============================================ WARNING: possible recursive locking detected 5.11.0-rc7-syzkaller #0 Not tainted -------------------------------------------- syz-executor.3/25843 is trying to acquire lock: ffff88802c658d60 (sk_lock-AF_INET6){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1598 [inline] ffff88802c658d60 (sk_lock-AF_INET6){+.+.}-{0:0}, at: mptcp_push_pending+0x28b/0x650 net/mptcp/protocol.c:1466 but task is already holding lock: ffff8880263ea520 (sk_lock-AF_INET6){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1598 [inline] ffff8880263ea520 (sk_lock-AF_INET6){+.+.}-{0:0}, at: sk_stream_wait_memory+0x87d/0xed0 net/core/stream.c:145 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(sk_lock-AF_INET6); lock(sk_lock-AF_INET6); *** DEADLOCK *** May be due to missing lock nesting notation 1 lock held by syz-executor.3/25843: #0: ffff8880263ea520 (sk_lock-AF_INET6){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1598 [inline] #0: ffff8880263ea520 (sk_lock-AF_INET6){+.+.}-{0:0}, at: sk_stream_wait_memory+0x87d/0xed0 net/core/stream.c:145 stack backtrace: CPU: 1 PID: 25843 Comm: syz-executor.3 Not tainted 5.11.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x107/0x163 lib/dump_stack.c:120 print_deadlock_bug kernel/locking/lockdep.c:2761 [inline] check_deadlock kernel/locking/lockdep.c:2804 [inline] validate_chain kernel/locking/lockdep.c:3595 [inline] __lock_acquire.cold+0x114/0x39e kernel/locking/lockdep.c:4832 lock_acquire kernel/locking/lockdep.c:5442 [inline] lock_acquire+0x1a8/0x720 kernel/locking/lockdep.c:5407 lock_sock_nested+0xc5/0x110 net/core/sock.c:3071 lock_sock include/net/sock.h:1598 [inline] mptcp_push_pending+0x28b/0x650 net/mptcp/protocol.c:1466 mptcp_sendmsg+0xde4/0x2830 net/mptcp/protocol.c:1685 inet6_sendmsg+0x99/0xe0 net/ipv6/af_inet6.c:638 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:672 sock_write_iter+0x289/0x3c0 net/socket.c:999 call_write_iter include/linux/fs.h:1901 [inline] new_sync_write+0x426/0x650 fs/read_write.c:518 vfs_write+0x791/0xa30 fs/read_write.c:605 ksys_write+0x1ee/0x250 fs/read_write.c:658 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x465d99 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:00007fc69d00f188 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 000000000056c0b0 RCX: 0000000000465d99 RDX: 0000000020000001 RSI: 0000000020000000 RDI: 0000000000000003 RBP: 00000000004bcf27 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c0b0 R13: 00007ffcaab34e9f R14: 00007fc69d00f300 R15: 0000000000022000 general protection fault, probably for non-canonical address 0xdffffc0000000007: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000038-0x000000000000003f] CPU: 1 PID: 25843 Comm: syz-executor.3 Not tainted 5.11.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:mptcp_sendmsg_frag+0xa3f/0x1220 net/mptcp/protocol.c:1330 Code: 80 3c 02 00 0f 85 04 07 00 00 48 8b 04 24 48 8b 98 20 07 00 00 48 b8 00 00 00 00 00 fc ff df 48 8d 7b 38 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 08 3c 03 0f 8e d6 04 00 00 48 8d 7d 10 44 8b RSP: 0018:ffffc9000190f7e8 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000007 RSI: 0000000000000000 RDI: 0000000000000038 RBP: ffff88805fbf9910 R08: 0000000000000001 R09: ffff88805fbf9910 R10: ffffed100bf7f324 R11: 0000000000000000 R12: ffff8880263ea400 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000204 FS: 00007fc69d00f700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055d35a801ae8 CR3: 0000000013865000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: mptcp_push_pending+0x2cc/0x650 net/mptcp/protocol.c:1477 mptcp_sendmsg+0xde4/0x2830 net/mptcp/protocol.c:1685 inet6_sendmsg+0x99/0xe0 net/ipv6/af_inet6.c:638 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:672 sock_write_iter+0x289/0x3c0 net/socket.c:999 call_write_iter include/linux/fs.h:1901 [inline] new_sync_write+0x426/0x650 fs/read_write.c:518 vfs_write+0x791/0xa30 fs/read_write.c:605 ksys_write+0x1ee/0x250 fs/read_write.c:658 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x465d99 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:00007fc69d00f188 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 000000000056c0b0 RCX: 0000000000465d99 RDX: 0000000020000001 RSI: 0000000020000000 RDI: 0000000000000003 RBP: 00000000004bcf27 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c0b0 R13: 00007ffcaab34e9f R14: 00007fc69d00f300 R15: 0000000000022000 Modules linked in: ---[ end trace 161d2db487bc27ff ]--- RIP: 0010:mptcp_sendmsg_frag+0xa3f/0x1220 net/mptcp/protocol.c:1330 Code: 80 3c 02 00 0f 85 04 07 00 00 48 8b 04 24 48 8b 98 20 07 00 00 48 b8 00 00 00 00 00 fc ff df 48 8d 7b 38 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 08 3c 03 0f 8e d6 04 00 00 48 8d 7d 10 44 8b RSP: 0018:ffffc9000190f7e8 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000007 RSI: 0000000000000000 RDI: 0000000000000038 RBP: ffff88805fbf9910 R08: 0000000000000001 R09: ffff88805fbf9910 R10: ffffed100bf7f324 R11: 0000000000000000 R12: ffff8880263ea400 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000204 FS: 00007fc69d00f700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000018c2708 CR3: 0000000013865000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400