{"id":"CVE-2025-38461","state":"PUBLISHED","title":"vsock: Fix transport_* TOCTOU","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nvsock: Fix transport_* TOCTOU\n\nTransport assignment may race with module unload. Protect new_transport\nfrom becoming a stale pointer.\n\nThis also takes care of an insecure call in vsock_use_local_transport();\nadd a lockdep assert.\n\nBUG: unable to handle page fault for address: fffffbfff8056000\nOops: Oops: 0000 [#1] SMP KASAN\nRIP: 0010:vsock_assign_transport+0x366/0x600\nCall Trace:\n vsock_connect+0x59c/0xc40\n __sys_connect+0xe8/0x100\n __x64_sys_connect+0x6e/0xc0\n do_syscall_64+0x92/0x1c0\n entry_SYSCALL_64_after_hwframe+0x4b/0x53","publishedAt":"2025-07-25T15:27:39.322Z","updatedAt":"2026-08-05T12:02:04.689Z","severity":{"score":7,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"c0cfa2d8a788fcf45df5bf4070ab2474c88d543a","status":"affected","lessThan":"8667e8d0eb46bc54fdae30ba2f4786407d3d88eb","versionType":"git"},{"version":"c0cfa2d8a788fcf45df5bf4070ab2474c88d543a","status":"affected","lessThan":"36a439049b34cca0b3661276049b84a1f76cc21a","versionType":"git"},{"version":"c0cfa2d8a788fcf45df5bf4070ab2474c88d543a","status":"affected","lessThan":"9ce53e744f18e73059d3124070e960f3aa9902bf","versionType":"git"},{"version":"c0cfa2d8a788fcf45df5bf4070ab2474c88d543a","status":"affected","lessThan":"9d24bb6780282b0255b9929abe5e8f98007e2c6e","versionType":"git"},{"version":"c0cfa2d8a788fcf45df5bf4070ab2474c88d543a","status":"affected","lessThan":"ae2c712ba39c7007de63cb0c75b51ce1caaf1da5","versionType":"git"},{"version":"c0cfa2d8a788fcf45df5bf4070ab2474c88d543a","status":"affected","lessThan":"7b73bddf54777fb62d4d8c7729d0affe6df04477","versionType":"git"},{"version":"c0cfa2d8a788fcf45df5bf4070ab2474c88d543a","status":"affected","lessThan":"687aa0c5581b8d4aa87fd92973e4ee576b550cdf","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/vmw_vsock/af_vsock.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.5","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.5","versionType":"semver"},{"version":"5.10.240","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.189","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.146","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.99","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.39","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.15.7","status":"unaffected","lessThanOrEqual":"6.15.*","versionType":"semver"},{"version":"6.16","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/vmw_vsock/af_vsock.c"]}],"references":["https://git.kernel.org/stable/c/8667e8d0eb46bc54fdae30ba2f4786407d3d88eb","https://git.kernel.org/stable/c/36a439049b34cca0b3661276049b84a1f76cc21a","https://git.kernel.org/stable/c/9ce53e744f18e73059d3124070e960f3aa9902bf","https://git.kernel.org/stable/c/9d24bb6780282b0255b9929abe5e8f98007e2c6e","https://git.kernel.org/stable/c/ae2c712ba39c7007de63cb0c75b51ce1caaf1da5","https://git.kernel.org/stable/c/7b73bddf54777fb62d4d8c7729d0affe6df04477","https://git.kernel.org/stable/c/687aa0c5581b8d4aa87fd92973e4ee576b550cdf","https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html","https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html"],"weaknesses":[],"ingestedAt":"2026-10-29T20:09:09.358Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2025/38xxx/CVE-2025-38461.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2025-38461","state":"PUBLISHED","datePublished":"2025-07-25T15:27:39.322Z","dateUpdated":"2026-08-05T12:02:04.689Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2025-04-16T04:51:24.020Z"},"containers":{"cna":{"title":"vsock: Fix transport_* TOCTOU","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nvsock: Fix transport_* TOCTOU\n\nTransport assignment may race with module unload. Protect new_transport\nfrom becoming a stale pointer.\n\nThis also takes care of an insecure call in vsock_use_local_transport();\nadd a lockdep assert.\n\nBUG: unable to handle page fault for address: fffffbfff8056000\nOops: Oops: 0000 [#1] SMP KASAN\nRIP: 0010:vsock_assign_transport+0x366/0x600\nCall Trace:\n vsock_connect+0x59c/0xc40\n __sys_connect+0xe8/0x100\n __x64_sys_connect+0x6e/0xc0\n do_syscall_64+0x92/0x1c0\n entry_SYSCALL_64_after_hwframe+0x4b/0x53"}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"c0cfa2d8a788fcf45df5bf4070ab2474c88d543a","status":"affected","lessThan":"8667e8d0eb46bc54fdae30ba2f4786407d3d88eb","versionType":"git"},{"version":"c0cfa2d8a788fcf45df5bf4070ab2474c88d543a","status":"affected","lessThan":"36a439049b34cca0b3661276049b84a1f76cc21a","versionType":"git"},{"version":"c0cfa2d8a788fcf45df5bf4070ab2474c88d543a","status":"affected","lessThan":"9ce53e744f18e73059d3124070e960f3aa9902bf","versionType":"git"},{"version":"c0cfa2d8a788fcf45df5bf4070ab2474c88d543a","status":"affected","lessThan":"9d24bb6780282b0255b9929abe5e8f98007e2c6e","versionType":"git"},{"version":"c0cfa2d8a788fcf45df5bf4070ab2474c88d543a","status":"affected","lessThan":"ae2c712ba39c7007de63cb0c75b51ce1caaf1da5","versionType":"git"},{"version":"c0cfa2d8a788fcf45df5bf4070ab2474c88d543a","status":"affected","lessThan":"7b73bddf54777fb62d4d8c7729d0affe6df04477","versionType":"git"},{"version":"c0cfa2d8a788fcf45df5bf4070ab2474c88d543a","status":"affected","lessThan":"687aa0c5581b8d4aa87fd92973e4ee576b550cdf","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/vmw_vsock/af_vsock.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.5","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.5","versionType":"semver"},{"version":"5.10.240","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.189","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.146","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.99","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.39","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.15.7","status":"unaffected","lessThanOrEqual":"6.15.*","versionType":"semver"},{"version":"6.16","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/vmw_vsock/af_vsock.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/8667e8d0eb46bc54fdae30ba2f4786407d3d88eb"},{"url":"https://git.kernel.org/stable/c/36a439049b34cca0b3661276049b84a1f76cc21a"},{"url":"https://git.kernel.org/stable/c/9ce53e744f18e73059d3124070e960f3aa9902bf"},{"url":"https://git.kernel.org/stable/c/9d24bb6780282b0255b9929abe5e8f98007e2c6e"},{"url":"https://git.kernel.org/stable/c/ae2c712ba39c7007de63cb0c75b51ce1caaf1da5"},{"url":"https://git.kernel.org/stable/c/7b73bddf54777fb62d4d8c7729d0affe6df04477"},{"url":"https://git.kernel.org/stable/c/687aa0c5581b8d4aa87fd92973e4ee576b550cdf"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The vulnerable code is reached through the AF_VSOCK socket API — `socket(AF_VSOCK, SOCK_DGRAM)` and `connect()` — which requires a local execution context on the target system. Per kernel scoring convention vsock is treated as a local attack vector even though the listener path is also driven by peer packets.\nAC:H - The attacker fully controls one side of the race (a tight `connect()`/`socket()` loop, and can widen the window via transport reassignment through `release()`/`destruct()`), but the other side requires a concurrent vsock transport module unload, which is gated by `capable(CAP_SYS_MODULE)` in the init user namespace and therefore cannot be induced by the attacker at will.\nPR:L - Creating an AF_VSOCK socket and calling connect() requires no capabilities whatsoever — there is no `capable()` gate on `vsock_create()` or `vsock_connect()` — so any unprivileged local user, including one inside an unprivileged container, can drive the racing side.\nUI:N - The attacker's exploitation path is pure syscall activity with no victim action required; the administrative module unload is a system-state precondition already accounted for in Attack Complexity and is not double-counted here.\nS:U - The stale-pointer dereference, wild write and indirect calls all occur in the host kernel's own security authority, which is the same authority that manages the vsock socket. This is standard kernel-level compromise with no crossing of a VM, IOMMU or sandbox boundary.\nC:H - This is a use-after-free on freed module memory: `new_transport->module` and the transport's function pointers are read from a region that has been released by `execmem_free()` and can be reallocated by a subsequent module load. Combined with the indirect calls through those stale pointers, this yields arbitrary kernel memory disclosure.\nI:H - `try_module_get()` performs `atomic_inc_not_zero()` on a `struct module *` read out of freed memory, giving an increment-write through an attacker-influenceable address, and `new_transport->seqpacket_allow()`/`->init()` are indirect calls through function pointers read from that same freed region — a control-flow hijack primitive.\nA:H - The bug is demonstrated by an unrecoverable oops — \"BUG: unable to handle page fault for address: fffffbfff8056000\" at `vsock_assign_transport+0x366` — and any use-after-free of this kind reliably panics the kernel even when not fully weaponized."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T12:02:04.689Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.5","versionEndExcluding":"5.10.240"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.5","versionEndExcluding":"5.15.189"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.5","versionEndExcluding":"6.1.146"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.5","versionEndExcluding":"6.6.99"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.5","versionEndExcluding":"6.12.39"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.5","versionEndExcluding":"6.15.7"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.5","versionEndExcluding":"6.16"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CVE Program Container","references":[{"url":"https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html"},{"url":"https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html"}],"providerMetadata":{"shortName":"CVE","orgId":"af854a3a-2127-422b-91ae-364da2661108","dateUpdated":"2025-11-03T17:38:21.774Z"}},{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2025-38461","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2026-06-10T20:41:43.452088Z"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-06-11T18:44:15.500Z"}}]}}}