{"id":"CVE-2026-72383","state":"PUBLISHED","title":"sctp: fix addr_wq_timer race in sctp_free_addr_wq()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nsctp: fix addr_wq_timer race in sctp_free_addr_wq()\n\nsctp_free_addr_wq() previously removed addr_wq_timer using timer_delete()\nwhile holding addr_wq_lock. However, timer_delete() does not guarantee that\na currently running timer handler has completed.\n\nThis allows a race with sctp_addr_wq_timeout_handler(), where the handler\nmay still run after addr_waitq has been freed, acquire addr_wq_lock, and\naccess freed memory, leading to a use-after-free.\n\nFix this by calling timer_shutdown_sync() before taking addr_wq_lock.  This\nguarantees that any in-flight timer handler has finished and prevents the\ntimer from being re-armed during teardown, making subsequent cleanup safe.","publishedAt":"2026-08-15T05:56:14.755Z","updatedAt":"2026-10-30T12:29:14.606Z","severity":{"score":7.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/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":"4db67e808640e3934d82ce61ee8e2e89fd877ba8","status":"affected","lessThan":"fb6117713abef8646fdbf58256532451bcf26c47","versionType":"git"},{"version":"4db67e808640e3934d82ce61ee8e2e89fd877ba8","status":"affected","lessThan":"5098308ad72f83f3b1a48c247dddab1695114bae","versionType":"git"},{"version":"4db67e808640e3934d82ce61ee8e2e89fd877ba8","status":"affected","lessThan":"d49eff15261dd62e4fa3a316c26cb1f537a60464","versionType":"git"},{"version":"4db67e808640e3934d82ce61ee8e2e89fd877ba8","status":"affected","lessThan":"a8323fb2ab6cd6978f359daeed6688e0cadf32ba","versionType":"git"},{"version":"4db67e808640e3934d82ce61ee8e2e89fd877ba8","status":"affected","lessThan":"c3e5cac47519d77ad36b9c03a1df1536aaa0c4a1","versionType":"git"},{"version":"4db67e808640e3934d82ce61ee8e2e89fd877ba8","status":"affected","lessThan":"976c19de0f22a857ba0112f39635f8fd7a257568","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/sctp/protocol.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"3.7","status":"affected"},{"version":"0","status":"unaffected","lessThan":"3.7","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":"6.12.114","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.40","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.5","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/sctp/protocol.c"]}],"references":["https://git.kernel.org/stable/c/fb6117713abef8646fdbf58256532451bcf26c47","https://git.kernel.org/stable/c/5098308ad72f83f3b1a48c247dddab1695114bae","https://git.kernel.org/stable/c/d49eff15261dd62e4fa3a316c26cb1f537a60464","https://git.kernel.org/stable/c/a8323fb2ab6cd6978f359daeed6688e0cadf32ba","https://git.kernel.org/stable/c/c3e5cac47519d77ad36b9c03a1df1536aaa0c4a1","https://git.kernel.org/stable/c/976c19de0f22a857ba0112f39635f8fd7a257568"],"weaknesses":[],"ingestedAt":"2026-10-30T12:48:04.825Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/72xxx/CVE-2026-72383.json","commit":"1f312381e38164a43607eebab851b151dd16861e","baselineCommit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-72383","state":"PUBLISHED","datePublished":"2026-08-15T05:56:14.755Z","dateUpdated":"2026-10-30T12:29:14.606Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-08-09T03:40:39.923Z"},"containers":{"cna":{"title":"sctp: fix addr_wq_timer race in sctp_free_addr_wq()","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nsctp: fix addr_wq_timer race in sctp_free_addr_wq()\n\nsctp_free_addr_wq() previously removed addr_wq_timer using timer_delete()\nwhile holding addr_wq_lock. However, timer_delete() does not guarantee that\na currently running timer handler has completed.\n\nThis allows a race with sctp_addr_wq_timeout_handler(), where the handler\nmay still run after addr_waitq has been freed, acquire addr_wq_lock, and\naccess freed memory, leading to a use-after-free.\n\nFix this by calling timer_shutdown_sync() before taking addr_wq_lock.  This\nguarantees that any in-flight timer handler has finished and prevents the\ntimer from being re-armed during teardown, making subsequent cleanup safe."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"4db67e808640e3934d82ce61ee8e2e89fd877ba8","status":"affected","lessThan":"fb6117713abef8646fdbf58256532451bcf26c47","versionType":"git"},{"version":"4db67e808640e3934d82ce61ee8e2e89fd877ba8","status":"affected","lessThan":"5098308ad72f83f3b1a48c247dddab1695114bae","versionType":"git"},{"version":"4db67e808640e3934d82ce61ee8e2e89fd877ba8","status":"affected","lessThan":"d49eff15261dd62e4fa3a316c26cb1f537a60464","versionType":"git"},{"version":"4db67e808640e3934d82ce61ee8e2e89fd877ba8","status":"affected","lessThan":"a8323fb2ab6cd6978f359daeed6688e0cadf32ba","versionType":"git"},{"version":"4db67e808640e3934d82ce61ee8e2e89fd877ba8","status":"affected","lessThan":"c3e5cac47519d77ad36b9c03a1df1536aaa0c4a1","versionType":"git"},{"version":"4db67e808640e3934d82ce61ee8e2e89fd877ba8","status":"affected","lessThan":"976c19de0f22a857ba0112f39635f8fd7a257568","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/sctp/protocol.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"3.7","status":"affected"},{"version":"0","status":"unaffected","lessThan":"3.7","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":"6.12.114","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.40","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.5","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/sctp/protocol.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/fb6117713abef8646fdbf58256532451bcf26c47"},{"url":"https://git.kernel.org/stable/c/5098308ad72f83f3b1a48c247dddab1695114bae"},{"url":"https://git.kernel.org/stable/c/d49eff15261dd62e4fa3a316c26cb1f537a60464"},{"url":"https://git.kernel.org/stable/c/a8323fb2ab6cd6978f359daeed6688e0cadf32ba"},{"url":"https://git.kernel.org/stable/c/c3e5cac47519d77ad36b9c03a1df1536aaa0c4a1"},{"url":"https://git.kernel.org/stable/c/976c19de0f22a857ba0112f39635f8fd7a257568"}],"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 - The UAF is in sctp_free_addr_wq() during per-network-namespace SCTP teardown when a net namespace is destroyed; reaching it requires local syscalls (unshare/exit, SCTP socket/bind/setsockopt, rtnetlink address changes), not remote SCTP packet receive paths.\nAC:L - The attacker controls both sides of the race by creating a netns with SCTP AUTO_ASCONF sockets, queueing address events that arm addr_wq_timer (~500ms), and concurrently destroying that namespace; timer_delete() does not wait for sctp_addr_wq_timeout_handler(), so the UAF is reliably winnable.\nPR:L - An unprivileged local user can obtain CAP_NET_ADMIN in a new user+network namespace via unshare, bind an SCTP socket to INADDR_ANY, enable SCTP_AUTO_ASCONF, churn interface addresses to populate addr_waitq, and destroy the namespace; container tenants can trigger the same netns teardown without init-namespace root.\nUI:N - Exploitation is fully attacker-driven through scripted namespace create/configure/destroy and concurrent threads; no victim must mount filesystems, open files, or take any discretionary action beyond the attacker's own setup.\nS:U - The bug is kernel heap use-after-free of sctp_sockaddr_entry during netns teardown; impact is host kernel memory corruption and privilege escalation within the same kernel security authority, not a VM/hypervisor or IOMMU boundary crossing.\nC:H - sctp_addr_wq_timeout_handler() may walk addr_waitq and dereference sctp_sockaddr_entry fields after sctp_free_addr_wq() kfree()'s those entries; UAF on freed heap objects enables kernel memory disclosure and supports further exploitation primitives.\nI:H - The timer handler calls sctp_asconf_mgmt() on corrupted addrw pointers (address family, sockaddr, state), driving ASCONF add/delete processing on freed memory; UAF heap corruption is exploitable for arbitrary kernel write and potential code execution.\nA:H - Use-after-free in sctp_addr_wq_timeout_handler() during list iteration, socket locking, and sctp_asconf_mgmt() can cause kernel oops or panic from accesses to freed sctp_sockaddr_entry memory, even when full exploitation is not attempted."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-30T12:29:14.606Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.7","versionEndExcluding":"6.1.191"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.7","versionEndExcluding":"6.6.160"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.7","versionEndExcluding":"6.12.114"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.7","versionEndExcluding":"6.18.40"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.7","versionEndExcluding":"7.1.5"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.7","versionEndExcluding":"7.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-72383","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T18:48:17.297535Z"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-16T18:55:20.967Z"}}]}}}