{"id":"CVE-2025-21852","state":"PUBLISHED","title":"net: Add rx_skb of kfree_skb to raw_tp_null_args[].","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: Add rx_skb of kfree_skb to raw_tp_null_args[].\n\nYan Zhai reported a BPF prog could trigger a null-ptr-deref [0]\nin trace_kfree_skb if the prog does not check if rx_sk is NULL.\n\nCommit c53795d48ee8 (\"net: add rx_sk to trace_kfree_skb\") added\nrx_sk to trace_kfree_skb, but rx_sk is optional and could be NULL.\n\nLet's add kfree_skb to raw_tp_null_args[] to let the BPF verifier\nvalidate such a prog and prevent the issue.\n\nNow we fail to load such a prog:\n\n  libbpf: prog 'drop': -- BEGIN PROG LOAD LOG --\n  0: R1=ctx() R10=fp0\n  ; int BPF_PROG(drop, struct sk_buff *skb, void *location, @ kfree_skb_sk_null.bpf.c:21\n  0: (79) r3 = *(u64 *)(r1 +24)\n  func 'kfree_skb' arg3 has btf_id 5253 type STRUCT 'sock'\n  1: R1=ctx() R3_w=trusted_ptr_or_null_sock(id=1)\n  ; bpf_printk(\"sk: %d, %d\\n\", sk, sk->__sk_common.skc_family); @ kfree_skb_sk_null.bpf.c:24\n  1: (69) r4 = *(u16 *)(r3 +16)\n  R3 invalid mem access 'trusted_ptr_or_null_'\n  processed 2 insns (limit 1000000) max_states_per_insn 0 total_states 0 peak_states 0 mark_read 0\n  -- END PROG LOAD LOG --\n\nNote this fix requires commit 838a10bd2ebf (\"bpf: Augment raw_tp\narguments with PTR_MAYBE_NULL\").\n\n[0]:\nBUG: kernel NULL pointer dereference, address: 0000000000000010\n PF: supervisor read access in kernel mode\n PF: error_code(0x0000) - not-present page\nPGD 0 P4D 0\nPREEMPT SMP\nRIP: 0010:bpf_prog_5e21a6db8fcff1aa_drop+0x10/0x2d\nCall Trace:\n <TASK>\n ? __die+0x1f/0x60\n ? page_fault_oops+0x148/0x420\n ? search_bpf_extables+0x5b/0x70\n ? fixup_exception+0x27/0x2c0\n ? exc_page_fault+0x75/0x170\n ? asm_exc_page_fault+0x22/0x30\n ? bpf_prog_5e21a6db8fcff1aa_drop+0x10/0x2d\n bpf_trace_run4+0x68/0xd0\n ? unix_stream_connect+0x1f4/0x6f0\n sk_skb_reason_drop+0x90/0x120\n unix_stream_connect+0x1f4/0x6f0\n __sys_connect+0x7f/0xb0\n __x64_sys_connect+0x14/0x20\n do_syscall_64+0x47/0xc30\n entry_SYSCALL_64_after_hwframe+0x4b/0x53","publishedAt":"2025-03-12T09:42:07.175Z","updatedAt":"2026-05-11T21:07:45.279Z","severity":{"score":5.5,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","source":"CISA-ADP"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"c53795d48ee8f385c6a9e394651e7ee914baaeba","status":"affected","lessThan":"f579afacd0a66971fc8481f30d2d377e230a8342","versionType":"git"},{"version":"c53795d48ee8f385c6a9e394651e7ee914baaeba","status":"affected","lessThan":"4dba79c1e7aad6620bbb707b6c4459380fd90860","versionType":"git"},{"version":"c53795d48ee8f385c6a9e394651e7ee914baaeba","status":"affected","lessThan":"5da7e15fb5a12e78de974d8908f348e279922ce9","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/bpf/btf.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.11","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.11","versionType":"semver"},{"version":"6.12.17","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.13.5","status":"unaffected","lessThanOrEqual":"6.13.*","versionType":"semver"},{"version":"6.14","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/bpf/btf.c"]}],"references":["https://git.kernel.org/stable/c/f579afacd0a66971fc8481f30d2d377e230a8342","https://git.kernel.org/stable/c/4dba79c1e7aad6620bbb707b6c4459380fd90860","https://git.kernel.org/stable/c/5da7e15fb5a12e78de974d8908f348e279922ce9"],"weaknesses":["CWE-476"],"ingestedAt":"2026-10-29T20:08:39.238Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2025/21xxx/CVE-2025-21852.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2025-21852","state":"PUBLISHED","datePublished":"2025-03-12T09:42:07.175Z","dateUpdated":"2026-05-11T21:07:45.279Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2024-12-29T08:45:45.779Z"},"containers":{"cna":{"title":"net: Add rx_skb of kfree_skb to raw_tp_null_args[].","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: Add rx_skb of kfree_skb to raw_tp_null_args[].\n\nYan Zhai reported a BPF prog could trigger a null-ptr-deref [0]\nin trace_kfree_skb if the prog does not check if rx_sk is NULL.\n\nCommit c53795d48ee8 (\"net: add rx_sk to trace_kfree_skb\") added\nrx_sk to trace_kfree_skb, but rx_sk is optional and could be NULL.\n\nLet's add kfree_skb to raw_tp_null_args[] to let the BPF verifier\nvalidate such a prog and prevent the issue.\n\nNow we fail to load such a prog:\n\n  libbpf: prog 'drop': -- BEGIN PROG LOAD LOG --\n  0: R1=ctx() R10=fp0\n  ; int BPF_PROG(drop, struct sk_buff *skb, void *location, @ kfree_skb_sk_null.bpf.c:21\n  0: (79) r3 = *(u64 *)(r1 +24)\n  func 'kfree_skb' arg3 has btf_id 5253 type STRUCT 'sock'\n  1: R1=ctx() R3_w=trusted_ptr_or_null_sock(id=1)\n  ; bpf_printk(\"sk: %d, %d\\n\", sk, sk->__sk_common.skc_family); @ kfree_skb_sk_null.bpf.c:24\n  1: (69) r4 = *(u16 *)(r3 +16)\n  R3 invalid mem access 'trusted_ptr_or_null_'\n  processed 2 insns (limit 1000000) max_states_per_insn 0 total_states 0 peak_states 0 mark_read 0\n  -- END PROG LOAD LOG --\n\nNote this fix requires commit 838a10bd2ebf (\"bpf: Augment raw_tp\narguments with PTR_MAYBE_NULL\").\n\n[0]:\nBUG: kernel NULL pointer dereference, address: 0000000000000010\n PF: supervisor read access in kernel mode\n PF: error_code(0x0000) - not-present page\nPGD 0 P4D 0\nPREEMPT SMP\nRIP: 0010:bpf_prog_5e21a6db8fcff1aa_drop+0x10/0x2d\nCall Trace:\n <TASK>\n ? __die+0x1f/0x60\n ? page_fault_oops+0x148/0x420\n ? search_bpf_extables+0x5b/0x70\n ? fixup_exception+0x27/0x2c0\n ? exc_page_fault+0x75/0x170\n ? asm_exc_page_fault+0x22/0x30\n ? bpf_prog_5e21a6db8fcff1aa_drop+0x10/0x2d\n bpf_trace_run4+0x68/0xd0\n ? unix_stream_connect+0x1f4/0x6f0\n sk_skb_reason_drop+0x90/0x120\n unix_stream_connect+0x1f4/0x6f0\n __sys_connect+0x7f/0xb0\n __x64_sys_connect+0x14/0x20\n do_syscall_64+0x47/0xc30\n entry_SYSCALL_64_after_hwframe+0x4b/0x53"}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"c53795d48ee8f385c6a9e394651e7ee914baaeba","status":"affected","lessThan":"f579afacd0a66971fc8481f30d2d377e230a8342","versionType":"git"},{"version":"c53795d48ee8f385c6a9e394651e7ee914baaeba","status":"affected","lessThan":"4dba79c1e7aad6620bbb707b6c4459380fd90860","versionType":"git"},{"version":"c53795d48ee8f385c6a9e394651e7ee914baaeba","status":"affected","lessThan":"5da7e15fb5a12e78de974d8908f348e279922ce9","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/bpf/btf.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.11","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.11","versionType":"semver"},{"version":"6.12.17","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.13.5","status":"unaffected","lessThanOrEqual":"6.13.*","versionType":"semver"},{"version":"6.14","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/bpf/btf.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/f579afacd0a66971fc8481f30d2d377e230a8342"},{"url":"https://git.kernel.org/stable/c/4dba79c1e7aad6620bbb707b6c4459380fd90860"},{"url":"https://git.kernel.org/stable/c/5da7e15fb5a12e78de974d8908f348e279922ce9"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-05-11T21:07:45.279Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.11","versionEndExcluding":"6.12.17"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.11","versionEndExcluding":"6.13.5"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.11","versionEndExcluding":"6.14"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"cvssV3_1":{"scope":"UNCHANGED","version":"3.1","baseScore":5.5,"attackVector":"LOCAL","baseSeverity":"MEDIUM","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","integrityImpact":"NONE","userInteraction":"NONE","attackComplexity":"LOW","availabilityImpact":"HIGH","privilegesRequired":"LOW","confidentialityImpact":"NONE"}},{"other":{"type":"ssvc","content":{"id":"CVE-2025-21852","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2025-10-01T19:26:08.323491Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-476","lang":"en","type":"CWE","description":"CWE-476 NULL Pointer Dereference"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2025-10-01T19:26:38.622Z"}}]}}}