Hello, syzbot found the following issue on: HEAD commit: 9539ba4308ad Merge tag 'riscv-for-linus-5.16-rc2' of git:/.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=17f79d01b00000 kernel config: https://syzkaller.appspot.com/x/.config?x=6d3b8fd1977c1e73 dashboard link: https://syzkaller.appspot.com/bug?extid=e979d3597f48262cb4ee compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 Unfortunately, I don't have any reproducer for this issue yet. IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+e979d3597f48262cb4ee@xxxxxxxxxxxxxxxxxxxxxxxxx ============================================ WARNING: possible recursive locking detected 5.16.0-rc1-syzkaller #0 Not tainted -------------------------------------------- syz-executor.3/1337 is trying to acquire lock: ffff88809466ce58 (&ei->socket.wq.wait){..-.}-{2:2}, at: spin_lock include/linux/spinlock.h:349 [inline] ffff88809466ce58 (&ei->socket.wq.wait){..-.}-{2:2}, at: smc_switch_to_fallback+0x3d5/0x8c0 net/smc/af_smc.c:588 but task is already holding lock: ffff88809466c258 (&ei->socket.wq.wait){..-.}-{2:2}, at: smc_switch_to_fallback+0x3ca/0x8c0 net/smc/af_smc.c:587 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&ei->socket.wq.wait); lock(&ei->socket.wq.wait); *** DEADLOCK *** May be due to missing lock nesting notation 2 locks held by syz-executor.3/1337: #0: ffff888082ba8120 (sk_lock-AF_SMC){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1645 [inline] ffff888082ba8120 (sk_lock-AF_SMC){+.+.}-{0:0}, at: smc_setsockopt+0x2b7/0xa40 net/smc/af_smc.c:2449 #1: ffff88809466c258 (&ei->socket.wq.wait){..-.}-{2:2}, at: smc_switch_to_fallback+0x3ca/0x8c0 net/smc/af_smc.c:587 stack backtrace: CPU: 1 PID: 1337 Comm: syz-executor.3 Not tainted 5.16.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_deadlock_bug kernel/locking/lockdep.c:2956 [inline] check_deadlock kernel/locking/lockdep.c:2999 [inline] validate_chain kernel/locking/lockdep.c:3788 [inline] __lock_acquire.cold+0x149/0x3ab kernel/locking/lockdep.c:5027 lock_acquire kernel/locking/lockdep.c:5637 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5602 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:349 [inline] smc_switch_to_fallback+0x3d5/0x8c0 net/smc/af_smc.c:588 smc_setsockopt+0x8ee/0xa40 net/smc/af_smc.c:2459 __sys_setsockopt+0x2db/0x610 net/socket.c:2176 __do_sys_setsockopt net/socket.c:2187 [inline] __se_sys_setsockopt net/socket.c:2184 [inline] __x64_sys_setsockopt+0xba/0x150 net/socket.c:2184 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fa2a8fceae9 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 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fa2a6544188 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 00007fa2a90e1f60 RCX: 00007fa2a8fceae9 RDX: 0000000000000021 RSI: 0000000000000006 RDI: 0000000000000005 RBP: 00007fa2a9028f6d R08: 0000000000000010 R09: 0000000000000000 R10: 0000000020000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc2297067f R14: 00007fa2a6544300 R15: 0000000000022000 </TASK> --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot.