{"id":"CVE-2026-74563","title":"rds: tcp: hold the RCU lock across ipv6_chk_addr() in rds_tcp_laddr_check()","summary":"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 t…","severity":"high","cvss":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cvssSource":"cna","vendor":"Linux","product":"Linux","affected":["Linux >= eee2fa6ab3225192d6d894c54a6fb02ac9efdff6 < f8a8977af2134a1d91e5f9773cb7d9d53278c830","Linux >= eee2fa6ab3225192d6d894c54a6fb02ac9efdff6 < ba95bce5dfe6e2ef602a87e0557225f2934ccb5c","Linux >= eee2fa6ab3225192d6d894c54a6fb02ac9efdff6 < c4933624a6f416ecfcc31ab58d585da1207a0597","Linux >= eee2fa6ab3225192d6d894c54a6fb02ac9efdff6 < 76dd48886eeeb5fcf2b837d2f4c3d17eebeac9ef","Linux >= eee2fa6ab3225192d6d894c54a6fb02ac9efdff6 < f0d1fb05d70c8a561cd8d0473bcacafa2fc137ff","Linux >= eee2fa6ab3225192d6d894c54a6fb02ac9efdff6 < b1d480fce05f857dc438080cd8c9244b84a83494","Linux >= eee2fa6ab3225192d6d894c54a6fb02ac9efdff6 < 8398bc477d3cb3e2b018a5aaac2bec0f69acda30","Linux >= eee2fa6ab3225192d6d894c54a6fb02ac9efdff6 < 78f75d632f74b8de0f081a128588f7c37d0d1164","Linux 4.19"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-10-16T19:00:11.789962Z"},"published":"2026-08-15","updated":"2026-10-16","sourceUpdated":"2026-10-16T19:05:55.886Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-74563","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"}],"tags":["cve.org"],"epss":0.00117,"epssPercentile":0.01569,"ingestedAt":"2026-10-16T19:46:24.343Z","slug":"CVE-2026-74563","body":"## Overview\n\nIn 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)\n\n## Affected\n\n- `Linux >= eee2fa6ab3225192d6d894c54a6fb02ac9efdff6 < f8a8977af2134a1d91e5f9773cb7d9d53278c830`\n- `Linux >= eee2fa6ab3225192d6d894c54a6fb02ac9efdff6 < ba95bce5dfe6e2ef602a87e0557225f2934ccb5c`\n- `Linux >= eee2fa6ab3225192d6d894c54a6fb02ac9efdff6 < c4933624a6f416ecfcc31ab58d585da1207a0597`\n- `Linux >= eee2fa6ab3225192d6d894c54a6fb02ac9efdff6 < 76dd48886eeeb5fcf2b837d2f4c3d17eebeac9ef`\n- `Linux >= eee2fa6ab3225192d6d894c54a6fb02ac9efdff6 < f0d1fb05d70c8a561cd8d0473bcacafa2fc137ff`\n- `Linux >= eee2fa6ab3225192d6d894c54a6fb02ac9efdff6 < b1d480fce05f857dc438080cd8c9244b84a83494`\n- `Linux >= eee2fa6ab3225192d6d894c54a6fb02ac9efdff6 < 8398bc477d3cb3e2b018a5aaac2bec0f69acda30`\n- `Linux >= eee2fa6ab3225192d6d894c54a6fb02ac9efdff6 < 78f75d632f74b8de0f081a128588f7c37d0d1164`\n- `Linux 4.19`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":43,"depthScoreParts":{"impact":42.9,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}