IPv6: ADDRCONF(NETDEV_UP): vxcan1: link is not ready 8021q: adding VLAN 0 to HW filter on device batadv0 IPv6: ADDRCONF(NETDEV_CHANGE): vxcan1: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vxcan0: link becomes ready ====================================================== WARNING: possible circular locking dependency detected 4.19.182-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor446/1571 is trying to acquire lock: 00000000e8f8cf0e (&pipe->mutex/1){+.+.}, at: pipe_lock_nested fs/pipe.c:62 [inline] 00000000e8f8cf0e (&pipe->mutex/1){+.+.}, at: pipe_lock+0x4f/0x60 fs/pipe.c:70 but task is already holding lock: 000000001692d276 (sb_writers#3){.+.+}, at: file_start_write include/linux/fs.h:2779 [inline] 000000001692d276 (sb_writers#3){.+.+}, at: do_splice+0xb4b/0x12b0 fs/splice.c:1153 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (sb_writers#3){.+.+}: percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:36 [inline] percpu_down_read include/linux/percpu-rwsem.h:59 [inline] __sb_start_write+0x55/0x220 fs/super.c:1366 file_start_write include/linux/fs.h:2779 [inline] ovl_write_iter+0x80f/0xb10 fs/overlayfs/file.c:282 call_write_iter include/linux/fs.h:1821 [inline] new_sync_write fs/read_write.c:474 [inline] __vfs_write+0x443/0x890 fs/read_write.c:487 __kernel_write+0xe4/0x350 fs/read_write.c:506 write_pipe_buf+0x154/0x1f0 fs/splice.c:798 splice_from_pipe_feed fs/splice.c:503 [inline] __splice_from_pipe+0x2cb/0x720 fs/splice.c:627 splice_from_pipe+0xbb/0x120 fs/splice.c:662 default_file_splice_write+0x18/0x50 fs/splice.c:810 do_splice_from fs/splice.c:852 [inline] do_splice+0xa25/0x12b0 fs/splice.c:1154 __do_sys_splice fs/splice.c:1428 [inline] __se_sys_splice fs/splice.c:1408 [inline] __x64_sys_splice+0x248/0x300 fs/splice.c:1408 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #1 (&ovl_i_mutex_key[depth]){+.+.}: down_write+0x38/0x90 kernel/locking/rwsem.c:70 inode_lock include/linux/fs.h:748 [inline] ovl_write_iter+0x12d/0xb10 fs/overlayfs/file.c:270 call_write_iter include/linux/fs.h:1821 [inline] new_sync_write fs/read_write.c:474 [inline] __vfs_write+0x443/0x890 fs/read_write.c:487 __kernel_write+0xe4/0x350 fs/read_write.c:506 write_pipe_buf+0x154/0x1f0 fs/splice.c:798 splice_from_pipe_feed fs/splice.c:503 [inline] __splice_from_pipe+0x2cb/0x720 fs/splice.c:627 splice_from_pipe+0xbb/0x120 fs/splice.c:662 default_file_splice_write+0x18/0x50 fs/splice.c:810 do_splice_from fs/splice.c:852 [inline] do_splice+0xa25/0x12b0 fs/splice.c:1154 __do_sys_splice fs/splice.c:1428 [inline] __se_sys_splice fs/splice.c:1408 [inline] __x64_sys_splice+0x248/0x300 fs/splice.c:1408 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #0 (&pipe->mutex/1){+.+.}: lock_acquire+0x173/0x3d0 kernel/locking/lockdep.c:3907 __mutex_lock_common kernel/locking/mutex.c:925 [inline] __mutex_lock+0xf5/0x1200 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 pipe_lock_nested fs/pipe.c:62 [inline] pipe_lock+0x4f/0x60 fs/pipe.c:70 iter_file_splice_write+0x144/0xc40 fs/splice.c:700 do_splice_from fs/splice.c:852 [inline] do_splice+0xa25/0x12b0 fs/splice.c:1154 __do_sys_splice fs/splice.c:1428 [inline] __se_sys_splice fs/splice.c:1408 [inline] __x64_sys_splice+0x248/0x300 fs/splice.c:1408 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe other info that might help us debug this: Chain exists of: &pipe->mutex/1 --> &ovl_i_mutex_key[depth] --> sb_writers#3 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(sb_writers#3); lock(&ovl_i_mutex_key[depth]); lock(sb_writers#3); lock(&pipe->mutex/1); *** DEADLOCK *** 1 lock held by syz-executor446/1571: #0: 000000001692d276 (sb_writers#3){.+.+}, at: file_start_write include/linux/fs.h:2779 [inline] #0: 000000001692d276 (sb_writers#3){.+.+}, at: do_splice+0xb4b/0x12b0 fs/splice.c:1153 stack backtrace: CPU: 0 PID: 1571 Comm: syz-executor446 Not tainted 4.19.182-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x123/0x171 lib/dump_stack.c:118 print_circular_bug.isra.34.cold.55+0x1bd/0x27d kernel/locking/lockdep.c:1221 check_prev_add kernel/locking/lockdep.c:1865 [inline] check_prevs_add kernel/locking/lockdep.c:1978 [inline] validate_chain kernel/locking/lockdep.c:2419 [inline] __lock_acquire+0x30bb/0x4950 kernel/locking/lockdep.c:3415 lock_acquire+0x173/0x3d0 kernel/locking/lockdep.c:3907 __mutex_lock_common kernel/locking/mutex.c:925 [inline] __mutex_lock+0xf5/0x1200 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 pipe_lock_nested fs/pipe.c:62 [inline] pipe_lock+0x4f/0x60 fs/pipe.c:70 iter_file_splice_write+0x144/0xc40 fs/splice.c:700 do_splice_from fs/splice.c:852 [inline] do_splice+0xa25/0x12b0 fs/splice.c:1154 __do_sys_splice fs/splice.c:1428 [inline] __se_sys_splice fs/splice.c:1408 [inline] __x64_sys_splice+0x248/0x300 fs/splice.c:1408 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4489e9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 01 16 00 00 90 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:00007f7f335181f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000113 RAX: ffffffffffffffda RBX: 00000000004cf4e8 RCX: 00000000004489e9 RDX: 0000000000000004 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00000000004cf4e0 R08: 0000000100000002 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004cf4ec R13: 00007ffc627306cf R14: 00007f7f33518300 R15: 0000000000022000