Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
bpf: Mark bpf_refcount field as unique
BPF_REFCOUNT is not marked as a unique field, while it should be. Fix
this oversight.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-09-25
In the Linux kernel, the following vulnerability has been resolved:
nvmet-rdma: fix queue leak when connect backlog is exceeded
When pending disconnecting queues exceed the backlog limit, the
connect path only drops the device reference and leaks the newly
allocated queue and its IB resources.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-09-25
In the Linux kernel, the following vulnerability has been resolved:
ntfs: bound $AttrDef table walk to the loaded table size
ntfs_attr_find_in_attrdef() walks the in-memory $AttrDef table, but the
loop condition bounds only the start of each entry, not the whole entry:
for (ad = vol->attrdef; (u8 *)ad - (u8 *)vol->attrdef <
vol->attrdef_size && ad->type; ++ad)
struct attr_def is 160 bytes; the guard reads ad->type at offset 128 and
the loop body reads further fields. vol->attrdef is kvzalloc(i_size),
where i_size is the on-disk $AttrDef data size, checked in
load_and_init_attrdef() only as 0 < i_size <= 0x7fffffff. A volume whose
$AttrDef data size is smaller than one entry (e.g. 120 bytes) makes the
read of ad->type run past the allocation. Creating a file reaches this
through ntfs_attr_size_bounds_check() and reads out of bounds:
BUG: KASAN: slab-out-of-bounds in ntfs_attr_find_in_attrdef+0x66/0xa0
Read of size 4 at addr ffff888005833280 by task init/1
ntfs_attr_find_in_attrdef
ntfs_attr_size_bounds_check
ntfs_attr_can_be_non_resident
ntfs_attr_add
Require the whole entry to lie within attrdef_size in the loop guard, and
reject at mount a $AttrDef too small to hold one attr_def entry.
CVSS Score
7.1
EPSS Score
0.001
Published
2026-09-25
In the Linux kernel, the following vulnerability has been resolved:
ntfs: treat any nonzero dio zero-range return as an error
ntfs_dio_zero_range() returns either 0 or a negative errno from
blkdev_issue_zeroout(); it never returns a positive value. The
zeroing failure check in ntfs_attr_fallocate() therefore never fired,
so a failed zeroing operation was silently ignored: the loop kept
going, the newly allocated clusters were folded into initialized_size
and the write could succeed leaving stale on-disk data.
Treat any nonzero return as an error and abort the allocation.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-09-25
In the Linux kernel, the following vulnerability has been resolved:
ntfs: do not mark the volume clean in sync_fs when errors were recorded
ntfs_put_super() and the remount-read-only path both clear the dirty bit
only when NVolErrors(vol) is false. ntfs_sync_fs() clears it
unconditionally, so any sync() on a volume that recorded an error marks
that volume clean. A volume without this set is then seen as not needing
recovery and it does not run one, so whatever went wrong is never repaired.
This change skips resetting the dirty bit when there are volume errors.
Reproduced on a volume whose $MFTMirr does not match $MFT, which sets the
error flag while leaving the mount read-write: after a write and a sync,
the on-disk volume flags read 0x0000 with this driver and 0x0001 with the
guard in place.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-09-25
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
0.002
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
0.002
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
0.002
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
0.002
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
0.002
Published
2026-09-25