Linux: >> Linux Kernel >> 4.16.10 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
net: sock: fix hardened usercopy panic in sock_recv_errqueue
skbuff_fclone_cache was created without defining a usercopy region,
[1] unlike skbuff_head_cache which properly whitelists the cb[] field.
[2] This causes a usercopy BUG() when CONFIG_HARDENED_USERCOPY is
enabled and the kernel attempts to copy sk_buff.cb data to userspace
via sock_recv_errqueue() -> put_cmsg().
The crash occurs when: 1. TCP allocates an skb using alloc_skb_fclone()
(from skbuff_fclone_cache) [1]
2. The skb is cloned via skb_clone() using the pre-allocated fclone
[3] 3. The cloned skb is queued to sk_error_queue for timestamp
reporting 4. Userspace reads the error queue via recvmsg(MSG_ERRQUEUE)
5. sock_recv_errqueue() calls put_cmsg() to copy serr->ee from skb->cb
[4] 6. __check_heap_object() fails because skbuff_fclone_cache has no
usercopy whitelist [5]
When cloned skbs allocated from skbuff_fclone_cache are used in the
socket error queue, accessing the sock_exterr_skb structure in skb->cb
via put_cmsg() triggers a usercopy hardening violation:
[ 5.379589] usercopy: Kernel memory exposure attempt detected from SLUB object 'skbuff_fclone_cache' (offset 296, size 16)!
[ 5.382796] kernel BUG at mm/usercopy.c:102!
[ 5.383923] Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI
[ 5.384903] CPU: 1 UID: 0 PID: 138 Comm: poc_put_cmsg Not tainted 6.12.57 #7
[ 5.384903] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[ 5.384903] RIP: 0010:usercopy_abort+0x6c/0x80
[ 5.384903] Code: 1a 86 51 48 c7 c2 40 15 1a 86 41 52 48 c7 c7 c0 15 1a 86 48 0f 45 d6 48 c7 c6 80 15 1a 86 48 89 c1 49 0f 45 f3 e8 84 27 88 ff <0f> 0b 490
[ 5.384903] RSP: 0018:ffffc900006f77a8 EFLAGS: 00010246
[ 5.384903] RAX: 000000000000006f RBX: ffff88800f0ad2a8 RCX: 1ffffffff0f72e74
[ 5.384903] RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffffff87b973a0
[ 5.384903] RBP: 0000000000000010 R08: 0000000000000000 R09: fffffbfff0f72e74
[ 5.384903] R10: 0000000000000003 R11: 79706f6372657375 R12: 0000000000000001
[ 5.384903] R13: ffff88800f0ad2b8 R14: ffffea00003c2b40 R15: ffffea00003c2b00
[ 5.384903] FS: 0000000011bc4380(0000) GS:ffff8880bf100000(0000) knlGS:0000000000000000
[ 5.384903] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 5.384903] CR2: 000056aa3b8e5fe4 CR3: 000000000ea26004 CR4: 0000000000770ef0
[ 5.384903] PKRU: 55555554
[ 5.384903] Call Trace:
[ 5.384903] <TASK>
[ 5.384903] __check_heap_object+0x9a/0xd0
[ 5.384903] __check_object_size+0x46c/0x690
[ 5.384903] put_cmsg+0x129/0x5e0
[ 5.384903] sock_recv_errqueue+0x22f/0x380
[ 5.384903] tls_sw_recvmsg+0x7ed/0x1960
[ 5.384903] ? srso_alias_return_thunk+0x5/0xfbef5
[ 5.384903] ? schedule+0x6d/0x270
[ 5.384903] ? srso_alias_return_thunk+0x5/0xfbef5
[ 5.384903] ? mutex_unlock+0x81/0xd0
[ 5.384903] ? __pfx_mutex_unlock+0x10/0x10
[ 5.384903] ? __pfx_tls_sw_recvmsg+0x10/0x10
[ 5.384903] ? _raw_spin_lock_irqsave+0x8f/0xf0
[ 5.384903] ? _raw_read_unlock_irqrestore+0x20/0x40
[ 5.384903] ? srso_alias_return_thunk+0x5/0xfbef5
The crash offset 296 corresponds to skb2->cb within skbuff_fclones:
- sizeof(struct sk_buff) = 232 - offsetof(struct sk_buff, cb) = 40 -
offset of skb2.cb in fclones = 232 + 40 = 272 - crash offset 296 =
272 + 24 (inside sock_exterr_skb.ee)
This patch uses a local stack variable as a bounce buffer to avoid the hardened usercopy check failure.
[1] https://elixir.bootlin.com/linux/v6.12.62/source/net/ipv4/tcp.c#L885
[2] https://elixir.bootlin.com/linux/v6.12.62/source/net/core/skbuff.c#L5104
[3] https://elixir.bootlin.com/linux/v6.12.62/source/net/core/skbuff.c#L5566
[4] https://elixir.bootlin.com/linux/v6.12.62/source/net/core/skbuff.c#L5491
[5] https://elixir.bootlin.com/linux/v6.12.62/source/mm/slub.c#L5719
CVSS Score
5.5
EPSS Score
0.0
Published
2026-01-21
In the Linux kernel, the following vulnerability has been resolved:
net/sched: sch_qfq: Fix NULL deref when deactivating inactive aggregate in qfq_reset
`qfq_class->leaf_qdisc->q.qlen > 0` does not imply that the class
itself is active.
Two qfq_class objects may point to the same leaf_qdisc. This happens
when:
1. one QFQ qdisc is attached to the dev as the root qdisc, and
2. another QFQ qdisc is temporarily referenced (e.g., via qdisc_get()
/ qdisc_put()) and is pending to be destroyed, as in function
tc_new_tfilter.
When packets are enqueued through the root QFQ qdisc, the shared
leaf_qdisc->q.qlen increases. At the same time, the second QFQ
qdisc triggers qdisc_put and qdisc_destroy: the qdisc enters
qfq_reset() with its own q->q.qlen == 0, but its class's leaf
qdisc->q.qlen > 0. Therefore, the qfq_reset would wrongly deactivate
an inactive aggregate and trigger a null-deref in qfq_deactivate_agg:
[ 0.903172] BUG: kernel NULL pointer dereference, address: 0000000000000000
[ 0.903571] #PF: supervisor write access in kernel mode
[ 0.903860] #PF: error_code(0x0002) - not-present page
[ 0.904177] PGD 10299b067 P4D 10299b067 PUD 10299c067 PMD 0
[ 0.904502] Oops: Oops: 0002 [#1] SMP NOPTI
[ 0.904737] CPU: 0 UID: 0 PID: 135 Comm: exploit Not tainted 6.19.0-rc3+ #2 NONE
[ 0.905157] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.17.0-0-gb52ca86e094d-prebuilt.qemu.org 04/01/2014
[ 0.905754] RIP: 0010:qfq_deactivate_agg (include/linux/list.h:992 (discriminator 2) include/linux/list.h:1006 (discriminator 2) net/sched/sch_qfq.c:1367 (discriminator 2) net/sched/sch_qfq.c:1393 (discriminator 2))
[ 0.906046] Code: 0f 84 4d 01 00 00 48 89 70 18 8b 4b 10 48 c7 c2 ff ff ff ff 48 8b 78 08 48 d3 e2 48 21 f2 48 2b 13 48 8b 30 48 d3 ea 8b 4b 18 0
Code starting with the faulting instruction
===========================================
0: 0f 84 4d 01 00 00 je 0x153
6: 48 89 70 18 mov %rsi,0x18(%rax)
a: 8b 4b 10 mov 0x10(%rbx),%ecx
d: 48 c7 c2 ff ff ff ff mov $0xffffffffffffffff,%rdx
14: 48 8b 78 08 mov 0x8(%rax),%rdi
18: 48 d3 e2 shl %cl,%rdx
1b: 48 21 f2 and %rsi,%rdx
1e: 48 2b 13 sub (%rbx),%rdx
21: 48 8b 30 mov (%rax),%rsi
24: 48 d3 ea shr %cl,%rdx
27: 8b 4b 18 mov 0x18(%rbx),%ecx
...
[ 0.907095] RSP: 0018:ffffc900004a39a0 EFLAGS: 00010246
[ 0.907368] RAX: ffff8881043a0880 RBX: ffff888102953340 RCX: 0000000000000000
[ 0.907723] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
[ 0.908100] RBP: ffff888102952180 R08: 0000000000000000 R09: 0000000000000000
[ 0.908451] R10: ffff8881043a0000 R11: 0000000000000000 R12: ffff888102952000
[ 0.908804] R13: ffff888102952180 R14: ffff8881043a0ad8 R15: ffff8881043a0880
[ 0.909179] FS: 000000002a1a0380(0000) GS:ffff888196d8d000(0000) knlGS:0000000000000000
[ 0.909572] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 0.909857] CR2: 0000000000000000 CR3: 0000000102993002 CR4: 0000000000772ef0
[ 0.910247] PKRU: 55555554
[ 0.910391] Call Trace:
[ 0.910527] <TASK>
[ 0.910638] qfq_reset_qdisc (net/sched/sch_qfq.c:357 net/sched/sch_qfq.c:1485)
[ 0.910826] qdisc_reset (include/linux/skbuff.h:2195 include/linux/skbuff.h:2501 include/linux/skbuff.h:3424 include/linux/skbuff.h:3430 net/sched/sch_generic.c:1036)
[ 0.911040] __qdisc_destroy (net/sched/sch_generic.c:1076)
[ 0.911236] tc_new_tfilter (net/sched/cls_api.c:2447)
[ 0.911447] rtnetlink_rcv_msg (net/core/rtnetlink.c:6958)
[ 0.911663] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6861)
[ 0.911894] netlink_rcv_skb (net/netlink/af_netlink.c:2550)
[ 0.912100] netlink_unicast (net/netlink/af_netlink.c:1319 net/netlink/af_netlink.c:1344)
[ 0.912296] ? __alloc_skb (net/core/skbuff.c:706)
[ 0.912484] netlink_sendmsg (net/netlink/af
---truncated---
CVSS Score
5.5
EPSS Score
0.0
Published
2026-01-21
In the Linux kernel, the following vulnerability has been resolved:
media: adv7842: Avoid possible out-of-bounds array accesses in adv7842_cp_log_status()
It's possible for cp_read() and hdmi_read() to return -EIO. Those
values are further used as indexes for accessing arrays.
Fix that by checking return values where it's needed.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
CVSS Score
7.1
EPSS Score
0.0
Published
2026-01-14
In the Linux kernel, the following vulnerability has been resolved:
crypto: seqiv - Do not use req->iv after crypto_aead_encrypt
As soon as crypto_aead_encrypt is called, the underlying request
may be freed by an asynchronous completion. Thus dereferencing
req->iv after it returns is invalid.
Instead of checking req->iv against info, create a new variable
unaligned_info and use it for that purpose instead.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-01-14
In the Linux kernel, the following vulnerability has been resolved:
via_wdt: fix critical boot hang due to unnamed resource allocation
The VIA watchdog driver uses allocate_resource() to reserve a MMIO
region for the watchdog control register. However, the allocated
resource was not given a name, which causes the kernel resource tree
to contain an entry marked as "<BAD>" under /proc/iomem on x86
platforms.
During boot, this unnamed resource can lead to a critical hang because
subsequent resource lookups and conflict checks fail to handle the
invalid entry properly.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-01-14
In the Linux kernel, the following vulnerability has been resolved:
libceph: make decode_pool() more resilient against corrupted osdmaps
If the osdmap is (maliciously) corrupted such that the encoded length
of ceph_pg_pool envelope is less than what is expected for a particular
encoding version, out-of-bounds reads may ensue because the only bounds
check that is there is based on that length value.
This patch adds explicit bounds checks for each field that is decoded
or skipped.
CVSS Score
7.1
EPSS Score
0.0
Published
2026-01-14
In the Linux kernel, the following vulnerability has been resolved:
ACPICA: Avoid walking the Namespace if start_node is NULL
Although commit 0c9992315e73 ("ACPICA: Avoid walking the ACPI Namespace
if it is not there") fixed the situation when both start_node and
acpi_gbl_root_node are NULL, the Linux kernel mainline now still crashed
on Honor Magicbook 14 Pro [1].
That happens due to the access to the member of parent_node in
acpi_ns_get_next_node(). The NULL pointer dereference will always
happen, no matter whether or not the start_node is equal to
ACPI_ROOT_OBJECT, so move the check of start_node being NULL
out of the if block.
Unfortunately, all the attempts to contact Honor have failed, they
refused to provide any technical support for Linux.
The bad DSDT table's dump could be found on GitHub [2].
DMI: HONOR FMB-P/FMB-P-PCB, BIOS 1.13 05/08/2025
[ rjw: Subject adjustment, changelog edits ]
CVSS Score
5.5
EPSS Score
0.0
Published
2026-01-14
In the Linux kernel, the following vulnerability has been resolved:
hwmon: (w83791d) Convert macros to functions to avoid TOCTOU
The macro FAN_FROM_REG evaluates its arguments multiple times. When used
in lockless contexts involving shared driver data, this leads to
Time-of-Check to Time-of-Use (TOCTOU) race conditions, potentially
causing divide-by-zero errors.
Convert the macro to a static function. This guarantees that arguments
are evaluated only once (pass-by-value), preventing the race
conditions.
Additionally, in store_fan_div, move the calculation of the minimum
limit inside the update lock. This ensures that the read-modify-write
sequence operates on consistent data.
Adhere to the principle of minimal changes by only converting macros
that evaluate arguments multiple times and are used in lockless
contexts.
CVSS Score
4.7
EPSS Score
0.0
Published
2026-01-14
In the Linux kernel, the following vulnerability has been resolved:
crypto: af_alg - zero initialize memory allocated via sock_kmalloc
Several crypto user API contexts and requests allocated with
sock_kmalloc() were left uninitialized, relying on callers to
set fields explicitly. This resulted in the use of uninitialized
data in certain error paths or when new fields are added in the
future.
The ACVP patches also contain two user-space interface files:
algif_kpp.c and algif_akcipher.c. These too rely on proper
initialization of their context structures.
A particular issue has been observed with the newly added
'inflight' variable introduced in af_alg_ctx by commit:
67b164a871af ("crypto: af_alg - Disallow multiple in-flight AIO requests")
Because the context is not memset to zero after allocation,
the inflight variable has contained garbage values. As a result,
af_alg_alloc_areq() has incorrectly returned -EBUSY randomly when
the garbage value was interpreted as true:
https://github.com/gregkh/linux/blame/master/crypto/af_alg.c#L1209
The check directly tests ctx->inflight without explicitly
comparing against true/false. Since inflight is only ever set to
true or false later, an uninitialized value has triggered
-EBUSY failures. Zero-initializing memory allocated with
sock_kmalloc() ensures inflight and other fields start in a known
state, removing random issues caused by uninitialized data.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-01-14
In the Linux kernel, the following vulnerability has been resolved:
usb: typec: ucsi: Handle incorrect num_connectors capability
The UCSI spec states that the num_connectors field is 7 bits, and the
8th bit is reserved and should be set to zero.
Some buggy FW has been known to set this bit, and it can lead to a
system not booting.
Flag that the FW is not behaving correctly, and auto-fix the value
so that the system boots correctly.
Found on Lenovo P1 G8 during Linux enablement program. The FW will
be fixed, but seemed worth addressing in case it hit platforms that
aren't officially Linux supported.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-01-14