{"id":"CVE-2026-74563","state":"PUBLISHED","title":"rds: tcp: hold the RCU lock across ipv6_chk_addr() in rds_tcp_laddr_check()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nrds: tcp: hold the RCU lock across ipv6_chk_addr() in rds_tcp_laddr_check()\n\nrds_tcp_laddr_check() looks up a scoped IPv6 interface with\ndev_get_by_index_rcu(), drops the RCU read-side lock, and only then\npasses the bare struct net_device * into ipv6_chk_addr().\n\ndev_get_by_index_rcu() only keeps the device alive within the same RCU\nread-side section. After rcu_read_unlock(), a concurrent RTM_DELLINK can\nfree the net_device; ipv6_chk_addr() then dereferences the stale pointer\nin __ipv6_chk_addr_and_flags() (e.g. l3mdev_master_dev_rcu(dev)), reading\nfreed memory.\n\nKeep the RCU read-side lock held across the ipv6_chk_addr() call instead\nof dropping it right after the lookup, so the device cannot be freed\nwhile it is in use.\n\n  BUG: KASAN: slab-use-after-free in __ipv6_chk_addr_and_flags (... net/ipv6/addrconf.c:1998)\n  Read of size 8 at addr ffff8880106ec000 by task exploit/153\n  Call Trace:\n   ...\n   kasan_report (mm/kasan/report.c:595)\n   __ipv6_chk_addr_and_flags (... net/ipv6/addrconf.c:1998)\n   ipv6_chk_addr (net/ipv6/addrconf.c:2031 net/ipv6/addrconf.c:1972)\n   rds_tcp_laddr_check (net/rds/tcp.c:370)\n   rds_bind (net/rds/bind.c:248)\n   __sys_bind (net/socket.c:1920)\n   __x64_sys_bind (net/socket.c:1956)\n   do_syscall_64 (arch/x86/entry/syscall_64.c:63)\n   entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121)","publishedAt":"2026-08-15T12:28:05.768Z","updatedAt":"2026-10-16T19:05:55.886Z","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":"eee2fa6ab3225192d6d894c54a6fb02ac9efdff6","status":"affected","lessThan":"f8a8977af2134a1d91e5f9773cb7d9d53278c830","versionType":"git"},{"version":"eee2fa6ab3225192d6d894c54a6fb02ac9efdff6","status":"affected","lessThan":"ba95bce5dfe6e2ef602a87e0557225f2934ccb5c","versionType":"git"},{"version":"eee2fa6ab3225192d6d894c54a6fb02ac9efdff6","status":"affected","lessThan":"c4933624a6f416ecfcc31ab58d585da1207a0597","versionType":"git"},{"version":"eee2fa6ab3225192d6d894c54a6fb02ac9efdff6","status":"affected","lessThan":"76dd48886eeeb5fcf2b837d2f4c3d17eebeac9ef","versionType":"git"},{"version":"eee2fa6ab3225192d6d894c54a6fb02ac9efdff6","status":"affected","lessThan":"f0d1fb05d70c8a561cd8d0473bcacafa2fc137ff","versionType":"git"},{"version":"eee2fa6ab3225192d6d894c54a6fb02ac9efdff6","status":"affected","lessThan":"b1d480fce05f857dc438080cd8c9244b84a83494","versionType":"git"},{"version":"eee2fa6ab3225192d6d894c54a6fb02ac9efdff6","status":"affected","lessThan":"8398bc477d3cb3e2b018a5aaac2bec0f69acda30","versionType":"git"},{"version":"eee2fa6ab3225192d6d894c54a6fb02ac9efdff6","status":"affected","lessThan":"78f75d632f74b8de0f081a128588f7c37d0d1164","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/rds/tcp.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.19","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.19","versionType":"semver"},{"version":"5.10.265","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.216","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.183","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.151","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.103","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.44","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.8","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/rds/tcp.c"]}],"references":["https://git.kernel.org/stable/c/f8a8977af2134a1d91e5f9773cb7d9d53278c830","https://git.kernel.org/stable/c/ba95bce5dfe6e2ef602a87e0557225f2934ccb5c","https://git.kernel.org/stable/c/c4933624a6f416ecfcc31ab58d585da1207a0597","https://git.kernel.org/stable/c/76dd48886eeeb5fcf2b837d2f4c3d17eebeac9ef","https://git.kernel.org/stable/c/f0d1fb05d70c8a561cd8d0473bcacafa2fc137ff","https://git.kernel.org/stable/c/b1d480fce05f857dc438080cd8c9244b84a83494","https://git.kernel.org/stable/c/8398bc477d3cb3e2b018a5aaac2bec0f69acda30","https://git.kernel.org/stable/c/78f75d632f74b8de0f081a128588f7c37d0d1164"],"weaknesses":[],"ingestedAt":"2026-10-29T20:12:58.252Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/74xxx/CVE-2026-74563.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-74563","state":"PUBLISHED","datePublished":"2026-08-15T12:28:05.768Z","dateUpdated":"2026-10-16T19:05:55.886Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-08-15T05:44:03.916Z"},"containers":{"cna":{"title":"rds: tcp: hold the RCU lock across ipv6_chk_addr() in rds_tcp_laddr_check()","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nrds: tcp: hold the RCU lock across ipv6_chk_addr() in rds_tcp_laddr_check()\n\nrds_tcp_laddr_check() looks up a scoped IPv6 interface with\ndev_get_by_index_rcu(), drops the RCU read-side lock, and only then\npasses the bare struct net_device * into ipv6_chk_addr().\n\ndev_get_by_index_rcu() only keeps the device alive within the same RCU\nread-side section. After rcu_read_unlock(), a concurrent RTM_DELLINK can\nfree the net_device; ipv6_chk_addr() then dereferences the stale pointer\nin __ipv6_chk_addr_and_flags() (e.g. l3mdev_master_dev_rcu(dev)), reading\nfreed memory.\n\nKeep the RCU read-side lock held across the ipv6_chk_addr() call instead\nof dropping it right after the lookup, so the device cannot be freed\nwhile it is in use.\n\n  BUG: KASAN: slab-use-after-free in __ipv6_chk_addr_and_flags (... net/ipv6/addrconf.c:1998)\n  Read of size 8 at addr ffff8880106ec000 by task exploit/153\n  Call Trace:\n   ...\n   kasan_report (mm/kasan/report.c:595)\n   __ipv6_chk_addr_and_flags (... net/ipv6/addrconf.c:1998)\n   ipv6_chk_addr (net/ipv6/addrconf.c:2031 net/ipv6/addrconf.c:1972)\n   rds_tcp_laddr_check (net/rds/tcp.c:370)\n   rds_bind (net/rds/bind.c:248)\n   __sys_bind (net/socket.c:1920)\n   __x64_sys_bind (net/socket.c:1956)\n   do_syscall_64 (arch/x86/entry/syscall_64.c:63)\n   entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121)"}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"eee2fa6ab3225192d6d894c54a6fb02ac9efdff6","status":"affected","lessThan":"f8a8977af2134a1d91e5f9773cb7d9d53278c830","versionType":"git"},{"version":"eee2fa6ab3225192d6d894c54a6fb02ac9efdff6","status":"affected","lessThan":"ba95bce5dfe6e2ef602a87e0557225f2934ccb5c","versionType":"git"},{"version":"eee2fa6ab3225192d6d894c54a6fb02ac9efdff6","status":"affected","lessThan":"c4933624a6f416ecfcc31ab58d585da1207a0597","versionType":"git"},{"version":"eee2fa6ab3225192d6d894c54a6fb02ac9efdff6","status":"affected","lessThan":"76dd48886eeeb5fcf2b837d2f4c3d17eebeac9ef","versionType":"git"},{"version":"eee2fa6ab3225192d6d894c54a6fb02ac9efdff6","status":"affected","lessThan":"f0d1fb05d70c8a561cd8d0473bcacafa2fc137ff","versionType":"git"},{"version":"eee2fa6ab3225192d6d894c54a6fb02ac9efdff6","status":"affected","lessThan":"b1d480fce05f857dc438080cd8c9244b84a83494","versionType":"git"},{"version":"eee2fa6ab3225192d6d894c54a6fb02ac9efdff6","status":"affected","lessThan":"8398bc477d3cb3e2b018a5aaac2bec0f69acda30","versionType":"git"},{"version":"eee2fa6ab3225192d6d894c54a6fb02ac9efdff6","status":"affected","lessThan":"78f75d632f74b8de0f081a128588f7c37d0d1164","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/rds/tcp.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.19","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.19","versionType":"semver"},{"version":"5.10.265","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.216","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.183","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.151","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.103","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.44","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.8","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/rds/tcp.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/f8a8977af2134a1d91e5f9773cb7d9d53278c830"},{"url":"https://git.kernel.org/stable/c/ba95bce5dfe6e2ef602a87e0557225f2934ccb5c"},{"url":"https://git.kernel.org/stable/c/c4933624a6f416ecfcc31ab58d585da1207a0597"},{"url":"https://git.kernel.org/stable/c/76dd48886eeeb5fcf2b837d2f4c3d17eebeac9ef"},{"url":"https://git.kernel.org/stable/c/f0d1fb05d70c8a561cd8d0473bcacafa2fc137ff"},{"url":"https://git.kernel.org/stable/c/b1d480fce05f857dc438080cd8c9244b84a83494"},{"url":"https://git.kernel.org/stable/c/8398bc477d3cb3e2b018a5aaac2bec0f69acda30"},{"url":"https://git.kernel.org/stable/c/78f75d632f74b8de0f081a128588f7c37d0d1164"}],"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 slab use-after-free is reached via the bind(2) syscall on an AF_RDS socket with a link-local IPv6 address and non-zero scope_id; the KASAN reproducer follows bind()->rds_bind()->rds_tcp_laddr_check(), requiring on-host access to race bind against RTM_DELLINK netlink deletion of the referenced netdev.\nAC:L - Exploitation requires racing rds_tcp_laddr_check() against RTM_DELLINK freeing the netdev; the attacker controls both sides by concurrently calling bind() and deleting the interface via netlink (e.g., a veth in a user namespace) and can retry until the race succeeds.\nPR:L - An unprivileged local user can create AF_RDS sockets and call bind(); the RTM_DELLINK race is achievable with CAP_NET_ADMIN obtainable inside an unprivileged user+network namespace (unshare -Urn), not requiring init-namespace root.\nUI:N - No victim interaction is required; exploitation is fully attacker-driven through bind/netlink syscalls without needing another user to mount a filesystem, click, or open a file.\nS:U - Impact is confined to kernel memory corruption and potential privilege escalation within the same kernel/host security boundary; this is not a VM-guest-to-host escape, sandbox escape, or cross-authority boundary crossing.\nC:H - The bug is a slab use-after-free read of a freed struct net_device in __ipv6_chk_addr_and_flags() via a stale pointer passed to ipv6_chk_addr(); UAF reads of kernel heap objects can disclose sensitive memory and enable further exploitation.\nI:H - Use-after-free on struct net_device heap memory provides memory corruption primitives that can be groomed for arbitrary kernel writes, control-flow hijacking, and local privilege escalation, not merely a bounded or transient error.\nA:H - The reported KASAN slab-use-after-free causes kernel oops/panic during the stale dereference in the IPv6 address-check path; UAF conditions are inherently crash-prone even when not fully weaponized for code execution."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-19T16:39:02.416Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.19","versionEndExcluding":"5.10.265"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.19","versionEndExcluding":"5.15.216"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.19","versionEndExcluding":"6.1.183"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.19","versionEndExcluding":"6.6.151"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.19","versionEndExcluding":"6.12.103"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.19","versionEndExcluding":"6.18.44"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.19","versionEndExcluding":"7.1.8"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.19","versionEndExcluding":"7.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-74563","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T19:00:11.789962Z"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-16T19:05:55.886Z"}}]}}}