Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
ntfs: only count successfully cleared runs when freeing clusters
ntfs_cluster_free_from_rl_nolock() adds a run's length to nr_freed
whenever the error bookkeeping condition is false, which includes
cases where ntfs_bitmap_clear_run() actually failed - e.g. a second
run failing with the same errno as an earlier one, or any failure
after a non-ENOMEM error was already recorded. Since a failed
ntfs_bitmap_clear_run() rolls back its partial modifications, no
bits were cleared for that run, yet its length still inflates
vol->free_clusters, corrupting statfs output and the allocator's
free space gate.
Only count runs whose bitmap clear succeeded.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-09-25
In the Linux kernel, the following vulnerability has been resolved:
net: stmmac: fix dma mapping leak in stmmac_tso_xmit()
In stmmac_tso_xmit(), if the DMA mapping of an skb fragment fails, the
frame is dropped but the DMA mappings already created for the linear
part and for the fragments mapped before the failure are never
unmapped, leaking DMA mappings.
Fix the leak by walking back over the descriptors used by the frame and
releasing each of them with stmmac_free_tx_buffer(). Moreover, release
the descriptors with stmmac_release_tx_desc() unmapping the DMA buffers.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-09-25
In the Linux kernel, the following vulnerability has been resolved:
bpf: don't downgrade half-dead scalar zero spills to STACK_ZERO
states.c:__clean_func_state() can downgrade scalar zero spill to
STACK_ZERO in the following case:
*(u64 *)(r10 - 8) = 0;
... checkpoint ...
r1 = *(u32 *)(r10 - 4);
... no reads from r10-8 ...
Here 4 bytes at r10-8 are dead and verifier changes scalar spill to a
combination: 0000pppp (p stands for poison). Such a change breaks
precision propagation chains. All places that produce STACK_ZERO
should call bpf_mark_chain_precision() for the zero source.
This patch fixes the bug in a simplest way possible:
avoids converting stack spills of zero to STACK_ZERO.
Two smarter approaches are possible:
- do bpf_mark_chain_precision() from __clean_func_state()
- check slot liveness information in check_stack_write_fixed_off()
I investigated both and the changes required are a bit tricky,
hence go with a simple fix for the time being.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-09-25
In the Linux kernel, the following vulnerability has been resolved:
ntfs: leave HasEA flag untouched on setxattr failure
In ntfs_set_ea(), the exit path unconditionally updates the HasEA
flag based on ea_info_qsize. When an error occurs before
ea_info_qsize is updated, NInoClearHasEA() hides existing on-disk
EAs until the inode is evicted.
Only update the flag on success.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-09-25
In the Linux kernel, the following vulnerability has been resolved:
bpf: check_cond_jmp_op(): properly infer if register is null
Nicholas Carlini reported a bug when verifier can incorrectly infer
that a pointer is non-null. The bug occurs when two pointers are
compared and one of them has a type w/o PTR_MAYBE_NULL flag,
but which allows a value to be NULL at runtime.
Here is an example:
// `a` is PTR_TO_MEM | MEM_RDONLY | PTR_UNTRUSTED
// `a` is 0 at runtime.
// `b` is PTR_TO_MAP_VALUE | PTR_MAYBE_NULL
void *a = bpf_rdonly_cast(0, 0);
int *b = bpf_map_lookup_elem(...);
if (a == b)
*b = 42; // verifier does not catch null pointer dereference
This happens because of a special case in check_cond_jmp_op(),
which attempts to strip PTR_MAYBE_NULL flags from pointer types,
when processing comparisons like `rA == rB`, if either rA or rB can't
be null.
The non-null property is derived based on the absence of
PTR_MAYBE_NULL flag on rA's or rB's type. But that is not sufficient
for types like PTR_TO_MEM, as in the example.
This patch replaces type_may_be_null() call with reg_not_null(),
which contains an allowlist of types for which absence of
PTR_MAYBE_NULL actually means that the value can't be NULL at runtime.
At the moment, the list in the reg_not_null() omits two types for
which PTR_MAYBE_NULL is applicable: PTR_TO_XDP_SOCK and PTR_TO_BUF.
In order to remain backward compatible, and assuming that only
comparison between pointers of the same type makes sense,
this commit extends reg_not_null(). W/o such an extension e.g.
verifier_jeq_infer_not_null/null_ptr_to_map_value fails.
reg_not_null() can be extended further, but I deem that out of scope
for the fix at hand. Explicit base_type(...) != PTR_TO_BTF_ID
checks in the check_cond_jmp_op() can be removed with migration to
reg_not_null(), but that is a behavioural change, as the special case
would start matching for PTR_TO_BTF_ID that is also is_trusted_reg().
I omit the behavioural change from this commit.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-09-25
In the Linux kernel, the following vulnerability has been resolved:
ntfs: reject invalid sectors_per_cluster in the boot sector
is_boot_sector_ntfs() checks the boot sector's sectors_per_cluster field
with a range test that rejects 0x81..0xf3 but accepts 0 and other
non-power-of-two counts. A zero value reaches parse_ntfs_boot_sector():
sectors_per_cluster_bits = ffs(sectors_per_cluster) - 1;
...
vol->cluster_size = vol->sector_size << sectors_per_cluster_bits;
ffs(0) is 0, so sectors_per_cluster_bits becomes (unsigned)-1 and the
shift is undefined:
UBSAN: shift-out-of-bounds in fs/ntfs/super.c:673:39
shift exponent 4294967295 is too large for 32-bit type 'int'
This change rejects any non-power-of-two value, since it feeds the
aforementioned shift via ffs() - 1, which only yields the correct shift for a
power of two.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-09-25
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: safely drain sessions during logoff
SMB3 multichannel allows requests for one session to run on multiple
connections. Wait for all channels bound to a session before freeing
shared session objects.
A deferred byte-range lock remains counted as a running request and only
wakes when its file closes. Wake blocked locks during the drain without
unpublishing or modifying their file objects. Synchronous CANCEL requests
must invoke their cancellation callback to wake pending operations, while
CHANGE_NOTIFY completion remains specific to the asynchronous path.
Serialize session teardown with channel registration and previous-session
cleanup, and use atomic work-state transitions so LOGOFF, CANCEL, and
connection teardown invoke cancellation callbacks only once.
CVSS Score
8.8
EPSS Score
0.003
Published
2026-09-25
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: hci_core: Fix race condition during device registration
In hci_register_dev(), the power_on work item is queued to
hdev->req_workqueue before initializing hdev->adv_monitors_idr and
registering the MSFT extension via msft_register(). For devices marked with
quirks such as HCI_QUIRK_RAW_DEVICE, the HCI_UNCONFIGURED flag is set on
the device. When the power_on work item runs concurrently on another CPU,
hci_power_on() detects that the device is unconfigured and immediately
invokes hci_dev_do_close(), which calls msft_do_close().
Concurrently, msft_register() allocates the msft structure and exposes it
to hdev->msft_data prior to calling mutex_init(&msft->filter_lock). If
msft_do_close() executes while hdev->msft_data is already assigned but the
mutex has not yet been initialized, mutex_lock(&msft->filter_lock) operates
on an uninitialized mutex, triggering a DEBUG_LOCKS warning:
DEBUG_LOCKS_WARN_ON(lock->magic != lock)
WARNING: kernel/locking/mutex.c:625 at __mutex_lock_common
kernel/locking/mutex.c:625 [inline]
WARNING: kernel/locking/mutex.c:625 at __mutex_lock+0x12d8/0x1550
kernel/locking/mutex.c:821
...
Call Trace:
<TASK>
msft_do_close+0x308/0x7b0 net/bluetooth/msft.c:693
hci_dev_close_sync+0x86b/0x10a0 net/bluetooth/hci_sync.c:5522
hci_dev_do_close net/bluetooth/hci_core.c:499 [inline]
hci_power_on+0x32c/0x750 net/bluetooth/hci_core.c:937
process_one_work kernel/workqueue.c:3322 [inline]
process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405
worker_thread+0x92d/0xe10 kernel/workqueue.c:3486
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
Fix this by moving the queue_work() call in hci_register_dev() to after
idr_init(&hdev->adv_monitors_idr) and msft_register(hdev) so that device
structures and extensions are fully initialized before asynchronous tasks
can access them. Additionally, assign hdev->msft_data in msft_register()
only after mutex_init(&msft->filter_lock) has completed.
CVSS Score
4.7
EPSS Score
0.001
Published
2026-09-25
In the Linux kernel, the following vulnerability has been resolved:
ipvs: fix reversed sequence option serialization
hton_seq() expects the host-order source first and the unaligned
network-order destination second. The version 1 sync sender passes these
arguments in reverse for both sequence blocks. This leaves 24 bytes of the
kmalloc-backed message unwritten. It may disclose stale heap data and
replace the live connection sequence state with values read from the
buffer.
Pass the connection sequence state as the source and the message payload as
the destination for both blocks.
CVSS Score
4.4
EPSS Score
0.002
Published
2026-09-25
In the Linux kernel, the following vulnerability has been resolved:
btrfs: do not force reloc root creation during qgroup_account_snapshot()
[BUG]
When running btrfs/252 with quota enabled through MKFS_OPTIONS="-O quota",
it has a high chance to trigger the following kernel warning and flips
the fs RO:
BTRFS info (device dm-2): relocating block group 30408704 flags metadata|dup
------------[ cut here ]------------
WARNING: fs/btrfs/extent-tree.c:879 at lookup_inline_extent_backref+0x74b/0x960 [btrfs], CPU#4: btrfs/2173
CPU: 4 UID: 0 PID: 2173 Comm: btrfs Not tainted 7.2.0-rc6-custom+ #457 PREEMPT(full) 3adc6528fb66f7a55fe1095385818e742f200aab
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS unknown 02/02/2022
RIP: 0010:lookup_inline_extent_backref+0x74b/0x960 [btrfs]
Call Trace:
<TASK>
insert_inline_extent_backref+0x7c/0x160 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72]
__btrfs_inc_extent_ref+0xa9/0x270 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72]
__btrfs_run_delayed_refs+0x4af/0x11c0 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72]
btrfs_run_delayed_refs+0x9d/0xf0 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72]
create_pending_snapshot+0x39d/0xf00 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72]
create_pending_snapshots+0x9b/0xc0 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72]
btrfs_commit_transaction+0x280/0xeb0 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72]
prepare_to_relocate+0x147/0x200 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72]
relocate_block_group+0x6b/0x5e0 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72]
btrfs_relocate_block_group+0x92c/0x2380 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72]
btrfs_relocate_chunk+0x3f/0x1a0 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72]
btrfs_balance+0xa2c/0x19c0 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72]
btrfs_ioctl+0x2839/0x2d30 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72]
__x64_sys_ioctl+0x416/0x9a0
do_syscall_64+0xe1/0x790
entry_SYSCALL_64_after_hwframe+0x4b/0x53
</TASK>
---[ end trace 0000000000000000 ]---
BTRFS info (device dm-2): leaf 4593991680 gen 233 total ptrs 175 free space 5953 owner 2
BTRFS info (device dm-2): refs 3 lock_owner 2173 current 2173
item 0 key (166772736 METADATA_ITEM 1) itemoff 16250 itemsize 33
extent refs 1 gen 222 flags 2
ref#0: tree block backref root 266
[ Skip the tree dump ]
item 174 key (263225344 METADATA_ITEM 0) itemoff 10328 itemsize 33
extent refs 1 gen 162 flags 258
ref#0: tree block backref root 267
BTRFS error (device dm-2): extent item not found for insert, bytenr 179847168 num_bytes 16384 parent 4594335744 root_objectid 273 owner 0 offset 0
BTRFS error (device dm-2): failed to run delayed ref for logical 179847168 num_bytes 16384 type 182 action 1 ref_mod 1: -117
[CAUSE]
The above error is showing that there is a tree reference to a metadata
extent that is no longer there.
With "ref_verify" mount option (requires CONFIG_BTRFS_DEBUG), there is
some extra debug output:
BTRFS error (device dm-2): dumping block entry [180961280 16384], num_refs 0, metadata 1, from disk 0
BTRFS error (device dm-2): root entry 256, num_refs 18446744073709551615
BTRFS error (device dm-2): root entry 273, num_refs 18446744073709551615
BTRFS error (device dm-2): Ref action 3, root 273, ref_root 273, parent 0, owner 0, offset 0, num_refs 1
btrfs_force_cow_block+0x129/0x7d0 [btrfs]
btrfs_cow_block+0x10a/0x250 [btrfs]
btrfs_search_slot+0x5eb/0xf40 [btrfs]
btrfs_insert_empty_items+0x3a/0x70 [btrfs]
insert_with_overflow+0x53/0x130 [btrfs]
btrfs_insert_dir_item+0x125/0x290 [btrfs]
btrfs_add_link+0xaa/0x410 [btrfs]
btrfs_rename+0x5ea/0xcd0 [btrfs]
btrfs_rename2+0x28/0x60 [btrfs]
vfs_rename+0x5b2/0xe10
filename_renameat2+0x244/0x430
__x64_sys_rename+0x48/0x70
do_syscall_64+0xe1/0x790
entry_SYSCALL_64_after_hwframe+0x4b/0x53
---truncated---
CVSS Score
5.5
EPSS Score
0.001
Published
2026-09-25