{"id":"CVE-2024-26781","summary":"mptcp: fix possible deadlock in subflow diag","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nmptcp: fix possible deadlock in subflow diag\n\nSyzbot and Eric reported a lockdep splat in the subflow diag:\n\n   WARNING: possible circular locking dependency detected\n   6.8.0-rc4-syzkaller-00212-g40b9385dd8e6 #0 Not tainted\n\n   syz-executor.2/24141 is trying to acquire lock:\n   ffff888045870130 (k-sk_lock-AF_INET6){+.+.}-{0:0}, at:\n   tcp_diag_put_ulp net/ipv4/tcp_diag.c:100 [inline]\n   ffff888045870130 (k-sk_lock-AF_INET6){+.+.}-{0:0}, at:\n   tcp_diag_get_aux+0x738/0x830 net/ipv4/tcp_diag.c:137\n\n   but task is already holding lock:\n   ffffc9000135e488 (&h-\u003elhash2[i].lock){+.+.}-{2:2}, at: spin_lock\n   include/linux/spinlock.h:351 [inline]\n   ffffc9000135e488 (&h-\u003elhash2[i].lock){+.+.}-{2:2}, at:\n   inet_diag_dump_icsk+0x39f/0x1f80 net/ipv4/inet_diag.c:1038\n\n   which lock already depends on the new lock.\n\n   the existing dependency chain (in reverse order) is:\n\n   -\u003e #1 (&h-\u003elhash2[i].lock){+.+.}-{2:2}:\n   lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754\n   __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]\n   _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154\n   spin_lock include/linux/spinlock.h:351 [inline]\n   __inet_hash+0x335/0xbe0 net/ipv4/inet_hashtables.c:743\n   inet_csk_listen_start+0x23a/0x320 net/ipv4/inet_connection_sock.c:1261\n   __inet_listen_sk+0x2a2/0x770 net/ipv4/af_inet.c:217\n   inet_listen+0xa3/0x110 net/ipv4/af_inet.c:239\n   rds_tcp_listen_init+0x3fd/0x5a0 net/rds/tcp_listen.c:316\n   rds_tcp_init_net+0x141/0x320 net/rds/tcp.c:577\n   ops_init+0x352/0x610 net/core/net_namespace.c:136\n   __register_pernet_operations net/core/net_namespace.c:1214 [inline]\n   register_pernet_operations+0x2cb/0x660 net/core/net_namespace.c:1283\n   register_pernet_device+0x33/0x80 net/core/net_namespace.c:1370\n   rds_tcp_init+0x62/0xd0 net/rds/tcp.c:735\n   do_one_initcall+0x238/0x830 init/main.c:1236\n   do_initcall_level+0x157/0x210 init/main.c:1298\n   do_initcalls+0x3f/0x80 init/main.c:1314\n   kernel_init_freeable+0x42f/0x5d0 init/main.c:1551\n   kernel_init+0x1d/0x2a0 init/main.c:1441\n   ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147\n   ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:242\n\n   -\u003e #0 (k-sk_lock-AF_INET6){+.+.}-{0:0}:\n   check_prev_add kernel/locking/lockdep.c:3134 [inline]\n   check_prevs_add kernel/locking/lockdep.c:3253 [inline]\n   validate_chain+0x18ca/0x58e0 kernel/locking/lockdep.c:3869\n   __lock_acquire+0x1345/0x1fd0 kernel/locking/lockdep.c:5137\n   lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754\n   lock_sock_fast include/net/sock.h:1723 [inline]\n   subflow_get_info+0x166/0xd20 net/mptcp/diag.c:28\n   tcp_diag_put_ulp net/ipv4/tcp_diag.c:100 [inline]\n   tcp_diag_get_aux+0x738/0x830 net/ipv4/tcp_diag.c:137\n   inet_sk_diag_fill+0x10ed/0x1e00 net/ipv4/inet_diag.c:345\n   inet_diag_dump_icsk+0x55b/0x1f80 net/ipv4/inet_diag.c:1061\n   __inet_diag_dump+0x211/0x3a0 net/ipv4/inet_diag.c:1263\n   inet_diag_dump_compat+0x1c1/0x2d0 net/ipv4/inet_diag.c:1371\n   netlink_dump+0x59b/0xc80 net/netlink/af_netlink.c:2264\n   __netlink_dump_start+0x5df/0x790 net/netlink/af_netlink.c:2370\n   netlink_dump_start include/linux/netlink.h:338 [inline]\n   inet_diag_rcv_msg_compat+0x209/0x4c0 net/ipv4/inet_diag.c:1405\n   sock_diag_rcv_msg+0xe7/0x410\n   netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2543\n   sock_diag_rcv+0x2a/0x40 net/core/sock_diag.c:280\n   netlink_unicast_kernel net/netlink/af_netlink.c:1341 [inline]\n   netlink_unicast+0x7ea/0x980 net/netlink/af_netlink.c:1367\n   netlink_sendmsg+0xa3b/0xd70 net/netlink/af_netlink.c:1908\n   sock_sendmsg_nosec net/socket.c:730 [inline]\n   __sock_sendmsg+0x221/0x270 net/socket.c:745\n   ____sys_sendmsg+0x525/0x7d0 net/socket.c:2584\n   ___sys_sendmsg net/socket.c:2638 [inline]\n   __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2667\n   do_syscall_64+0xf9/0x240\n   entry_SYSCALL_64_after_hwframe+0x6f/0x77\n\nAs noted by Eric we can break the lock dependency chain avoid\ndumping \n---truncated---","modified":"2026-04-02T10:05:53.615255Z","published":"2024-04-04T08:20:15.775Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/26xxx/CVE-2024-26781.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/70e5b013538d5e4cb421afed431a5fcd2a5d49ee"},{"type":"WEB","url":"https://git.kernel.org/stable/c/cc32ba2fdf3f8b136619fff551f166ba51ec856d"},{"type":"WEB","url":"https://git.kernel.org/stable/c/d487e7ba1bc7444d5f062c4930ef8436c47c7e63"},{"type":"WEB","url":"https://git.kernel.org/stable/c/d6a9608af9a75d13243d217f6ce1e30e57d56ffe"},{"type":"WEB","url":"https://git.kernel.org/stable/c/f27d319df055629480b84b9288a502337b6f2a2e"},{"type":"WEB","url":"https://git.kernel.org/stable/c/fa8c776f4c323a9fbc8ddf25edcb962083391430"},{"type":"WEB","url":"https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/26xxx/CVE-2024-26781.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2024-26781"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"8affdbb3e2ef6b6a3a467b87dc336dc601dc2ed9"},{"fixed":"70e5b013538d5e4cb421afed431a5fcd2a5d49ee"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"7d6e8d7ee13b876e762b11f4ec210876ab7aec84"},{"fixed":"cc32ba2fdf3f8b136619fff551f166ba51ec856d"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"71787c665d09a970b9280c285181d3a2d1bf3bb0"},{"fixed":"f27d319df055629480b84b9288a502337b6f2a2e"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"e074c8297ee421e7ff352404262fe0e042954ab7"},{"fixed":"fa8c776f4c323a9fbc8ddf25edcb962083391430"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"298ac00da8e6bc2dcd690b45108acbd944c347d3"},{"fixed":"d487e7ba1bc7444d5f062c4930ef8436c47c7e63"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"b8adb69a7d29c2d33eb327bca66476fb6066516b"},{"fixed":"d6a9608af9a75d13243d217f6ce1e30e57d56ffe"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2024-26781.json"}}],"schema_version":"1.7.5"}