{"id":"CVE-2025-38165","url":"https://www.cyber-defence.io/tools/cve/CVE-2025-38165","generatedAt":"2026-10-28T06:14:48.056Z","title":"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…","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf, sockmap: Fix panic when calling skb_linearize\n\nThe panic can be reproduced by executing the command:\n./bench sockmap -c 2 -p 1 -a --rx-verdict-ingress --rx-strp 100000\n\nThen a kernel panic was captured:\n'''\n[  657.460555] kernel BUG at net/core/skbuff.c:2178!\n[  657.462680] Tainted: [W]=WARN\n[  657.463287] Workqueue: events sk_psock_backlog\n...\n[  657.469610]  <TASK>\n[  657.469738]  ? die+0x36/0x90\n[  657.469916]  ? do_trap+0x1d0/0x270\n[  657.470118]  ? pskb_expand_head+0x612/0xf40\n[  657.470376]  ? pskb_expand_head+0x612/0xf40\n[  657.470620]  ? do_error_trap+0xa3/0x170\n[  657.470846]  ? pskb_expand_head+0x612/0xf40\n[  657.471092]  ? handle_invalid_op+0x2c/0x40\n[  657.471335]  ? pskb_expand_head+0x612/0xf40\n[  657.471579]  ? exc_invalid_op+0x2d/0x40\n[  657.471805]  ? asm_exc_invalid_op+0x1a/0x20\n[  657.472052]  ? pskb_expand_head+0xd1/0xf40\n[  657.472292]  ? pskb_expand_head+0x612/0xf40\n[  657.472540]  ? lock_acquire+0x18f/0x4e0\n[  657.472766]  ? find_held_lock+0x2d/0x110\n[  657.472999]  ? __pfx_pskb_expand_head+0x10/0x10\n[  657.473263]  ? __kmalloc_cache_noprof+0x5b/0x470\n[  657.473537]  ? __pfx___lock_release.isra.0+0x10/0x10\n[  657.473826]  __pskb_pull_tail+0xfd/0x1d20\n[  657.474062]  ? __kasan_slab_alloc+0x4e/0x90\n[  657.474707]  sk_psock_skb_ingress_enqueue+0x3bf/0x510\n[  657.475392]  ? __kasan_kmalloc+0xaa/0xb0\n[  657.476010]  sk_psock_backlog+0x5cf/0xd70\n[  657.476637]  process_one_work+0x858/0x1a20\n'''\n\nThe panic originates from the assertion BUG_ON(skb_shared(skb)) in\nskb_linearize(). A previous commit(see Fixes tag) introduced skb_get()\nto avoid race conditions between skb operations in the backlog and skb\nrelease in the recvmsg path. However, this caused the panic to always\noccur when skb_linearize is executed.\n\nThe \"--rx-strp 100000\" parameter forces the RX path to use the strparser\nmodule which aggregates data until it reaches 100KB before calling sockmap\nlogic. The 100KB payload exceeds MAX_MSG_FRAGS, triggering skb_linearize.\n\nTo fix this issue, just move skb_get into sk_psock_skb_ingress_enqueue.\n\n'''\nsk_psock_backlog:\n    sk_psock_handle_skb\n       skb_get(skb) <== we move it into 'sk_psock_skb_ingress_enqueue'\n       sk_psock_skb_ingress____________\n                                       ↓\n                                       |\n                                       | → sk_psock_skb_ingress_self\n                                       |      sk_psock_skb_ingress_enqueue\nsk_psock_verdict_apply_________________↑          skb_linearize\n'''\n\nNote that for verdict_apply path, the skb_get operation is unnecessary so\nwe add 'take_ref' param to control it's behavior.","published":"2025-07-03T09:15:32.000Z","lastModified":"2026-07-30T06:22:56.000Z","status":"Modified","sourceIdentifier":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","cvss":{"version":"3.1","score":5.5,"severity":"MEDIUM","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"},"cwe":["CWE-401"],"affected":["linux/linux kernel","debian/debian linux"],"epss":{"score":0.0035,"percentile":0.28465,"date":"2026-10-27","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.35%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"https://git.kernel.org/stable/c/3d25fa2d7f127348c818e1dab9e58534f7ac56cc","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/4dba44333a11522df54b49aa1f2edfaf6ce35fc7","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/5ca2e29f6834c64c0e5a9ccf1278c21fb49b827e","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/9718ba6490732dbe70190d42c21deb1440834402","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/db1d15a26f21f97459508c42ae87cabe8d3afc3b","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/e9c1299d813fc04668042690f2c3cc76d013959a","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2025-38165","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}