CVE-2025-38165
MediumIn 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.
CVSS 3.1 score
5.5
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Weakness type
CWE-401CVE-2025-38165 is a Memory Leak vulnerability
What is Memory Leak?
The product does not release memory after use, causing gradual resource exhaustion. Learn more on MITRE CWE
Affected versions
Linux kernel versions
5.15.189,
6.1.54,
6.5.4,
6.6
and later are affected. Fixed in
5.15.190,
6.1.142,
6.6.94,
6.12.34,
6.15.3,
6.16
and their respective stable series.
References
The following references provide additional information about CVE-2025-38165 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.
-
Third Party Advisory
-
PatchKernel patch commithttps://git.kernel.org/stable/c/3d25fa2d7f127348c818e1dab9e58534f7ac56cc
-
PatchKernel patch commithttps://git.kernel.org/stable/c/4dba44333a11522df54b49aa1f2edfaf6ce35fc7
-
PatchKernel patch commithttps://git.kernel.org/stable/c/5ca2e29f6834c64c0e5a9ccf1278c21fb49b827e
Frequently asked questions
-
What is CVE-2025-38165?
CVE-2025-38165 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 , classified as a Memory Leak flaw (CWE-401) . It affects Linux kernel versions from 5.15.189 onward and has been patched in 5.15.190, 6.1.142, 6.6.94 and others. CVE-2025-38165 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
-
What is the CVSS score for CVE-2025-38165?
CVE-2025-38165 has a CVSS score of 5.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H. -
Is there a patch available for CVE-2025-38165?
Yes — CVE-2025-38165 has been patched. Fixed versions include 5.15.190, 6.1.142, 6.6.94 and others. If you are running Linux kernel 5.15.189 or later up to the fix versions, apply the relevant patch for your kernel branch.
-
Is CVE-2025-38165 actively exploited?
No — CVE-2025-38165 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.
-
What is Memory Leak (CWE-401)?
The product does not release memory after use, causing gradual resource exhaustion. View CWE-401 on MITRE CWE →