In the Linux kernel, the following vulnerability has been resolved:
bpf, sockmap: Fix panic when calling skb_linearize
The panic can be reproduced by executing the command:
./bench sockmap -c 2 -p 1 -a --rx-verdict-ingress --rx-strp 100000
Then a kernel panic was captured:
'''
[ 657.460555] kernel BUG at net/core/skbuff.c:2178!
[ 657.462680] Tainted: [W]=WARN
[ 657.463287] Workqueue: events sk_psock_backlog
...
[ 657.469610] <TASK>
[ 657.469738] ? die+0x36/0x90
[ 657.469916] ? do_trap+0x1d0/0x270
[ 657.470118] ? pskb_expand_head+0x612/0xf40
[ 657.470376] ? pskb_expand_head+0x612/0xf40
[ 657.470620] ? do_error_trap+0xa3/0x170
[ 657.470846] ? pskb_expand_head+0x612/0xf40
[ 657.471092] ? handle_invalid_op+0x2c/0x40
[ 657.471335] ? pskb_expand_head+0x612/0xf40
[ 657.471579] ? exc_invalid_op+0x2d/0x40
[ 657.471805] ? asm_exc_invalid_op+0x1a/0x20
[ 657.472052] ? pskb_expand_head+0xd1/0xf40
[ 657.472292] ? pskb_expand_head+0x612/0xf40
[ 657.472540] ? lock_acquire+0x18f/0x4e0
[ 657.472766] ? find_held_lock+0x2d/0x110
[ 657.472999] ? __pfx_pskb_expand_head+0x10/0x10
[ 657.473263] ? __kmalloc_cache_noprof+0x5b/0x470
[ 657.473537] ? __pfx___lock_release.isra.0+0x10/0x10
[ 657.473826] __pskb_pull_tail+0xfd/0x1d20
[ 657.474062] ? __kasan_slab_alloc+0x4e/0x90
[ 657.474707] sk_psock_skb_ingress_enqueue+0x3bf/0x510
[ 657.475392] ? __kasan_kmalloc+0xaa/0xb0
[ 657.476010] sk_psock_backlog+0x5cf/0xd70
[ 657.476637] process_one_work+0x858/0x1a20
'''
The panic originates from the assertion BUG_ON(skb_shared(skb)) in
skb_linearize(). A previous commit(see Fixes tag) introduced skb_get()
to avoid race conditions between skb operations in the backlog and skb
release in the recvmsg path. However, this caused the panic to always
occur when skb_linearize is executed.
The "--rx-strp 100000" parameter forces the RX path to use the strparser
module which aggregates data until it reaches 100KB before calling sockmap
logic. The 100KB payload exceeds MAX_MSG_FRAGS, triggering skb_linearize.
To fix this issue, just move skb_get into sk_psock_skb_ingress_enqueue.
'''
sk_psock_backlog:
sk_psock_handle_skb
skb_get(skb) <== we move it into 'sk_psock_skb_ingress_enqueue'
sk_psock_skb_ingress____________
↓
|
| → sk_psock_skb_ingress_self
| sk_psock_skb_ingress_enqueue
sk_psock_verdict_apply_________________↑ skb_linearize
'''
Note that for verdict_apply path, the skb_get operation is unnecessary so
we add 'take_ref' param to control it's behavior.
References
Configurations
Configuration 1 (hide)
|
Configuration 2 (hide)
|
History
18 Dec 2025, 20:51
| Type | Values Removed | Values Added |
|---|---|---|
| CWE | CWE-401 | |
| CPE | cpe:2.3:o:linux:linux_kernel:5.15.189:*:*:*:*:*:*:* cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
|
| CVSS |
v2 : v3 : |
v2 : unknown
v3 : 5.5 |
| References | () https://git.kernel.org/stable/c/3d25fa2d7f127348c818e1dab9e58534f7ac56cc - Patch | |
| References | () https://git.kernel.org/stable/c/4dba44333a11522df54b49aa1f2edfaf6ce35fc7 - Patch | |
| References | () https://git.kernel.org/stable/c/5ca2e29f6834c64c0e5a9ccf1278c21fb49b827e - Patch | |
| References | () https://git.kernel.org/stable/c/9718ba6490732dbe70190d42c21deb1440834402 - Patch | |
| References | () https://git.kernel.org/stable/c/db1d15a26f21f97459508c42ae87cabe8d3afc3b - Patch | |
| References | () https://git.kernel.org/stable/c/e9c1299d813fc04668042690f2c3cc76d013959a - Patch | |
| References | () https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html - Third Party Advisory | |
| First Time |
Linux
Debian Debian debian Linux Linux linux Kernel |
03 Nov 2025, 18:16
| Type | Values Removed | Values Added |
|---|---|---|
| References |
|
28 Aug 2025, 15:15
| Type | Values Removed | Values Added |
|---|---|---|
| References |
|
|
| Summary | (es) En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: bpf, sockmap: Se corrige el pánico al llamar a skb_linearize El pánico se puede reproducir ejecutando el comando: ./bench sockmap -c 2 -p 1 -a --rx-verdict-ingress --rx-strp 100000 Luego se capturó un pánico del kernel: ''' [ 657.460555] kernel BUG at net/core/skbuff.c:2178! [ 657.462680] Tainted: [W]=WARN [ 657.463287] Workqueue: events sk_psock_backlog ... [ 657.469610] [ 657.469738] ? die+0x36/0x90 [ 657.469916] ? do_trap+0x1d0/0x270 [ 657.470118] ? pskb_expand_head+0x612/0xf40 [ 657.470376] ? pskb_expand_head+0x612/0xf40 [ 657.470620] ? do_error_trap+0xa3/0x170 [ 657.470846] ? pskb_expand_head+0x612/0xf40 [ 657.471092] ? handle_invalid_op+0x2c/0x40 [ 657.471335] ? pskb_expand_head+0x612/0xf40 [ 657.471579] ? exc_invalid_op+0x2d/0x40 [ 657.471805] ? asm_exc_invalid_op+0x1a/0x20 [ 657.472052] ? pskb_expand_head+0xd1/0xf40 [ 657.472292] ? pskb_expand_head+0x612/0xf40 [ 657.472540] ? lock_acquire+0x18f/0x4e0 [ 657.472766] ? find_held_lock+0x2d/0x110 [ 657.472999] ? __pfx_pskb_expand_head+0x10/0x10 [ 657.473263] ? __kmalloc_cache_noprof+0x5b/0x470 [ 657.473537] ? __pfx___lock_release.isra.0+0x10/0x10 [ 657.473826] __pskb_pull_tail+0xfd/0x1d20 [ 657.474062] ? __kasan_slab_alloc+0x4e/0x90 [ 657.474707] sk_psock_skb_ingress_enqueue+0x3bf/0x510 [ 657.475392] ? __kasan_kmalloc+0xaa/0xb0 [ 657.476010] sk_psock_backlog+0x5cf/0xd70 [ 657.476637] process_one_work+0x858/0x1a20 ''' El pánico se origina en la aserción BUG_ON(skb_shared(skb)) en skb_linearize(). Una confirmación anterior (véase la etiqueta "Correcciones") introdujo skb_get() para evitar condiciones de ejecución entre las operaciones de skb en el backlog y la versión de skb en la ruta recvmsg. Sin embargo, esto provocaba que el pánico siempre se produjera al ejecutar skb_linearize. El parámetro "--rx-strp 100000" obliga a la ruta RX a usar el módulo strparser, que agrega datos hasta alcanzar los 100 KB antes de llamar a la lógica de sockmap. El payload de 100 KB supera MAX_MSG_FRAGS, lo que activa skb_linearize. Para solucionar este problema, simplemente mueva skb_get a sk_psock_skb_ingress_enqueue. ''' sk_psock_backlog: sk_psock_handle_skb skb_get(skb) <== lo movemos a 'sk_psock_skb_ingress_enqueue' sk_psock_skb_ingress____________ ? | | ? sk_psock_skb_ingress_self | sk_psock_skb_ingress_enqueue sk_psock_verdict_apply_________________? skb_linearize ''' Tenga en cuenta que para la ruta verdict_apply, la operación skb_get es innecesaria, por lo que añadimos el parámetro 'take_ref' para controlar su comportamiento. |
03 Jul 2025, 15:13
| Type | Values Removed | Values Added |
|---|---|---|
| Summary |
|
03 Jul 2025, 09:15
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2025-07-03 09:15
Updated : 2025-12-18 20:51
NVD link : CVE-2025-38165
Mitre link : CVE-2025-38165
CVE.ORG link : CVE-2025-38165
JSON object : View
Products Affected
debian
- debian_linux
linux
- linux_kernel
CWE
CWE-401
Missing Release of Memory after Effective Lifetime
