{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-99213","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-09-25T10:25:14.401Z","datePublished":"2026-10-28T10:36:06.441Z","dateUpdated":"2026-10-31T12:45:10.380Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-10-31T12:45:10.380Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nvsock: treat TCP_CLOSING as once-established\n\nHandle the TCP_ESTABLISHED -> TCP_CLOSING transition on OP_RST, which can\nrace with the connect loop. Immediately break and return 0 on\nESTABLISHED/CLOSING. The return value of connect() should reflect what\nhappened up to the point the connection was established or failed. Events\nthat occur afterwards must not affect it. E.g. even if OP_RW has already\nset sk_err, connect() should still return 0, not ENOBUFS because of it.\nAdapt the inaccurate comment above signal_pending().\n\nResetting a socket that is still present in connected_table can lead to\nmemory corruption. The reporter noted lost transports for in-flight skbs,\nand I have reproduced crashes caused by re-insertion into connected_table.\n\n  list_add double add: new=, prev=, next=.\n  kernel BUG at lib/list_debug.c:35!\n  Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI\n  Workqueue: vsock-loopback vsock_loopback_work\n  RIP: 0010:__list_add_valid_or_report+0x11f/0x130\n  Call Trace:\n   vsock_insert_connected.cold+0xe/0x13\n   virtio_transport_recv_pkt+0x10e9/0x1460\n   vsock_loopback_work+0x305/0x480\n   process_one_work+0xe4c/0x1560\n   worker_thread+0x4f1/0xd60\n   kthread+0x36e/0x470\n   ret_from_fork+0x47b/0x6b0\n   ret_from_fork_asm+0x1a/0x30\n\nThis fix is supplementary to commit 002541ef650b (\"vsock: Ignore\nsignal/timeout on connect() if already established\"). Details under Link."}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - A local connect() on AF_VSOCK reaches the patched vsock_connect() through connect_socket() and vsock_stream_ops.connect; VMADDR_CID_LOCAL drives the response and reset through vsock_loopback_work(), not a routable network protocol.\nAC:L - The same attacker can operate both VMADDR_CID_LOCAL endpoints, deliver signals while connect() races with RESPONSE/RST processing, and retry connect() until the controlled window is hit.\nPR:L - vsock_create() and vsock_connect() impose no capability check, and vsock_auto_bind() selects an unreserved port; CAP_NET_BIND_SERVICE is checked only for an explicit port at or below LAST_RESERVED_PORT.\nUI:N - The attacker's own threads perform socket creation, connect, peer reset, signal delivery, and reconnection without any action by another user.\nS:U - The corrupted connected_table and transport state belong to the same kernel reached by the local AF_VSOCK caller; this path does not cross a guest-host, IOMMU, or other security authority boundary.\nC:H - A transport-changing reconnect reaches vsock_deassign_transport() and virtio_transport_destruct(), freeing vsk->trans while virtio_transport_consume_skb_sent() can retain and dereference it for an in-flight skb; this heap use-after-free can expose reclaimed kernel contents.\nI:H - A same-transport reconnect passes the already-linked connected_table node to vsock_insert_connected() and list_add(), while the transport-change path can modify a freed virtio_vsock_sock through bytes_unsent; these corruptions support heap grooming and control-flow hijacking.\nA:H - The demonstrated re-insertion reaches __list_add_valid_or_report() and its list_add double-add BUG, producing a kernel Oops from vsock_loopback_work(); the attacker can repeat the connection sequence."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/vmw_vsock/af_vsock.c"],"versions":[{"version":"d021c344051af91f42c5ba9fdedc176740cbd238","lessThan":"ea36ef3c229d54b552432d1290aee1d807f67fd5","status":"affected","versionType":"git"},{"version":"d021c344051af91f42c5ba9fdedc176740cbd238","lessThan":"5f2ab77028602a22f0cc33cac063a313787cbeae","status":"affected","versionType":"git"},{"version":"d021c344051af91f42c5ba9fdedc176740cbd238","lessThan":"f89770c7365748d9d6a2ae07d1c23497ca21ec07","status":"affected","versionType":"git"},{"version":"d021c344051af91f42c5ba9fdedc176740cbd238","lessThan":"deb972c7eea8d0bc3109c35c30a1c86d4939f811","status":"affected","versionType":"git"},{"version":"d021c344051af91f42c5ba9fdedc176740cbd238","lessThan":"baf1b5715640e434249ce7f63f94bd1a00938ef9","status":"affected","versionType":"git"},{"version":"d021c344051af91f42c5ba9fdedc176740cbd238","lessThan":"c2c5359ef2c33684fa3f3652fd761a483db8d1e7","status":"affected","versionType":"git"},{"version":"d021c344051af91f42c5ba9fdedc176740cbd238","lessThan":"44d1ca05d6094a5d75c671a0545249186d790b8d","status":"affected","versionType":"git"},{"version":"d021c344051af91f42c5ba9fdedc176740cbd238","lessThan":"4f6ac74fa594a918d41255c941256e1d51592d3b","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/vmw_vsock/af_vsock.c"],"versions":[{"version":"3.9","status":"affected"},{"version":"0","lessThan":"3.9","status":"unaffected","versionType":"semver"},{"version":"5.10.273","lessThanOrEqual":"5.10.*","status":"unaffected","versionType":"semver"},{"version":"5.15.224","lessThanOrEqual":"5.15.*","status":"unaffected","versionType":"semver"},{"version":"6.1.191","lessThanOrEqual":"6.1.*","status":"unaffected","versionType":"semver"},{"version":"6.6.161","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.115","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.59","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.2.13","lessThanOrEqual":"7.2.*","status":"unaffected","versionType":"semver"},{"version":"7.3","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.9","versionEndExcluding":"5.10.273"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.9","versionEndExcluding":"5.15.224"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.9","versionEndExcluding":"6.1.191"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.9","versionEndExcluding":"6.6.161"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.9","versionEndExcluding":"6.12.115"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.9","versionEndExcluding":"6.18.59"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.9","versionEndExcluding":"7.2.13"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.9","versionEndExcluding":"7.3"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/ea36ef3c229d54b552432d1290aee1d807f67fd5"},{"url":"https://git.kernel.org/stable/c/5f2ab77028602a22f0cc33cac063a313787cbeae"},{"url":"https://git.kernel.org/stable/c/f89770c7365748d9d6a2ae07d1c23497ca21ec07"},{"url":"https://git.kernel.org/stable/c/deb972c7eea8d0bc3109c35c30a1c86d4939f811"},{"url":"https://git.kernel.org/stable/c/baf1b5715640e434249ce7f63f94bd1a00938ef9"},{"url":"https://git.kernel.org/stable/c/c2c5359ef2c33684fa3f3652fd761a483db8d1e7"},{"url":"https://git.kernel.org/stable/c/44d1ca05d6094a5d75c671a0545249186d790b8d"},{"url":"https://git.kernel.org/stable/c/4f6ac74fa594a918d41255c941256e1d51592d3b"}],"title":"vsock: treat TCP_CLOSING as once-established","x_generator":{"engine":"bippy-1.2.0"}}}}