| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
iommu/iommufd: Fix NULL pointer deref in iommufd_ioas_change_process when racing with iopt_map_file_pages
iommufd_ioas_change_process() iterates every IOAS area while only
holding every IOAS iova_rwsem, so it assumes every area has a non-NULL
pages pointer. That assumption can be false when it runs concurrently
with iopt_map_file_pages().
iopt_map_pages() executes in two phases. It first creates the area and
inserts it into the interval tree under iova_rwsem, with area->pages
still NULL. It then drops iova_rwsem and later fills area->pages
under domains_rwsem. This leaves a window between area creation and
area->pages fill where a concurrent iommufd_ioas_change_process()
can observe the area and dereference a NULL area->pages pointer,
leading to a NULL pointer dereference:
BUG: kernel NULL pointer dereference, address: 00000000000000c0
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 4b655067 P4D 4b655067 PUD 0
Oops: Oops: 0000 [#1] SMP NOPTI
CPU: 0 UID: 0 PID: 11841 Comm: syz.1.628 Not tainted 7.1.0 #3 PREEMPT(full)
Hardware name: QEMU Ubuntu 24.04 PC v2 (i440FX + PIIX, arch_caps fix, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:iommufd_ioas_change_process+0x419/0xd50 drivers/iommu/iommufd/ioas.c:538
Code: 48 89 c3 48 85 c0 0f 84 cc 00 00 00 e8 10 f5 cb fd 48 8d 7b 68 e8 a7 b5 eb fd 48 8b 6b 68 48 8d bd c0 00 00 00 e8 17 b2 eb fd <8b> ad c0 00 00 00 bf 01 00 00 00 89 ee e8 85 ef cb fd 83 fd 01 74
RSP: 0018:ffffc90015c17d28 EFLAGS: 00010246
RAX: ffff8880186d5328 RBX: ffff88801d25e240 RCX: 0000000080000000
RDX: 00000000000002d7 RSI: ffffffff83ba9e10 RDI: 00000000000000c0
RBP: 0000000000000000 R08: ffffffff8e781eb8 R09: 0000000000000000
R10: 00000000000000c0 R11: ffffffff83ba9e29 R12: ffff88802e216008
R13: ffff88802e216000 R14: 0000000000000001 R15: 0000000000000000
FS: 00007f4aea3f66c0(0000) GS:ffff8880b1fa1000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000000000c0 CR3: 000000004b75c000 CR4: 0000000000350ef0
Call Trace:
<TASK>
iommufd_fops_ioctl+0x287/0x400 drivers/iommu/iommufd/main.c:533
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl fs/ioctl.c:583 [inline]
__x64_sys_ioctl+0x120/0x170 fs/ioctl.c:583
x64_sys_call+0x1092/0x1fb0 arch/x86/include/generated/asm/syscalls_64.h:17
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x10a/0x680 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4aec1a82bd
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f4aea3f6018 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f4aec436090 RCX: 00007f4aec1a82bd
RDX: 0000200000000180 RSI: 0000000000003b92 RDI: 0000000000000003
RBP: 00007f4aec250295 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4aec436128 R14: 00007f4aec436090 R15: 00007ffd04ef23e0
</TASK>
Modules linked in:
CR2: 00000000000000c0
---[ end trace 0000000000000000 ]---
RIP: 0010:iommufd_ioas_change_process+0x419/0xd50 drivers/iommu/iommufd/ioas.c:538
Code: 48 89 c3 48 85 c0 0f 84 cc 00 00 00 e8 10 f5 cb fd 48 8d 7b 68 e8 a7 b5 eb fd 48 8b 6b 68 48 8d bd c0 00 00 00 e8 17 b2 eb fd <8b> ad c0 00 00 00 bf 01 00 00 00 89 ee e8 85 ef cb fd 83 fd 01 74
RSP: 0018:ffffc90015c17d28 EFLAGS: 00010246
RAX: ffff8880186d5328 RBX: ffff88801d25e240 RCX: 0000000080000000
RDX: 00000000000002d7 RSI: ffffffff83ba9e10 RDI: 00000000000000c0
RBP: 0000000000000000 R08: ffffffff8e781eb8 R09: 0000000000000000
R10: 00000000000000c0 R11: ffffffff83ba9e29 R12: ffff88802e216008
R13: ffff88802e216000 R14: 0000000000000001 R15: 0000000000000000
FS: 00007f4aea3f66c0(000
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
ALSA: FCP: Use a private URB for the notification endpoint
fcp_init_notify() used mixer->urb, which snd_usb_mixer_status_create()
allocates for the optional UAC2 status interrupt endpoint and mixer.c
kills, resubmits and frees. On a device with that endpoint,
fcp_init_notify()'s "already set up" early return fires on the status
URB and returns success without doing anything. No FCP notification
URB is submitted, and cmd_done is left zeroed because it is
initialised past that early return and nowhere else. fcp_init() then
issues init1_opcode and wait_for_completion_timeout() would crash
adding to the zeroed wait.head. fcp_cleanup_urb() would also kill and
free mixer.c's status URB.
Use a separate URB in fcp_data, and initialise cmd_done in
fcp_init_private() where fcp_data is allocated. fcp_init_notify() is
reached again after suspend via fcp_reinit(), and the URB kill path in
fcp_notify() completes cmd_done, leaving a stale count that would
satisfy the next command's wait before the device ACKs. Use
reinit_completion() to clear it. |
| In the Linux kernel, the following vulnerability has been resolved:
ALSA: scarlett2: Use a private URB for the notification endpoint
scarlett2_init_notify() used mixer->urb, which
snd_usb_mixer_status_create() allocates for the UAC2 status interrupt
endpoint and mixer.c manages. On a device with that endpoint, the
"already in use" check fires on the status URB and returns 0 for
success without doing anything. No notification URB is submitted, and
cmd_done is left zeroed because it is initialised past that check and
nowhere else. scarlett2_usb_init() then issues SCARLETT2_USB_INIT_1
and wait_for_completion_timeout() would crash adding to the zeroed
wait.head.
Use a separate URB in scarlett2_data, as done for FCP, and initialise
cmd_done in scarlett2_init_private(). mixer.c was also freeing the URB
in snd_usb_mixer_free() and resubmitting it in
snd_usb_mixer_activate(), so scarlett2 must now do both: add
scarlett2_cleanup_urb(), called from private_free and private_suspend,
and a private_resume callback to re-establish the URB after resume.
scarlett2_init_notify() is reached from there, and the URB kill path
in scarlett2_notify() completes cmd_done, leaving a stale count that
would satisfy the next command's wait before the device ACKs. Use
reinit_completion() to clear it.
Also free the URB if the transfer buffer allocation fails, and both if
usb_submit_urb() fails. Move scarlett2_init_notify() up next to
scarlett2_cleanup_urb() so scarlett2_init_private() can reference it
without a forward declaration. |
| In the Linux kernel, the following vulnerability has been resolved:
rndis_host: add overflow check in rndis_rx_fixup()
Add an overflow check to ensure that data_offset + data_len + 8 does not
wrap, which would enable an OOB read of the USB data buffer. |
| In the Linux kernel, the following vulnerability has been resolved:
nvmet: fix NULL pointer dereference in nvmet_execute_identify_nslist()
When a host issues an Identify command with CNS 07h (Active Namespace ID
List for a specific I/O Command Set), nvmet_execute_identify_nslist() is
called with match_css set. The command-set filter dereferences req->ns,
but this handler never calls nvmet_req_find_ns(), so req->ns is always
NULL (nvmet_req_init() resets it to NULL). As soon as an enabled
namespace with an NSID greater than the requested value exists,
req->ns->csi dereferences a NULL pointer and oopses.
Besides the crash, the comparison is logically wrong: to filter the list
by command set it must test the command set of the namespace being
iterated, not a single fixed value. Use the loop variable ns->csi. |
| In the Linux kernel, the following vulnerability has been resolved:
ALSA: dummy: Check card index validity at probe
snd_dummy_probe() blindly trusts that the given devptr->id value is
within the proper card index range. It's OK for the devices the
driver itself creates at the module probe time, but if the device is
bound manually via sysfs interface, this could be -1 as "none", and
this leads to OOB access for index[] and other parameters.
Add a sanity check for the card index and warn/correct it if it's a
value out of the range. |
| In the Linux kernel, the following vulnerability has been resolved:
io_uring/cmd: fix iovec leak when the async cmd is not recycled
An io_async_cmd carries an iovec array in ->vec.iovec, allocated when the
vec has to grow and kept across recycling through ctx->cmd_cache. On two
paths nothing frees it and io_clean_op()'s kfree(req->async_data) drops
the io_async_cmd without it.
io_req_uring_cleanup() clears the async data flags only when
io_alloc_cache_put() succeeds, and the cache holds IO_ALLOC_CACHE_MAX ==
128 entries, so once it is full the put fails and the vec is left behind.
An NVMe passthrough workload gets there without doing anything unusual:
nvme_uring_cmd_io() returns -EIOCBQUEUED, so the io_async_cmd stays
attached for the lifetime of the command and the live object count tracks
the queue depth. Above 128 the puts start failing.
->cleanup is the last chance to free an inherited vec, since
io_req_uring_cleanup() returns early for an io-wq issued command and is
not called at all for one completed without ever being issued. But
io_clean_op() calls ->cleanup only if REQ_F_NEED_CLEANUP is set, and for
uring_cmd that happens only where the vec has to grow, so a command
reusing a large enough cached vec never sets it. io_rw_alloc_async() and
io_msg_alloc_async() flag an inherited vec for exactly this reason;
io_uring_cmd_prep() does not.
Flag an inherited vec in io_uring_cmd_prep(), and free the vec when the
cache put fails, as io_req_rw_cleanup() does.
The leak is invisible under KASAN, where io_alloc_cache_vec_kasan() frees
the vec unconditionally. |
| In the Linux kernel, the following vulnerability has been resolved:
io_uring/rsrc: fix folio size overflow in io_vec_fill_bvec()
io_vec_fill_bvec() computes the folio size with a plain int 1:
unsigned long folio_size = 1 << imu->folio_shift;
imu->folio_shift is unsigned int and comes from folio_shift() of the
folio backing the registered buffer, so it can be 32 or more on a 64 bit
kernel. Shifting int 1 that far is undefined, and on x86 and arm64 the
count is taken modulo 32, so a shift of 34 yields 4 rather than 16G.
Every other folio_shift shift in this file already uses 1UL.
The result is that the segment estimate and the fill loop disagree.
io_estimate_bvec_size() sizes the bvec array with the real shift:
max_segs += (iov[i].iov_len >> shift) + 2;
so a 1M iovec on a 16G folio is charged 2 segments, while
io_vec_fill_bvec() then walks the same iovec in folio_size chunks of 4
bytes and writes res_bvec[bvec_idx] a quarter of a million times, past
the end of the array it was given. src_bvec is advanced once per
iteration as well, so imu->bvec is read past its end at the same time.
validate_fixed_range() only checks that the range is inside the
registered buffer and does not bound the segment count.
Reaching it needs a folio with a shift of at least 32, which means a
gigantic hugetlb page: 16G on arm64 with 64K pages, where
CONT_PMD_SHIFT is 34 and hugetlb_add_hstate(CONT_PMD_SHIFT - PAGE_SHIFT)
registers that size, and likewise on powerpc. x86_64 tops out at 1G, so
a shift of 30, which still fits in int and is unaffected.
Use 1UL, as the rest of the file does. |
| In the Linux kernel, the following vulnerability has been resolved:
ocfs2: fix missing metadata reservation for large xattrs
[BUG]
lsetxattr() panics the kernel when setting a large xattr value on a
fragmented filesystem where the file already has an external xattr
block.
[CAUSE]
ocfs2_calc_xattr_set_need() never reserves metadata blocks for a new
xattr value's extent tree when the file already has an external xattr
block. The not_found path leaves meta_add at zero, so meta_ac is NULL
when ocfs2_xattr_extend_allocation() runs.
A new value root has room for a single extent record. On a fragmented
filesystem, the allocator cannot satisfy the xattr value in one
contiguous run, so each non-contiguous run requires its own extent
record. When the value root's extent list is full and meta_ac is NULL,
ocfs2_add_clusters_in_btree() returns RESTART_META, and
ocfs2_xattr_extend_allocation() hits BUG_ON(why == RESTART_META).
[FIX]
The case where no xattr block exists yet already calls
ocfs2_extend_meta_needed(&def_xv.xv.xr_list) to reserve value tree
metadata. Add the same reservation to the case where an xattr block
already exists, making the two cases consistent.
Replace the BUG_ON with a -ENOSPC return so that if RESTART_META is
returned despite the reservation, the error propagates to userspace
instead of panicking the kernel. |
| In the Linux kernel, the following vulnerability has been resolved:
ext4: stop retrying saturated xattr cache entries
ext4_xattr_block_set() retries when a cache entry selected for reuse
has a saturated reference count after taking the buffer lock. The retry
returns to the mbcache lookup without making that entry ineligible, so
it can select the same unusable entry indefinitely. A task spinning
there can hold the parent directory's i_rwsem and leave concurrent
rmdir callers blocked.
Normally a reusable entry has a reference count below
EXT4_XATTR_REFCOUNT_MAX because the count and MBE_REUSABLE_B are
updated under the same buffer lock. A corrupted filesystem can violate
that invariant. The syzbot reproducer reports allocator and xattr
corruption before triggering this retry loop.
Check the untrusted on-disk count before incrementing it, avoiding
overflow, and clear MBE_REUSABLE_B when it is already saturated. The
next lookup then skips the entry that was just proven unusable. This
mirrors the normal transition at EXT4_XATTR_REFCOUNT_MAX; the release
path marks the entry reusable again on the exact 1024-to-1023
transition.
Using the same QEMU harness and guest parameters, current unpatched
Linux hung in 6 of 8 420-second trials with the do_rmdir signature;
representative NMI backtraces caught the owner spinning in
ext4_xattr_block_set(). The patched kernel completed 28 of 28 trials
without a hung-task report; the final twelve trials exercised the
reviewed overflow-safe form of the change. syzbot's patch testing also
completed without reproducing the hang. |
| In the Linux kernel, the following vulnerability has been resolved:
nilfs2: reject invalid block index in GC ioctl
Syzbot reported list corruption caused by a double list_add_tail() call on
bh->b_assoc_buffers within nilfs_lookup_dirty_data_buffers().
Analysis revealed that the root cause was the insertion of a page/folio
with a page index of ULONG_MAX into the page cache via the GC ioctl.
filemap_get_folios_tag(), called by nilfs_lookup_dirty_data_buffers(),
repeatedly detects a dirty folio with a page index of ULONG_MAX due to
index wrap-around, leading to duplicate processing of dirty buffers.
As a preparatory step, the GC ioctl loads the page/folio of the block to
be moved during GC and inserts it into the page cache based on information
in the nilfs_vdesc structure passed as an argument. Normally, this does
not cause issues because the user-space GC library configures the
nilfs_vdesc structure properly. However, since there is no range check on
the parameters determining the page index, a request with artificially
crafted parameters -- such as those generated by Syzbot -- can result in a
page/folio being inserted with a page index of ULONG_MAX, triggering the
above problem.
This resolves the issue by checking the ranges of 'vd_offset' and
'vd_vblocknr' in the nilfs_vdesc structure that determine the page index,
thereby preventing the invalid page/folio insertions. |
| In the Linux kernel, the following vulnerability has been resolved:
ext4: don't enable DAX on new encrypted files
Currently, when a new encrypted regular file is created, the call to
ext4_set_inode_flags(inode, init=true) in __ext4_new_inode() is made
before EXT4_INODE_ENCRYPT is set. As a result, it can set S_DAX if the
filesystem is mounted with "-o dax=always".
EXT4_INODE_ENCRYPT then actually gets set a bit later in
__ext4_new_inode(), when it calls fscrypt_set_context() which calls
ext4_set_context(). ext4_set_context() sets EXT4_INODE_ENCRYPT and
calls ext4_set_inode_flags(inode, init=false) to set S_ENCRYPTED too.
This was intended to clear S_DAX as well. However, this was broken by
commit 043546e46dc7 ("fs/ext4: Only change S_DAX on inode load"). This
causes data written to the file to bypass encryption, also causing
xfstests failures such as generic/548 (when "-o dax=always" is used).
Fix this by simplifying the flow by making __ext4_new_inode() set
EXT4_INODE_ENCRYPT earlier. This makes it take effect in
ext4_set_inode_flags(inode, init=true), making S_DAX never be set.
Similarly, make EXT4_STATE_MAY_INLINE_DATA never be set in the first
place on new encrypted inodes. Then it doesn't need to be cleared.
As a result of these simplifications, ext4_set_context() no longer needs
to change inode flags or state when 'handle != NULL'. Remove that too. |
| In the Linux kernel, the following vulnerability has been resolved:
xfs: validate attr entry pointer before field access
xfs_attr3_leaf_verify_entry() accesses lentry/rentry fields (namelen,
valuelen) before checking if the entry pointer itself is within bounds.
If nameidx is crafted to point near the end of the buffer, these field
accesses can read out-of-bounds before the bounds check at
name_end > buf_end is performed.
Add explicit bounds checks for entry pointers before accessing their
fields. Use offsetof() to check that the start of the flexible array
member (nameval/name) is within bounds, which ensures all preceding
fields are safe to access. |
| In the Linux kernel, the following vulnerability has been resolved:
xfs: restore nofs context unconditionally in xfs_trans_roll
When __xfs_trans_commit() fails in xfs_trans_roll(), the NOFS context
is cleared but only restored in the success path. This leaves the
error path without nofs protection, causing a circular lock dependency
between xfs_nondir_ilock_class and fs_reclaim:
CPU0 CPU1
---- ----
lock(&xfs_nondir_ilock_class);
lock(fs_reclaim);
lock(&xfs_nondir_ilock_class);
lock(fs_reclaim);
Fix this by moving xfs_trans_set_context() before the error check so
that nofs context is always restored on the new transaction. |
| In the Linux kernel, the following vulnerability has been resolved:
nfc: digital: clamp SENSF_RES length to the destination buffer
digital_in_recv_sensf_res() memcpy()s resp->len bytes from a remote
NFC-F device response into the NFC_SENSF_RES_MAXSIZE-byte target.sensf_res
field without an upper-bound check. A nearby malicious NFC-F device can
send an oversized SENSF_RES response to overflow the stack-local struct
nfc_target.
Clamp resp->len to NFC_SENSF_RES_MAXSIZE before the copy.
Found by 0sec automated security-research tooling (https://0sec.ai). |
| In the Linux kernel, the following vulnerability has been resolved:
nfc: fdp: bound the device-reported read length and fix an skb leak
fdp_nci_i2c_read() takes the next packet length from two device-supplied
bytes and never validates it. The value is a u16 used as the
i2c_master_recv() count into a 261-byte on-stack buffer: a malicious,
counterfeit or malfunctioning controller (or an i2c bus interposer) can
drive it far past the buffer for a stack out-of-bounds write that
clobbers the canary and return address, or below the minimum frame size
(directly, or by truncating the computed sum) so the header/LRC strip
and the next length read run past a short receive. Reject a length
outside [FDP_NCI_I2C_MIN_PAYLOAD, FDP_NCI_I2C_MAX_PAYLOAD], as a
corrupted packet already is, and force resynchronization.
The same loop allocates one data skb per iteration and assumes a length
packet followed by a data packet; a device that sends two data packets
in one call leaks the first skb when the second allocation overwrites
it. Free a previously allocated skb before allocating the next. |
| In the Linux kernel, the following vulnerability has been resolved:
nfc: microread: validate target discovery payload lengths
microread_target_discovered() parses target discovery payloads from
skb->data according to the HCI gate. The fixed field offsets and UID
copies were checked only against the destination nfc_target buffers, not
against the actual skb length.
Validate that each gate-specific payload contains the fixed fields and
UID bytes before reading or copying them. |
| In the Linux kernel, the following vulnerability has been resolved:
nfc: llcp: bound the connect_sn TLV walk to the skb
Commit 27256cdb290e ("nfc: llcp: bound SNL TLV parsing to the skb and
add length checks") fixed the unbounded TLV walk in nfc_llcp_recv_snl(),
and commit d8bd2dedbde5 ("nfc: llcp: fix OOB read and u8 offset wrap in
TLV parsers") subsequently bounded nfc_llcp_parse_gb_tlv() and
nfc_llcp_parse_connection_tlv(). One sibling parser sharing the same
pattern remains unbounded: nfc_llcp_connect_sn().
nfc_llcp_connect_sn() walks a TLV list, reading a two-byte header
(type, length) followed by length bytes of value, without checking that
the two header bytes or the declared length stay within the buffer. It
returns a pointer to a service name of up to 255 bytes that may point
past the end of the skb; it is subsequently consumed by memcmp() in
nfc_llcp_sock_from_sn(). In addition tlv_array_len was computed as
"skb->len - LLCP_HEADER_SIZE" in size_t, so a CONNECT/CC frame shorter
than the LLCP header underflows to a huge length and the walk runs far
past the buffer.
nfc_llcp_connect_sn() is reachable from nfc_llcp_recv_connect() and
nfc_llcp_recv_cc(), i.e. from received CONNECT and CC PDUs. A nearby
NFC device can reach this without authentication; LLCP link activation
happens automatically after NFC-DEP, and the nfc_llcp_rx_skb()
dispatcher applies no minimum-length guard.
Walk the TLV list by pointer, bounded by skb_tail_pointer(skb), and
validate each declared length before use, matching the approach already
used for nfc_llcp_recv_snl(). Starting the walk at
&skb->data[LLCP_HEADER_SIZE] against the tail pointer also removes the
size_t underflow for short frames.
Found by 0sec automated security-research tooling (https://0sec.ai). |
| In the Linux kernel, the following vulnerability has been resolved:
nfc: llcp: fix OOB read and u8 offset wrap in TLV parsers
nfc_llcp_parse_gb_tlv() and nfc_llcp_parse_connection_tlv() contain
three related bugs in their TLV parsing loops:
1. 'offset' is declared u8 but tlv_array_len is u16. When TLV data
advances offset past 255 it silently wraps to zero, causing
infinite loops or double-processing of buffer data.
2. Before reading tlv[0] (type) and tlv[1] (length) there is no
check that offset+2 <= tlv_array_len. A truncated TLV causes
an OOB read of one byte past the buffer end.
3. After reading the length field, the value bytes are accessed
without checking offset+2+length <= tlv_array_len. A crafted
length=0xFF on a short buffer causes up to 255 bytes of OOB
read past the buffer end.
Both functions are reachable without authentication via
nfc_llcp_set_remote_gb() which feeds remote LLCP general bytes
directly into nfc_llcp_parse_gb_tlv() with no additional
validation.
Fix all three issues by widening offset from u8 to u16 and adding
bounds checks for both the TLV header and value field before each
access. |
| In the Linux kernel, the following vulnerability has been resolved:
nfc: llcp: reject PDUs shorter than the LLCP header
Every LLCP PDU begins with a two-byte header (DSAP/SSAP + PTYPE), but the
receive path never checked that a frame is at least LLCP_HEADER_SIZE bytes
before parsing it.
nfc_llcp_rx_skb() reads the header via nfc_llcp_ptype()/nfc_llcp_dsap()/
nfc_llcp_ssap(), which dereference pdu->data[0] and pdu->data[1], and a
CONNECT or CC PDU then computes
tlv_array_len = skb->len - LLCP_HEADER_SIZE;
as a size_t and hands it to the TLV walk. When the frame is shorter than
the header the subtraction wraps to a huge value and the walk runs far
past the buffer, an out-of-bounds read.
A nearby NFC device can reach this without authentication; LLCP link
activation happens automatically after NFC-DEP.
Guard the common receive choke point __nfc_llcp_recv(), shared by both the
target (nfc_llcp_data_received()) and initiator (nfc_llcp_recv()) paths, so
a short skb is dropped before the rx_work worker parses it. Use
pskb_may_pull() rather than a skb->len test so the two header bytes are
guaranteed to sit in the skb linear area even for a non-linear skb,
matching how the sibling NCI and HCI receive paths validate their headers.
Reproduced with a KFENCE out-of-bounds read via /dev/virtual_nci on
linux-next.
Found by 0sec automated security-research tooling (https://0sec.ai). |
