====================================================== WARNING: possible circular locking dependency detected 6.15.0-rc1-syzkaller-00301-g3bde70a2c827 #0 Not tainted ------------------------------------------------------ syz.0.825/10003 is trying to acquire lock: ffff88803507c5d8 (sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1651 [inline] ffff88803507c5d8 (sk_lock-AF_INET){+.+.}-{0:0}, at: sockopt_lock_sock net/core/sock.c:1148 [inline] ffff88803507c5d8 (sk_lock-AF_INET){+.+.}-{0:0}, at: sockopt_lock_sock+0x54/0x70 net/core/sock.c:1139 but task is already holding lock: ffffffff9012daa8 (rtnl_mutex){+.+.}-{4:4}, at: do_ip_getsockopt+0x1843/0x2220 net/ipv4/ip_sockglue.c:1702 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (rtnl_mutex){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:601 [inline] __mutex_lock+0x199/0xb90 kernel/locking/mutex.c:746 do_ipv6_setsockopt+0x2042/0x4420 net/ipv6/ipv6_sockglue.c:566 ipv6_setsockopt+0xcb/0x170 net/ipv6/ipv6_sockglue.c:993 tcp_setsockopt+0xa4/0x100 net/ipv4/tcp.c:4077 smc_setsockopt+0x1b3/0xa00 net/smc/af_smc.c:3081 do_sock_setsockopt+0x221/0x470 net/socket.c:2296 __sys_setsockopt+0x1a0/0x230 net/socket.c:2321 __do_sys_setsockopt net/socket.c:2327 [inline] __se_sys_setsockopt net/socket.c:2324 [inline] __x64_sys_setsockopt+0xbd/0x160 net/socket.c:2324 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (&smc->clcsock_release_lock){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:601 [inline] __mutex_lock+0x199/0xb90 kernel/locking/mutex.c:746 smc_switch_to_fallback+0x2d/0x9f0 net/smc/af_smc.c:903 smc_sendmsg+0x13d/0x520 net/smc/af_smc.c:2781 sock_sendmsg_nosec net/socket.c:712 [inline] __sock_sendmsg net/socket.c:727 [inline] ____sys_sendmsg+0xa95/0xc70 net/socket.c:2566 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2620 __sys_sendmsg+0x16d/0x220 net/socket.c:2652 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (sk_lock-AF_INET){+.+.}-{0:0}: check_prev_add kernel/locking/lockdep.c:3166 [inline] check_prevs_add kernel/locking/lockdep.c:3285 [inline] validate_chain kernel/locking/lockdep.c:3909 [inline] __lock_acquire+0x1173/0x1ba0 kernel/locking/lockdep.c:5235 lock_acquire kernel/locking/lockdep.c:5866 [inline] lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5823 lock_sock_nested+0x41/0xf0 net/core/sock.c:3702 lock_sock include/net/sock.h:1651 [inline] sockopt_lock_sock net/core/sock.c:1148 [inline] sockopt_lock_sock+0x54/0x70 net/core/sock.c:1139 do_ip_getsockopt+0x13e4/0x2220 net/ipv4/ip_sockglue.c:1703 ip_getsockopt+0x9b/0x1e0 net/ipv4/ip_sockglue.c:1765 raw_getsockopt+0x4d/0x1f0 net/ipv4/raw.c:865 do_sock_getsockopt+0x3fc/0x800 net/socket.c:2357 __sys_getsockopt+0x12f/0x260 net/socket.c:2386 __do_sys_getsockopt net/socket.c:2393 [inline] __se_sys_getsockopt net/socket.c:2390 [inline] __x64_sys_getsockopt+0xbd/0x160 net/socket.c:2390 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Chain exists of: sk_lock-AF_INET --> &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_INET); *** DEADLOCK *** 1 lock held by syz.0.825/10003: #0: ffffffff9012daa8 (rtnl_mutex){+.+.}-{4:4}, at: do_ip_getsockopt+0x1843/0x2220 net/ipv4/ip_sockglue.c:1702 stack backtrace: CPU: 1 UID: 0 PID: 10003 Comm: syz.0.825 Not tainted 6.15.0-rc1-syzkaller-00301-g3bde70a2c827 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_circular_bug+0x275/0x350 kernel/locking/lockdep.c:2079 check_noncircular+0x14c/0x170 kernel/locking/lockdep.c:2211 check_prev_add kernel/locking/lockdep.c:3166 [inline] check_prevs_add kernel/locking/lockdep.c:3285 [inline] validate_chain kernel/locking/lockdep.c:3909 [inline] __lock_acquire+0x1173/0x1ba0 kernel/locking/lockdep.c:5235 lock_acquire kernel/locking/lockdep.c:5866 [inline] lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5823 lock_sock_nested+0x41/0xf0 net/core/sock.c:3702 lock_sock include/net/sock.h:1651 [inline] sockopt_lock_sock net/core/sock.c:1148 [inline] sockopt_lock_sock+0x54/0x70 net/core/sock.c:1139 do_ip_getsockopt+0x13e4/0x2220 net/ipv4/ip_sockglue.c:1703 ip_getsockopt+0x9b/0x1e0 net/ipv4/ip_sockglue.c:1765 raw_getsockopt+0x4d/0x1f0 net/ipv4/raw.c:865 do_sock_getsockopt+0x3fc/0x800 net/socket.c:2357 __sys_getsockopt+0x12f/0x260 net/socket.c:2386 __do_sys_getsockopt net/socket.c:2393 [inline] __se_sys_getsockopt net/socket.c:2390 [inline] __x64_sys_getsockopt+0xbd/0x160 net/socket.c:2390 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f6fb7b8d169 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:00007f6fb8a0e038 EFLAGS: 00000246 ORIG_RAX: 0000000000000037 RAX: ffffffffffffffda RBX: 00007f6fb7da5fa0 RCX: 00007f6fb7b8d169 RDX: 0000000000000029 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f6fb7c0e990 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f6fb7da5fa0 R15: 00007fffdabfa808