{"id":"CVE-2026-97566","state":"PUBLISHED","title":"mptcp: pm: kernel: drop pending ADD_ADDR when removing ID0","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nmptcp: pm: kernel: drop pending ADD_ADDR when removing ID0\n\nThe in-kernel MPTCP path manager can leave a stale ADD_ADDR announcement\nentry alive when removing the id 0 endpoint. This happens because the id 0\nremoval path does not tear down pending announcements, unlike the non-zero\nid path.\n\nWhen the PM later reselects id 0 after adding another signal endpoint, it\nfinds the stale anno_list entry and hits WARN_ON_ONCE(mptcp_pm_is_kernel())\nin mptcp_pm_announced_alloc().\n\nRoot cause: asymmetry between removal paths.\n- Non-zero id path: mptcp_nl_remove_subflow_and_signal_addr() calls\n  mptcp_pm_remove_announced() to clean up.\n- Id 0 path: mptcp_nl_remove_id_zero_address() skips cleanup entirely.\n\nFix by making the id 0 path symmetric: call mptcp_pm_announced_remove()\nand decrement add_addr_signaled before queuing the RM_ADDR.\n\nSubtle detail: signal endpoints are stored in anno_list with port 0, but\nmsk_local carries the connection's local port. In other words, entries\nlinked to ID0 paths should have port == 0. A follow-up patch will ensure\nthat. mptcp_pm_announced_remove() uses use_port=true for comparison. So\nclear the port before the lookup.","publishedAt":"2026-09-25T10:21:53.068Z","updatedAt":"2026-10-30T12:37:27.459Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"740d798e8767d8a449902b1a1bbc70facfce19b5","status":"affected","lessThan":"4af59a98aead422a152d805a89586dbb65616fc8","versionType":"git"},{"version":"740d798e8767d8a449902b1a1bbc70facfce19b5","status":"affected","lessThan":"189d60057e5f3d6a62e3d71a3cc428c9150bc14f","versionType":"git"},{"version":"740d798e8767d8a449902b1a1bbc70facfce19b5","status":"affected","lessThan":"bacf23e7c9876c9f4170166b3597cb22ea3ed39b","versionType":"git"},{"version":"740d798e8767d8a449902b1a1bbc70facfce19b5","status":"affected","lessThan":"d4a67a880654e1bfe318a31bea0bdbb026a09ade","versionType":"git"},{"version":"740d798e8767d8a449902b1a1bbc70facfce19b5","status":"affected","lessThan":"545616b4e7325be3c61fc082538cb06d14f7b1db","versionType":"git"},{"version":"740d798e8767d8a449902b1a1bbc70facfce19b5","status":"affected","lessThan":"2ac7d6e620764f1fc79eb4edd3610a7a661981ca","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/mptcp/pm_kernel.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.13","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.13","versionType":"semver"},{"version":"6.1.191","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.160","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.112","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.53","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.7","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/mptcp/pm_kernel.c"]}],"references":["https://git.kernel.org/stable/c/4af59a98aead422a152d805a89586dbb65616fc8","https://git.kernel.org/stable/c/189d60057e5f3d6a62e3d71a3cc428c9150bc14f","https://git.kernel.org/stable/c/bacf23e7c9876c9f4170166b3597cb22ea3ed39b","https://git.kernel.org/stable/c/d4a67a880654e1bfe318a31bea0bdbb026a09ade","https://git.kernel.org/stable/c/545616b4e7325be3c61fc082538cb06d14f7b1db","https://git.kernel.org/stable/c/2ac7d6e620764f1fc79eb4edd3610a7a661981ca"],"weaknesses":[],"ingestedAt":"2026-10-30T12:56:04.490Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/97xxx/CVE-2026-97566.json","commit":"1f312381e38164a43607eebab851b151dd16861e","baselineCommit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-97566","state":"PUBLISHED","datePublished":"2026-09-25T10:21:53.068Z","dateUpdated":"2026-10-30T12:37:27.459Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-24T16:01:01.155Z"},"containers":{"cna":{"title":"mptcp: pm: kernel: drop pending ADD_ADDR when removing ID0","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nmptcp: pm: kernel: drop pending ADD_ADDR when removing ID0\n\nThe in-kernel MPTCP path manager can leave a stale ADD_ADDR announcement\nentry alive when removing the id 0 endpoint. This happens because the id 0\nremoval path does not tear down pending announcements, unlike the non-zero\nid path.\n\nWhen the PM later reselects id 0 after adding another signal endpoint, it\nfinds the stale anno_list entry and hits WARN_ON_ONCE(mptcp_pm_is_kernel())\nin mptcp_pm_announced_alloc().\n\nRoot cause: asymmetry between removal paths.\n- Non-zero id path: mptcp_nl_remove_subflow_and_signal_addr() calls\n  mptcp_pm_remove_announced() to clean up.\n- Id 0 path: mptcp_nl_remove_id_zero_address() skips cleanup entirely.\n\nFix by making the id 0 path symmetric: call mptcp_pm_announced_remove()\nand decrement add_addr_signaled before queuing the RM_ADDR.\n\nSubtle detail: signal endpoints are stored in anno_list with port 0, but\nmsk_local carries the connection's local port. In other words, entries\nlinked to ID0 paths should have port == 0. A follow-up patch will ensure\nthat. mptcp_pm_announced_remove() uses use_port=true for comparison. So\nclear the port before the lookup."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"740d798e8767d8a449902b1a1bbc70facfce19b5","status":"affected","lessThan":"4af59a98aead422a152d805a89586dbb65616fc8","versionType":"git"},{"version":"740d798e8767d8a449902b1a1bbc70facfce19b5","status":"affected","lessThan":"189d60057e5f3d6a62e3d71a3cc428c9150bc14f","versionType":"git"},{"version":"740d798e8767d8a449902b1a1bbc70facfce19b5","status":"affected","lessThan":"bacf23e7c9876c9f4170166b3597cb22ea3ed39b","versionType":"git"},{"version":"740d798e8767d8a449902b1a1bbc70facfce19b5","status":"affected","lessThan":"d4a67a880654e1bfe318a31bea0bdbb026a09ade","versionType":"git"},{"version":"740d798e8767d8a449902b1a1bbc70facfce19b5","status":"affected","lessThan":"545616b4e7325be3c61fc082538cb06d14f7b1db","versionType":"git"},{"version":"740d798e8767d8a449902b1a1bbc70facfce19b5","status":"affected","lessThan":"2ac7d6e620764f1fc79eb4edd3610a7a661981ca","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/mptcp/pm_kernel.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.13","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.13","versionType":"semver"},{"version":"6.1.191","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.160","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.112","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.53","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.7","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/mptcp/pm_kernel.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/4af59a98aead422a152d805a89586dbb65616fc8"},{"url":"https://git.kernel.org/stable/c/189d60057e5f3d6a62e3d71a3cc428c9150bc14f"},{"url":"https://git.kernel.org/stable/c/bacf23e7c9876c9f4170166b3597cb22ea3ed39b"},{"url":"https://git.kernel.org/stable/c/d4a67a880654e1bfe318a31bea0bdbb026a09ade"},{"url":"https://git.kernel.org/stable/c/545616b4e7325be3c61fc082538cb06d14f7b1db"},{"url":"https://git.kernel.org/stable/c/2ac7d6e620764f1fc79eb4edd3610a7a661981ca"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-30T12:37:27.459Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.13","versionEndExcluding":"6.1.191"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.13","versionEndExcluding":"6.6.160"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.13","versionEndExcluding":"6.12.112"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.13","versionEndExcluding":"6.18.53"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.13","versionEndExcluding":"7.2.7"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.13","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}