{"id":"CVE-2026-74563","aliases":[],"url":"https://o3.security/vulnerability/CVE-2026-74563","summary":"rds: tcp: hold the RCU lock across ipv6_chk_addr() in rds_tcp_laddr_check()","details":"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)","published":"2026-08-15T12:28:05.768Z","modified":"2026-08-18T03:56:51.771312124Z","cvss":{"score":7.8,"severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[{"ecosystem":"Linux","name":"Kernel","fixedVersion":"6.6.151"}],"fix":null,"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/76dd48886eeeb5fcf2b837d2f4c3d17eebeac9ef"},{"type":"WEB","url":"https://git.kernel.org/stable/c/78f75d632f74b8de0f081a128588f7c37d0d1164"},{"type":"WEB","url":"https://git.kernel.org/stable/c/8398bc477d3cb3e2b018a5aaac2bec0f69acda30"},{"type":"WEB","url":"https://git.kernel.org/stable/c/b1d480fce05f857dc438080cd8c9244b84a83494"},{"type":"WEB","url":"https://git.kernel.org/stable/c/f0d1fb05d70c8a561cd8d0473bcacafa2fc137ff"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74563.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-74563"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-18T03:56:51.771312124Z"}}