc_tree_connect_request(), which dereferences
user_name(sess->user) with sess->user == NULL (transport_ipc.c:687/701/704)
-> remote NULL-pointer dereference and a kernel Oops that wedges the ksmbd
worker for all clients.
Reject any non-first compound operation that lands on a session which is
not SMB2_SESSION_VALID, mirroring the validity the standalone lookup path
enforces. SESSION_SETUP itself legitimately runs on an IN_PROGRESS session,
but it is never carried as a non-first compound operation, so multi-leg
authentication is unaffected by this check.
CVSS Score
7.5
EPSS Score
0.007
Published
2026-07-19
In the Linux kernel, the following vulnerability has been resolved:
serial: 8250_dw: unregister 8250 port if clk_notifier_register() fails
dw8250_probe() registers the 8250 port via serial8250_register_8250_port()
and then, if the device has a clock, registers a clock notifier. If
clk_notifier_register() fails, probe returns the error but leaves the
8250 port registered. The matching serial8250_unregister_port() lives
in dw8250_remove(), which is not called when probe fails, so the port
slot stays occupied until the device is rebound or the system is
rebooted. The devm-allocated driver data is freed while the port still
references it (via the saved private_data and serial_in/serial_out
callbacks), so any access to that port slot before a rebind is a
use-after-free hazard.
Unregister the port on the clk_notifier_register() error path.
CVSS Score
9.8
EPSS Score
0.005
Published
2026-07-19
In the Linux kernel, the following vulnerability has been resolved:
vc_screen: fix null-ptr-deref in vcs_notifier() during concurrent vcs_write
A KASAN null-ptr-deref was observed in vcs_notifier():
BUG: KASAN: null-ptr-deref in vcs_notifier+0x98/0x130
Read of size 2 at addr qmp_cmd_name: qmp_capabilities, arguments: {}
The issue is a race condition in vcs_write(). When the console_lock is
temporarily dropped (to copy data from userspace), the vc_data pointer
obtained from vcs_vc() may become stale. After re-acquiring the lock,
vcs_vc() is called again to re-validate the pointer. If the vc has been
deallocated in the meantime, vcs_vc() returns NULL, and the while loop
breaks (with written > 0). However, after the loop, vcs_scr_updated(vc)
is still called with the now-NULL vc pointer, leading to a null pointer
dereference in the notifier chain (vcs_notifier dereferences param->vc).
Fix this by adding a NULL check for vc before calling vcs_scr_updated().
CVSS Score
5.5
EPSS Score
0.002
Published
2026-07-19
In the Linux kernel, the following vulnerability has been resolved:
fuse: re-lock request before replacing page cache folio
fuse_try_move_folio() unlocks the request on entry but does not
re-lock it on the success path. This means fuse_chan_abort() can end the
request and free the fuse_io_args (eg fuse_readpages_end()) while the
subsequent copy chain logic after fuse_try_move_folio() accesses the
fuse_io_args, leading to use-after-free issues.
Fix this by calling lock_request() before replace_page_cache_folio().
This ensures the request is locked on the success path which will
prevent the fuse_io_args from being freed while the later copying logic
runs, and also ensures that the ap->folios[i]->mapping is never null
since ap->folios[i] will always point to the newfolio after
replace_page_cache_folio().
CVSS Score
7.8
EPSS Score
0.001
Published
2026-07-19
In the Linux kernel, the following vulnerability has been resolved:
virtiofs: fix UAF on submount umount
iput() called from fuse_release_end() can Oops if the super block has
already been destroyed. Normally this is prevented by waiting for
num_waiting to go down to zero before commencing with super block shutdown.
This only works, however, for the last submount instance, as the wait
counter is per connection, not per superblock.
Revert to using synchronous release requests for the auto_submounts case,
which is virtiofs only at this time.
CVSS Score
7.8
EPSS Score
0.001
Published
2026-07-19
In the Linux kernel, the following vulnerability has been resolved:
media: vidtv: fix NULL pointer dereference in vidtv_mux_push_si
syzbot reported a general protection fault in
vidtv_psi_ts_psi_write_into [1].
vidtv_mux_get_pid_ctx() can return NULL, but vidtv_mux_push_si() does
not check for this before dereferencing the returned pointer to access
the continuity counter. This leads to a general protection fault when
accessing a near-NULL address.
The root cause is that vidtv_mux_pid_ctx_init() does not check the
return value of vidtv_mux_create_pid_ctx_once() for PMT section PIDs.
If the allocation fails, the PID context is never created, but init
returns success. The subsequent vidtv_mux_push_si() call then gets
NULL from vidtv_mux_get_pid_ctx() and crashes.
Fix both the root cause (add error check in vidtv_mux_pid_ctx_init
for PMT PIDs) and add defensive NULL checks in vidtv_mux_push_si for
all vidtv_mux_get_pid_ctx() calls.
[1]
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
Workqueue: events vidtv_mux_tick
RIP: 0010:vidtv_psi_ts_psi_write_into+0x54a/0xbc0 drivers/media/test-drivers/vidtv/vidtv_psi.c:197
Call Trace:
<TASK>
vidtv_psi_table_header_write_into drivers/media/test-drivers/vidtv/vidtv_psi.c:799 [inline]
vidtv_psi_pmt_write_into+0x3b2/0xa70 drivers/media/test-drivers/vidtv/vidtv_psi.c:1231
vidtv_mux_push_si+0x932/0xe80 drivers/media/test-drivers/vidtv/vidtv_mux.c:196
vidtv_mux_tick+0xe9b/0x1480 drivers/media/test-drivers/vidtv/vidtv_mux.c:408
CVSS Score
5.5
EPSS Score
0.002
Published
2026-07-19
In the Linux kernel, the following vulnerability has been resolved:
drm/amdkfd: Add upper bound check for num_of_nodes
drm/amdkfd: Add upper bound check for num_of_nodes
in kfd_ioctl_get_process_apertures_new.
(cherry picked from commit 98ff46a5ea090c14d2cdb4f5b993b05d74f3949f)
CVSS Score
5.5
EPSS Score
0.002
Published
2026-07-19
In the Linux kernel, the following vulnerability has been resolved:
drm/msm: always recover the gpu
Previously, in case there was no more work to do, recover worker
wouldn't trigger recovery and would instead rely on the gpu going to
sleep and then resuming when more work is submitted.
Recover_worker will first increment the fence of the hung ring so, if
there's only one job submitted to a ring and that causes an hang, it
will early out.
There's no guarantee that the gpu will suspend and resume before more
work is submitted and if the gpu is in a hung state it will stay in that
state and probably trigger a timeout again.
Just stop checking and always recover the gpu.
Patchwork: https://patchwork.freedesktop.org/patch/704066/
CVSS Score
5.5
EPSS Score
0.002
Published
2026-07-19
In the Linux kernel, the following vulnerability has been resolved:
f2fs: fix fsck inconsistency caused by incorrect nat_entry flag usage
f2fs_need_dentry_mark() reads nat_entry flags without mutual exclusion
with the checkpoint path, which can result in an incorrect inode block
marking state. The scenario is as follows:
create & write & fsync 'file A' write checkpoint
- f2fs_do_sync_file // inline inode
- f2fs_write_inode // inode folio is dirty
- f2fs_write_checkpoint
- f2fs_flush_merged_writes
- f2fs_sync_node_pages
- f2fs_fsync_node_pages // no dirty node
- f2fs_need_inode_block_update // return true
- f2fs_fsync_node_pages // inode dirtied
- f2fs_need_dentry_mark //return true
- f2fs_flush_nat_entries
- f2fs_write_checkpoint end
- __write_node_folio // inode with DENT_BIT_SHIFT set
SPO, "fsck --dry-run" find inode has already checkpointed but still
with DENT_BIT_SHIFT set
The state observed by f2fs_need_dentry_mark() can differ from the state
observed in __write_node_folio() after acquiring sbi->node_write. The
root cause is that the semantics of IS_CHECKPOINTED and
HAS_FSYNCED_INODE are only guaranteed after the checkpoint write has
fully completed.
This patch moves set_dentry_mark() into __write_node_folio() and
protects it with the sbi->node_write lock.
CVSS Score
7.1
EPSS Score
0.001
Published
2026-07-19