====================================================== WARNING: possible circular locking dependency detected 6.11.0-rc6-syzkaller-00355-g5dadc1be8fc5 #0 Not tainted ------------------------------------------------------ syz.2.2809/12885 is trying to acquire lock: ffff88802a274258 (sk_lock-AF_INET6){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1607 [inline] ffff88802a274258 (sk_lock-AF_INET6){+.+.}-{0:0}, at: sockopt_lock_sock net/core/sock.c:1061 [inline] ffff88802a274258 (sk_lock-AF_INET6){+.+.}-{0:0}, at: sockopt_lock_sock+0x54/0x70 net/core/sock.c:1052 but task is already holding lock: ffffffff8fa35b28 (rtnl_mutex){+.+.}-{3:3}, at: do_ipv6_setsockopt+0x214f/0x4790 net/ipv6/ipv6_sockglue.c:566 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (rtnl_mutex){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:608 [inline] __mutex_lock+0x175/0x9c0 kernel/locking/mutex.c:752 start_sync_thread+0x134/0x28e0 net/netfilter/ipvs/ip_vs_sync.c:1761 do_ip_vs_set_ctl+0x452/0x11c0 net/netfilter/ipvs/ip_vs_ctl.c:2732 nf_setsockopt+0x8a/0xf0 net/netfilter/nf_sockopt.c:101 ip_setsockopt+0xcb/0xf0 net/ipv4/ip_sockglue.c:1424 tcp_setsockopt+0xa4/0x100 net/ipv4/tcp.c:3768 smc_setsockopt+0x1b4/0xa00 net/smc/af_smc.c:3072 do_sock_setsockopt+0x222/0x480 net/socket.c:2324 __sys_setsockopt+0x1a4/0x270 net/socket.c:2347 __do_sys_setsockopt net/socket.c:2356 [inline] __se_sys_setsockopt net/socket.c:2353 [inline] __x64_sys_setsockopt+0xbd/0x160 net/socket.c:2353 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (&smc->clcsock_release_lock){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:608 [inline] __mutex_lock+0x175/0x9c0 kernel/locking/mutex.c:752 smc_switch_to_fallback+0x2d/0xa00 net/smc/af_smc.c:902 smc_sendmsg+0x13d/0x520 net/smc/af_smc.c:2779 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] __sys_sendto+0x47f/0x4e0 net/socket.c:2204 __do_sys_sendto net/socket.c:2216 [inline] __se_sys_sendto net/socket.c:2212 [inline] __x64_sys_sendto+0xe0/0x1c0 net/socket.c:2212 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (sk_lock-AF_INET6){+.+.}-{0:0}: check_prev_add kernel/locking/lockdep.c:3133 [inline] check_prevs_add kernel/locking/lockdep.c:3252 [inline] validate_chain kernel/locking/lockdep.c:3868 [inline] __lock_acquire+0x24ed/0x3cb0 kernel/locking/lockdep.c:5142 lock_acquire kernel/locking/lockdep.c:5759 [inline] lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5724 lock_sock_nested+0x3a/0xf0 net/core/sock.c:3543 lock_sock include/net/sock.h:1607 [inline] sockopt_lock_sock net/core/sock.c:1061 [inline] sockopt_lock_sock+0x54/0x70 net/core/sock.c:1052 do_ipv6_setsockopt+0x2157/0x4790 net/ipv6/ipv6_sockglue.c:567 ipv6_setsockopt+0xe3/0x1a0 net/ipv6/ipv6_sockglue.c:993 udpv6_setsockopt+0x7d/0xd0 net/ipv6/udp.c:1702 do_sock_setsockopt+0x222/0x480 net/socket.c:2324 __sys_setsockopt+0x1a4/0x270 net/socket.c:2347 __do_sys_setsockopt net/socket.c:2356 [inline] __se_sys_setsockopt net/socket.c:2353 [inline] __x64_sys_setsockopt+0xbd/0x160 net/socket.c:2353 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Chain exists of: sk_lock-AF_INET6 --> &smc->clcsock_release_lock --> rtnl_mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(rtnl_mutex); lock(&smc->clcsock_release_lock); lock(rtnl_mutex); lock(sk_lock-AF_INET6); *** DEADLOCK *** 1 lock held by syz.2.2809/12885: #0: ffffffff8fa35b28 (rtnl_mutex){+.+.}-{3:3}, at: do_ipv6_setsockopt+0x214f/0x4790 net/ipv6/ipv6_sockglue.c:566 stack backtrace: CPU: 3 UID: 0 PID: 12885 Comm: syz.2.2809 Not tainted 6.11.0-rc6-syzkaller-00355-g5dadc1be8fc5 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:93 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:119 check_noncircular+0x31a/0x400 kernel/locking/lockdep.c:2186 check_prev_add kernel/locking/lockdep.c:3133 [inline] check_prevs_add kernel/locking/lockdep.c:3252 [inline] validate_chain kernel/locking/lockdep.c:3868 [inline] __lock_acquire+0x24ed/0x3cb0 kernel/locking/lockdep.c:5142 lock_acquire kernel/locking/lockdep.c:5759 [inline] lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5724 lock_sock_nested+0x3a/0xf0 net/core/sock.c:3543 lock_sock include/net/sock.h:1607 [inline] sockopt_lock_sock net/core/sock.c:1061 [inline] sockopt_lock_sock+0x54/0x70 net/core/sock.c:1052 do_ipv6_setsockopt+0x2157/0x4790 net/ipv6/ipv6_sockglue.c:567 ipv6_setsockopt+0xe3/0x1a0 net/ipv6/ipv6_sockglue.c:993 udpv6_setsockopt+0x7d/0xd0 net/ipv6/udp.c:1702 do_sock_setsockopt+0x222/0x480 net/socket.c:2324 __sys_setsockopt+0x1a4/0x270 net/socket.c:2347 __do_sys_setsockopt net/socket.c:2356 [inline] __se_sys_setsockopt net/socket.c:2353 [inline] __x64_sys_setsockopt+0xbd/0x160 net/socket.c:2353 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f3d2377cef9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f3d231ff038 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 00007f3d23936130 RCX: 00007f3d2377cef9 RDX: 000000000000001b RSI: 0000000000000029 RDI: 0000000000000005 RBP: 00007f3d237ef046 R08: 0000000000000014 R09: 0000000000000000 R10: 0000000020000100 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f3d23936130 R15: 00007ffe18398cb8