Linux: >> Linux Kernel >> 5.16.20 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
xfrm: Zero padding when dumping algos and encap
When copying data to user-space we should ensure that only valid
data is copied over. Padding in structures may be filled with
random (possibly sensitve) data and should never be given directly
to user-space.
This patch fixes the copying of xfrm algorithms and the encap
template in xfrm_user so that padding is zeroed.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-07
In the Linux kernel, the following vulnerability has been resolved:
tun: Fix memory leak for detached NAPI queue.
syzkaller reported [0] memory leaks of sk and skb related to the TUN
device with no repro, but we can reproduce it easily with:
struct ifreq ifr = {}
int fd_tun, fd_tmp;
char buf[4] = {};
fd_tun = openat(AT_FDCWD, "/dev/net/tun", O_WRONLY, 0);
ifr.ifr_flags = IFF_TUN | IFF_NAPI | IFF_MULTI_QUEUE;
ioctl(fd_tun, TUNSETIFF, &ifr);
ifr.ifr_flags = IFF_DETACH_QUEUE;
ioctl(fd_tun, TUNSETQUEUE, &ifr);
fd_tmp = socket(AF_PACKET, SOCK_PACKET, 0);
ifr.ifr_flags = IFF_UP;
ioctl(fd_tmp, SIOCSIFFLAGS, &ifr);
write(fd_tun, buf, sizeof(buf));
close(fd_tun);
If we enable NAPI and multi-queue on a TUN device, we can put skb into
tfile->sk.sk_write_queue after the queue is detached. We should prevent
it by checking tfile->detached before queuing skb.
Note this must be done under tfile->sk.sk_write_queue.lock because write()
and ioctl(IFF_DETACH_QUEUE) can run concurrently. Otherwise, there would
be a small race window:
write() ioctl(IFF_DETACH_QUEUE)
`- tun_get_user `- __tun_detach
|- if (tfile->detached) |- tun_disable_queue
| `-> false | `- tfile->detached = tun
| `- tun_queue_purge
|- spin_lock_bh(&queue->lock)
`- __skb_queue_tail(queue, skb)
Another solution is to call tun_queue_purge() when closing and
reattaching the detached queue, but it could paper over another
problems. Also, we do the same kind of test for IFF_NAPI_FRAGS.
[0]:
unreferenced object 0xffff88801edbc800 (size 2048):
comm "syz-executor.1", pid 33269, jiffies 4295743834 (age 18.756s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 07 40 00 00 00 00 00 00 00 00 00 00 00 00 ...@............
backtrace:
[<000000008c16ea3d>] __do_kmalloc_node mm/slab_common.c:965 [inline]
[<000000008c16ea3d>] __kmalloc+0x4a/0x130 mm/slab_common.c:979
[<000000003addde56>] kmalloc include/linux/slab.h:563 [inline]
[<000000003addde56>] sk_prot_alloc+0xef/0x1b0 net/core/sock.c:2035
[<000000003e20621f>] sk_alloc+0x36/0x2f0 net/core/sock.c:2088
[<0000000028e43843>] tun_chr_open+0x3d/0x190 drivers/net/tun.c:3438
[<000000001b0f1f28>] misc_open+0x1a6/0x1f0 drivers/char/misc.c:165
[<000000004376f706>] chrdev_open+0x111/0x300 fs/char_dev.c:414
[<00000000614d379f>] do_dentry_open+0x2f9/0x750 fs/open.c:920
[<000000008eb24774>] do_open fs/namei.c:3636 [inline]
[<000000008eb24774>] path_openat+0x143f/0x1a30 fs/namei.c:3791
[<00000000955077b5>] do_filp_open+0xce/0x1c0 fs/namei.c:3818
[<00000000b78973b0>] do_sys_openat2+0xf0/0x260 fs/open.c:1356
[<00000000057be699>] do_sys_open fs/open.c:1372 [inline]
[<00000000057be699>] __do_sys_openat fs/open.c:1388 [inline]
[<00000000057be699>] __se_sys_openat fs/open.c:1383 [inline]
[<00000000057be699>] __x64_sys_openat+0x83/0xf0 fs/open.c:1383
[<00000000a7d2182d>] do_syscall_x64 arch/x86/entry/common.c:50 [inline]
[<00000000a7d2182d>] do_syscall_64+0x3c/0x90 arch/x86/entry/common.c:80
[<000000004cc4e8c4>] entry_SYSCALL_64_after_hwframe+0x72/0xdc
unreferenced object 0xffff88802f671700 (size 240):
comm "syz-executor.1", pid 33269, jiffies 4295743854 (age 18.736s)
hex dump (first 32 bytes):
68 c9 db 1e 80 88 ff ff 68 c9 db 1e 80 88 ff ff h.......h.......
00 c0 7b 2f 80 88 ff ff 00 c8 db 1e 80 88 ff ff ..{/............
backtrace:
[<00000000e9d9fdb6>] __alloc_skb+0x223/0x250 net/core/skbuff.c:644
[<000000002c3e4e0b>] alloc_skb include/linux/skbuff.h:1288 [inline]
[<000000002c3e4e0b>] alloc_skb_with_frags+0x6f/0x350 net/core/skbuff.c:6378
[<00000000825f98d7>] sock_alloc_send_pskb+0x3ac/0x3e0 net/core/sock.c:2729
[<00000000e9eb3df3>] tun_alloc_skb drivers/net/tun.c:1529 [inline]
[<
---truncated---
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-07
In the Linux kernel, the following vulnerability has been resolved:
btrfs: output extra debug info if we failed to find an inline backref
[BUG]
Syzbot reported several warning triggered inside
lookup_inline_extent_backref().
[CAUSE]
As usual, the reproducer doesn't reliably trigger locally here, but at
least we know the WARN_ON() is triggered when an inline backref can not
be found, and it can only be triggered when @insert is true. (I.e.
inserting a new inline backref, which means the backref should already
exist)
[ENHANCEMENT]
After the WARN_ON(), dump all the parameters and the extent tree
leaf to help debug.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-07
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: hci_event: call disconnect callback before deleting conn
In hci_cs_disconnect, we do hci_conn_del even if disconnection failed.
ISO, L2CAP and SCO connections refer to the hci_conn without
hci_conn_get, so disconn_cfm must be called so they can clean up their
conn, otherwise use-after-free occurs.
ISO:
==========================================================
iso_sock_connect:880: sk 00000000eabd6557
iso_connect_cis:356: 70:1a:b8:98:ff:a2 -> 28:3d:c2:4a:7e:da
...
iso_conn_add:140: hcon 000000001696f1fd conn 00000000b6251073
hci_dev_put:1487: hci0 orig refcnt 17
__iso_chan_add:214: conn 00000000b6251073
iso_sock_clear_timer:117: sock 00000000eabd6557 state 3
...
hci_rx_work:4085: hci0 Event packet
hci_event_packet:7601: hci0: event 0x0f
hci_cmd_status_evt:4346: hci0: opcode 0x0406
hci_cs_disconnect:2760: hci0: status 0x0c
hci_sent_cmd_data:3107: hci0 opcode 0x0406
hci_conn_del:1151: hci0 hcon 000000001696f1fd handle 2560
hci_conn_unlink:1102: hci0: hcon 000000001696f1fd
hci_conn_drop:1451: hcon 00000000d8521aaf orig refcnt 2
hci_chan_list_flush:2780: hcon 000000001696f1fd
hci_dev_put:1487: hci0 orig refcnt 21
hci_dev_put:1487: hci0 orig refcnt 20
hci_req_cmd_complete:3978: opcode 0x0406 status 0x0c
... <no iso_* activity on sk/conn> ...
iso_sock_sendmsg:1098: sock 00000000dea5e2e0, sk 00000000eabd6557
BUG: kernel NULL pointer dereference, address: 0000000000000668
PGD 0 P4D 0
Oops: 0000 [#1] PREEMPT SMP PTI
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-1.fc38 04/01/2014
RIP: 0010:iso_sock_sendmsg (net/bluetooth/iso.c:1112) bluetooth
==========================================================
L2CAP:
==================================================================
hci_cmd_status_evt:4359: hci0: opcode 0x0406
hci_cs_disconnect:2760: hci0: status 0x0c
hci_sent_cmd_data:3085: hci0 opcode 0x0406
hci_conn_del:1151: hci0 hcon ffff88800c999000 handle 3585
hci_conn_unlink:1102: hci0: hcon ffff88800c999000
hci_chan_list_flush:2780: hcon ffff88800c999000
hci_chan_del:2761: hci0 hcon ffff88800c999000 chan ffff888018ddd280
...
BUG: KASAN: slab-use-after-free in hci_send_acl+0x2d/0x540 [bluetooth]
Read of size 8 at addr ffff888018ddd298 by task bluetoothd/1175
CPU: 0 PID: 1175 Comm: bluetoothd Tainted: G E 6.4.0-rc4+ #2
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-1.fc38 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x5b/0x90
print_report+0xcf/0x670
? __virt_addr_valid+0xf8/0x180
? hci_send_acl+0x2d/0x540 [bluetooth]
kasan_report+0xa8/0xe0
? hci_send_acl+0x2d/0x540 [bluetooth]
hci_send_acl+0x2d/0x540 [bluetooth]
? __pfx___lock_acquire+0x10/0x10
l2cap_chan_send+0x1fd/0x1300 [bluetooth]
? l2cap_sock_sendmsg+0xf2/0x170 [bluetooth]
? __pfx_l2cap_chan_send+0x10/0x10 [bluetooth]
? lock_release+0x1d5/0x3c0
? mark_held_locks+0x1a/0x90
l2cap_sock_sendmsg+0x100/0x170 [bluetooth]
sock_write_iter+0x275/0x280
? __pfx_sock_write_iter+0x10/0x10
? __pfx___lock_acquire+0x10/0x10
do_iter_readv_writev+0x176/0x220
? __pfx_do_iter_readv_writev+0x10/0x10
? find_held_lock+0x83/0xa0
? selinux_file_permission+0x13e/0x210
do_iter_write+0xda/0x340
vfs_writev+0x1b4/0x400
? __pfx_vfs_writev+0x10/0x10
? __seccomp_filter+0x112/0x750
? populate_seccomp_data+0x182/0x220
? __fget_light+0xdf/0x100
? do_writev+0x19d/0x210
do_writev+0x19d/0x210
? __pfx_do_writev+0x10/0x10
? mark_held_locks+0x1a/0x90
do_syscall_64+0x60/0x90
? lockdep_hardirqs_on_prepare+0x149/0x210
? do_syscall_64+0x6c/0x90
? lockdep_hardirqs_on_prepare+0x149/0x210
entry_SYSCALL_64_after_hwframe+0x72/0xdc
RIP: 0033:0x7ff45cb23e64
Code: 15 d1 1f 0d 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b8 0f 1f 00 f3 0f 1e fa 80 3d 9d a7 0d 00 00 74 13 b8 14 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 c3 0f 1f 00 48 83 ec 28 89 54 24 1c 48 89
RSP: 002b:00007fff21ae09b8 EFLAGS: 00000202 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX:
---truncated---
CVSS Score
7.8
EPSS Score
0.0
Published
2025-10-07
In the Linux kernel, the following vulnerability has been resolved:
clk: Fix memory leak in devm_clk_notifier_register()
devm_clk_notifier_register() allocates a devres resource for clk
notifier but didn't register that to the device, so the notifier didn't
get unregistered on device detach and the allocated resource was leaked.
Fix the issue by registering the resource through devres_add().
This issue was found with kmemleak on a Chromebook.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-07
In the Linux kernel, the following vulnerability has been resolved:
scsi: ses: Fix possible desc_ptr out-of-bounds accesses
Sanitize possible desc_ptr out-of-bounds accesses in
ses_enclosure_data_process().
CVSS Score
7.1
EPSS Score
0.0
Published
2025-10-07
In the Linux kernel, the following vulnerability has been resolved:
scsi: target: iscsi: Fix buffer overflow in lio_target_nacl_info_show()
The function lio_target_nacl_info_show() uses sprintf() in a loop to print
details for every iSCSI connection in a session without checking for the
buffer length. With enough iSCSI connections it's possible to overflow the
buffer provided by configfs and corrupt the memory.
This patch replaces sprintf() with sysfs_emit_at() that checks for buffer
boundries.
CVSS Score
7.8
EPSS Score
0.0
Published
2025-10-07
In the Linux kernel, the following vulnerability has been resolved:
KVM: nSVM: Check instead of asserting on nested TSC scaling support
Check for nested TSC scaling support on nested SVM VMRUN instead of
asserting that TSC scaling is exposed to L1 if L1's MSR_AMD64_TSC_RATIO
has diverged from KVM's default. Userspace can trigger the WARN at will
by writing the MSR and then updating guest CPUID to hide the feature
(modifying guest CPUID is allowed anytime before KVM_RUN). E.g. hacking
KVM's state_test selftest to do
vcpu_set_msr(vcpu, MSR_AMD64_TSC_RATIO, 0);
vcpu_clear_cpuid_feature(vcpu, X86_FEATURE_TSCRATEMSR);
after restoring state in a new VM+vCPU yields an endless supply of:
------------[ cut here ]------------
WARNING: CPU: 164 PID: 62565 at arch/x86/kvm/svm/nested.c:699
nested_vmcb02_prepare_control+0x3d6/0x3f0 [kvm_amd]
Call Trace:
<TASK>
enter_svm_guest_mode+0x114/0x560 [kvm_amd]
nested_svm_vmrun+0x260/0x330 [kvm_amd]
vmrun_interception+0x29/0x30 [kvm_amd]
svm_invoke_exit_handler+0x35/0x100 [kvm_amd]
svm_handle_exit+0xe7/0x180 [kvm_amd]
kvm_arch_vcpu_ioctl_run+0x1eab/0x2570 [kvm]
kvm_vcpu_ioctl+0x4c9/0x5b0 [kvm]
__se_sys_ioctl+0x7a/0xc0
__x64_sys_ioctl+0x21/0x30
do_syscall_64+0x41/0x90
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x45ca1b
Note, the nested #VMEXIT path has the same flaw, but needs a different
fix and will be handled separately.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-07
In the Linux kernel, the following vulnerability has been resolved:
ASoC: codecs: wcd938x: fix missing mbhc init error handling
MBHC initialisation can fail so add the missing error handling to avoid
dereferencing an error pointer when later configuring the jack:
Unable to handle kernel paging request at virtual address fffffffffffffff8
pc : wcd_mbhc_start+0x28/0x380 [snd_soc_wcd_mbhc]
lr : wcd938x_codec_set_jack+0x28/0x48 [snd_soc_wcd938x]
Call trace:
wcd_mbhc_start+0x28/0x380 [snd_soc_wcd_mbhc]
wcd938x_codec_set_jack+0x28/0x48 [snd_soc_wcd938x]
snd_soc_component_set_jack+0x28/0x8c [snd_soc_core]
qcom_snd_wcd_jack_setup+0x7c/0x19c [snd_soc_qcom_common]
sc8280xp_snd_init+0x20/0x2c [snd_soc_sc8280xp]
snd_soc_link_init+0x28/0x90 [snd_soc_core]
snd_soc_bind_card+0x628/0xbfc [snd_soc_core]
snd_soc_register_card+0xec/0x104 [snd_soc_core]
devm_snd_soc_register_card+0x4c/0xa4 [snd_soc_core]
sc8280xp_platform_probe+0xf0/0x108 [snd_soc_sc8280xp]
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-07
In the Linux kernel, the following vulnerability has been resolved:
net: cdc_ncm: Deal with too low values of dwNtbOutMaxSize
Currently in cdc_ncm_check_tx_max(), if dwNtbOutMaxSize is lower than
the calculated "min" value, but greater than zero, the logic sets
tx_max to dwNtbOutMaxSize. This is then used to allocate a new SKB in
cdc_ncm_fill_tx_frame() where all the data is handled.
For small values of dwNtbOutMaxSize the memory allocated during
alloc_skb(dwNtbOutMaxSize, GFP_ATOMIC) will have the same size, due to
how size is aligned at alloc time:
size = SKB_DATA_ALIGN(size);
size += SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
Thus we hit the same bug that we tried to squash with
commit 2be6d4d16a084 ("net: cdc_ncm: Allow for dwNtbOutMaxSize to be unset or zero")
Low values of dwNtbOutMaxSize do not cause an issue presently because at
alloc_skb() time more memory (512b) is allocated than required for the
SKB headers alone (320b), leaving some space (512b - 320b = 192b)
for CDC data (172b).
However, if more elements (for example 3 x u64 = [24b]) were added to
one of the SKB header structs, say 'struct skb_shared_info',
increasing its original size (320b [320b aligned]) to something larger
(344b [384b aligned]), then suddenly the CDC data (172b) no longer
fits in the spare SKB data area (512b - 384b = 128b).
Consequently the SKB bounds checking semantics fails and panics:
skbuff: skb_over_panic: text:ffffffff831f755b len:184 put:172 head:ffff88811f1c6c00 data:ffff88811f1c6c00 tail:0xb8 end:0x80 dev:<NULL>
------------[ cut here ]------------
kernel BUG at net/core/skbuff.c:113!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 57 Comm: kworker/0:2 Not tainted 5.15.106-syzkaller-00249-g19c0ed55a470 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023
Workqueue: mld mld_ifc_work
RIP: 0010:skb_panic net/core/skbuff.c:113 [inline]
RIP: 0010:skb_over_panic+0x14c/0x150 net/core/skbuff.c:118
[snip]
Call Trace:
<TASK>
skb_put+0x151/0x210 net/core/skbuff.c:2047
skb_put_zero include/linux/skbuff.h:2422 [inline]
cdc_ncm_ndp16 drivers/net/usb/cdc_ncm.c:1131 [inline]
cdc_ncm_fill_tx_frame+0x11ab/0x3da0 drivers/net/usb/cdc_ncm.c:1308
cdc_ncm_tx_fixup+0xa3/0x100
Deal with too low values of dwNtbOutMaxSize, clamp it in the range
[USB_CDC_NCM_NTB_MIN_OUT_SIZE, CDC_NCM_NTB_MAX_SIZE_TX]. We ensure
enough data space is allocated to handle CDC data by making sure
dwNtbOutMaxSize is not smaller than USB_CDC_NCM_NTB_MIN_OUT_SIZE.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-10-07