bisecting fixing commit since 4707d8e5727387e36ea99c74d5ff0ad227700fd0 building syzkaller on e6b89e4e5adde15c0dc0a241e03dc215f2e249b3 testing commit 4707d8e5727387e36ea99c74d5ff0ad227700fd0 with gcc (GCC) 8.1.0 kernel signature: f740083d8dc34157ceaf96bc281404743814b19a4c51ef2d92c9299e3b5dd780 run #0: crashed: INFO: task hung in vfs_unlink run #1: crashed: INFO: task hung in vfs_unlink run #2: crashed: INFO: task hung in pipe_write run #3: crashed: INFO: task hung in pipe_write run #4: crashed: INFO: task hung in pipe_read run #5: crashed: INFO: task hung in pipe_write run #6: crashed: INFO: task hung in pipe_write run #7: crashed: INFO: task hung in pipe_write run #8: crashed: INFO: task hung in pipe_write run #9: crashed: INFO: task hung in pipe_read testing current HEAD c37da90efff5f183bea6ae4c2af33571f61fe317 testing commit c37da90efff5f183bea6ae4c2af33571f61fe317 with gcc (GCC) 8.1.0 kernel signature: c90c793d5fa8294b6ee0ae241937625b9c341d15802163aa5d966787b1ff29e6 run #0: crashed: INFO: task hung in pipe_write run #1: crashed: INFO: task hung in pipe_write run #2: crashed: INFO: task hung in pipe_write run #3: crashed: INFO: task hung in pipe_write run #4: crashed: INFO: task hung in pipe_write run #5: crashed: INFO: task hung in pipe_write run #6: crashed: INFO: task hung in pipe_write run #7: crashed: INFO: task hung in pipe_read run #8: OK run #9: OK revisions tested: 2, total time: 38m0.659979395s (build: 20m12.889848188s, test: 16m19.809572657s) the crash still happens on HEAD commit msg: Linux 4.19.143 crash: INFO: task hung in pipe_read bridge0: port 1(bridge_slave_0) entered disabled state device veth1_macvtap left promiscuous mode device veth0_macvtap left promiscuous mode device veth1_vlan left promiscuous mode device veth0_vlan left promiscuous mode INFO: task syz-execprog:6553 blocked for more than 140 seconds. Not tainted 4.19.143-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-execprog D24968 6553 6544 0x00000000 Call Trace: context_switch kernel/sched/core.c:2828 [inline] __schedule+0x80c/0x1f70 kernel/sched/core.c:3517 schedule+0x7f/0x1b0 kernel/sched/core.c:3561 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3619 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0x4c3/0x1200 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 __pipe_lock fs/pipe.c:83 [inline] pipe_read+0xaa/0x7b0 fs/pipe.c:274 call_read_iter include/linux/fs.h:1815 [inline] new_sync_read fs/read_write.c:406 [inline] __vfs_read+0x440/0x880 fs/read_write.c:418 vfs_read+0xf9/0x2f0 fs/read_write.c:452 ksys_read+0x103/0x260 fs/read_write.c:579 __do_sys_read fs/read_write.c:589 [inline] __se_sys_read fs/read_write.c:587 [inline] __x64_sys_read+0x6e/0xb0 fs/read_write.c:587 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4ad7db Code: Bad RIP value. RSP: 002b:000000c00002a610 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 000000c00001e000 RCX: 00000000004ad7db RDX: 0000000000010000 RSI: 000000c0001f6000 RDI: 000000000000001a RBP: 000000c00002a660 R08: 0000000000000001 R09: 0000000000000002 R10: 000000c0001e6000 R11: 0000000000000202 R12: 0000000000000003 R13: 000000c000000f00 R14: 0000000000000200 R15: 0000000000000000 INFO: task syz-executor.5:15005 blocked for more than 140 seconds. Not tainted 4.19.143-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D29784 15005 6580 0x00000000 Call Trace: context_switch kernel/sched/core.c:2828 [inline] __schedule+0x80c/0x1f70 kernel/sched/core.c:3517 schedule+0x7f/0x1b0 kernel/sched/core.c:3561 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3619 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0x4c3/0x1200 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 __pipe_lock fs/pipe.c:83 [inline] pipe_write+0xa6/0xd00 fs/pipe.c:380 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 vfs_write+0x150/0x4d0 fs/read_write.c:549 ksys_write+0x103/0x260 fs/read_write.c:599 __do_sys_write fs/read_write.c:611 [inline] __se_sys_write fs/read_write.c:608 [inline] __x64_sys_write+0x6e/0xb0 fs/read_write.c:608 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45cae9 Code: 8d b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 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 0f 83 5b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fe4bad06c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 000000000050ca00 RCX: 000000000045cae9 RDX: 000000000208e24b RSI: 0000000020000040 RDI: 0000000000000000 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000cec R14: 00000000004cf454 R15: 00007fe4bad076d4 Showing all locks held in the system: 3 locks held by kworker/0:0/5: #0: 00000000a6a58b69 ((wq_completion)"events"){+.+.}, at: process_one_work+0x6e8/0x15a0 kernel/workqueue.c:2126 #1: 00000000e3354806 (deferred_process_work){+.+.}, at: process_one_work+0x71b/0x15a0 kernel/workqueue.c:2130 #2: 00000000a556057f (rtnl_mutex){+.+.}, at: rtnl_lock+0x12/0x20 net/core/rtnetlink.c:77 5 locks held by kworker/u4:0/7: #0: 00000000e24bbf86 ((wq_completion)"%s""netns"){+.+.}, at: process_one_work+0x6e8/0x15a0 kernel/workqueue.c:2126 #1: 000000005ff7b36c (net_cleanup_work){+.+.}, at: process_one_work+0x71b/0x15a0 kernel/workqueue.c:2130 #2: 000000009786227b (pernet_ops_rwsem){++++}, at: cleanup_net+0xb4/0x850 net/core/net_namespace.c:520 #3: 00000000a556057f (rtnl_mutex){+.+.}, at: rtnl_lock+0x12/0x20 net/core/rtnetlink.c:77 #4: 000000008e5ad11d (rcu_preempt_state.exp_mutex){+.+.}, at: exp_funnel_lock kernel/rcu/tree_exp.h:297 [inline] #4: 000000008e5ad11d (rcu_preempt_state.exp_mutex){+.+.}, at: _synchronize_rcu_expedited+0x3a0/0x8a0 kernel/rcu/tree_exp.h:667 1 lock held by khungtaskd/1074: #0: 00000000f80879a2 (rcu_read_lock){....}, at: debug_show_all_locks+0x5b/0x27a kernel/locking/lockdep.c:4442 2 locks held by kworker/0:2/2806: #0: 00000000b292c9c9 ((wq_completion)"rcu_gp"){+.+.}, at: process_one_work+0x6e8/0x15a0 kernel/workqueue.c:2126 #1: 00000000c9c19cec ((work_completion)(&rew.rew_work)){+.+.}, at: process_one_work+0x71b/0x15a0 kernel/workqueue.c:2130 3 locks held by kworker/u4:6/4490: 1 lock held by syz-execprog/6553: #0: 000000004980ed21 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 000000004980ed21 (&pipe->mutex/1){+.+.}, at: pipe_read+0xaa/0x7b0 fs/pipe.c:274 1 lock held by syz-execprog/6568: #0: 000000008ee37249 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 000000008ee37249 (&pipe->mutex/1){+.+.}, at: pipe_read+0xaa/0x7b0 fs/pipe.c:274 3 locks held by kworker/0:3/6816: #0: 00000000a6a58b69 ((wq_completion)"events"){+.+.}, at: process_one_work+0x6e8/0x15a0 kernel/workqueue.c:2126 #1: 000000005f0567e4 ((linkwatch_work).work){+.+.}, at: process_one_work+0x71b/0x15a0 kernel/workqueue.c:2130 #2: 00000000a556057f (rtnl_mutex){+.+.}, at: rtnl_lock+0x12/0x20 net/core/rtnetlink.c:77 1 lock held by syz-executor.5/13478: #0: 0000000041eccac6 (&pipe->mutex/1){+.+.}, at: pipe_lock_nested fs/pipe.c:62 [inline] #0: 0000000041eccac6 (&pipe->mutex/1){+.+.}, at: pipe_lock fs/pipe.c:70 [inline] #0: 0000000041eccac6 (&pipe->mutex/1){+.+.}, at: pipe_wait+0x185/0x1b0 fs/pipe.c:118 1 lock held by syz-executor.3/14555: #0: 000000004980ed21 (&pipe->mutex/1){+.+.}, at: pipe_lock_nested fs/pipe.c:62 [inline] #0: 000000004980ed21 (&pipe->mutex/1){+.+.}, at: pipe_lock fs/pipe.c:70 [inline] #0: 000000004980ed21 (&pipe->mutex/1){+.+.}, at: pipe_wait+0x185/0x1b0 fs/pipe.c:118 1 lock held by syz-executor.5/15005: #0: 0000000041eccac6 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 0000000041eccac6 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.5/15621: #0: 0000000041eccac6 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 0000000041eccac6 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.5/15637: #0: 0000000041eccac6 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 0000000041eccac6 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.3/15803: #0: 000000004980ed21 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 000000004980ed21 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.1/16078: #0: 0000000041aafdd1 (&pipe->mutex/1){+.+.}, at: pipe_lock_nested fs/pipe.c:62 [inline] #0: 0000000041aafdd1 (&pipe->mutex/1){+.+.}, at: pipe_lock fs/pipe.c:70 [inline] #0: 0000000041aafdd1 (&pipe->mutex/1){+.+.}, at: pipe_wait+0x185/0x1b0 fs/pipe.c:118 1 lock held by syz-executor.1/16231: #0: 0000000041aafdd1 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 0000000041aafdd1 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.1/16697: #0: 0000000041aafdd1 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 0000000041aafdd1 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.1/16728: #0: 0000000041aafdd1 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 0000000041aafdd1 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.5/16764: #0: 0000000041eccac6 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 0000000041eccac6 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.5/16776: #0: 0000000041eccac6 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 0000000041eccac6 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.3/16821: #0: 000000004980ed21 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 000000004980ed21 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.1/16978: #0: 0000000041aafdd1 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 0000000041aafdd1 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.3/16994: #0: 000000004980ed21 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 000000004980ed21 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.5/17003: #0: 0000000041eccac6 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 0000000041eccac6 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.1/17054: #0: 0000000041aafdd1 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 0000000041aafdd1 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.5/17104: #0: 0000000041eccac6 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 0000000041eccac6 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.5/17120: #0: 0000000041eccac6 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 0000000041eccac6 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.3/17230: #0: 000000004980ed21 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 000000004980ed21 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.3/17243: #0: 000000004980ed21 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 000000004980ed21 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.5/17254: #0: 0000000041eccac6 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 0000000041eccac6 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.4/17401: #0: 000000008ee37249 (&pipe->mutex/1){+.+.}, at: pipe_lock_nested fs/pipe.c:62 [inline] #0: 000000008ee37249 (&pipe->mutex/1){+.+.}, at: pipe_lock fs/pipe.c:70 [inline] #0: 000000008ee37249 (&pipe->mutex/1){+.+.}, at: pipe_wait+0x185/0x1b0 fs/pipe.c:118 1 lock held by syz-executor.4/17426: #0: 000000008ee37249 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 000000008ee37249 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.4/17472: #0: 000000008ee37249 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 000000008ee37249 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.3/17487: #0: 000000004980ed21 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 000000004980ed21 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.4/17537: #0: 000000008ee37249 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 000000008ee37249 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.3/17544: #0: 000000004980ed21 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 000000004980ed21 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.5/17575: #0: 0000000041eccac6 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 0000000041eccac6 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.4/17611: #0: 000000008ee37249 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 000000008ee37249 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.5/17642: #0: 0000000041eccac6 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 0000000041eccac6 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.1/17643: #0: 0000000041aafdd1 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 0000000041aafdd1 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.3/17727: #0: 000000004980ed21 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 000000004980ed21 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.3/17775: #0: 000000004980ed21 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 000000004980ed21 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.1/17944: #0: 0000000041aafdd1 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 0000000041aafdd1 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.4/17948: #0: 000000008ee37249 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 000000008ee37249 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.1/18160: #0: 0000000041aafdd1 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 0000000041aafdd1 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.5/18175: #0: 0000000041eccac6 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 0000000041eccac6 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.3/18256: #0: 000000004980ed21 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 000000004980ed21 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.3/18309: #0: 000000004980ed21 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 000000004980ed21 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.4/18313: #0: 000000008ee37249 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 000000008ee37249 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.3/18326: #0: 000000004980ed21 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 000000004980ed21 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.0/18364: #0: 00000000a556057f (rtnl_mutex){+.+.}, at: rtnl_lock net/core/rtnetlink.c:77 [inline] #0: 00000000a556057f (rtnl_mutex){+.+.}, at: rtnetlink_rcv_msg+0x301/0x950 net/core/rtnetlink.c:4775 1 lock held by syz-executor.4/18375: #0: 000000008ee37249 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 000000008ee37249 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.3/18377: #0: 000000004980ed21 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 000000004980ed21 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.4/18426: #0: 000000008ee37249 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 000000008ee37249 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.3/18548: #0: 000000004980ed21 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 000000004980ed21 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.3/18561: #0: 000000004980ed21 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 000000004980ed21 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1074 Comm: khungtaskd Not tainted 4.19.143-syzkaller #0 device hsr_slave_1 left promiscuous mode 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+0x17c/0x22a lib/dump_stack.c:118 nmi_cpu_backtrace.cold.0+0x3c/0x78 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0xf5/0x119 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline] watchdog+0x5c3/0xb40 kernel/hung_task.c:287 kthread+0x347/0x410 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Sending NMI from CPU 1 to CPUs 0: device hsr_slave_0 left promiscuous mode NMI backtrace for cpu 0 CPU: 0 PID: 7 Comm: kworker/u4:0 Not tainted 4.19.143-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: netns cleanup_net RIP: 0010:format_decode+0x14/0x8c0 lib/vsprintf.c:2007 Code: 19 89 e8 cf 56 a7 fa 5d c3 0f 1f 00 66 2e 0f 1f 84 00 00 00 00 00 55 4c 8d 4e 07 48 b8 00 00 00 00 00 fc ff df 48 89 e5 41 57 <4c> 89 c9 41 56 48 c1 e9 03 49 89 f6 41 55 49 89 fd 41 54 4c 8d a5 RSP: 0018:ffff8880a9fd73f0 EFLAGS: 00000002 RAX: dffffc0000000000 RBX: ffffffff872a93ab RCX: 0000000000000039 RDX: 0000000000000003 RSI: ffff8880a9fd7470 RDI: ffffffff872a93ab RBP: ffff8880a9fd73f8 R08: dffffc0000000000 R09: ffff8880a9fd7477 R10: ffffffff872a93ab R11: ffffffff8a157626 R12: ffff8880a9fd74b0 R13: ffffffff8a15762d R14: ffff8880a9fd7470 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880aea00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe2696b9000 CR3: 00000000a89a8000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: vsnprintf+0x148/0x17a0 lib/vsprintf.c:2245 sprintf+0x9e/0xd0 lib/vsprintf.c:2495 print_time kernel/printk/printk.c:1264 [inline] print_prefix+0x218/0x370 kernel/printk/printk.c:1287 msg_print_text+0x92/0x170 kernel/printk/printk.c:1314 console_unlock+0x1fd/0xe20 kernel/printk/printk.c:2431 vprintk_emit+0x309/0x540 kernel/printk/printk.c:1965 vprintk_default+0x1a/0x20 kernel/printk/printk.c:2007 vprintk_func+0x49/0x12c kernel/printk/printk_safe.c:397 printk+0x9a/0xc0 kernel/printk/printk.c:2040 __dev_set_promiscuity.cold.72+0x3a/0x390 net/core/dev.c:7462 dev_set_promiscuity+0x48/0xc0 net/core/dev.c:7501 hsr_del_port+0x1be/0x2f0 net/hsr/hsr_slave.c:194 hsr_netdev_notify+0x572/0xa40 net/hsr/hsr_main.c:88 notifier_call_chain+0x8a/0x160 kernel/notifier.c:93 __raw_notifier_call_chain kernel/notifier.c:394 [inline] raw_notifier_call_chain+0x11/0x20 kernel/notifier.c:401 call_netdevice_notifiers_info+0x28/0x60 net/core/dev.c:1744 call_netdevice_notifiers net/core/dev.c:1762 [inline] rollback_registered_many+0x5a9/0xb50 net/core/dev.c:8187 unregister_netdevice_many+0x3e/0x1f0 net/core/dev.c:9310 default_device_exit_batch+0x2e4/0x3d0 net/core/dev.c:9781 ops_exit_list.isra.0+0xd3/0x120 net/core/net_namespace.c:156 cleanup_net+0x368/0x850 net/core/net_namespace.c:553 process_one_work+0x7b9/0x15a0 kernel/workqueue.c:2155 worker_thread+0x85/0xb60 kernel/workqueue.c:2298 kthread+0x347/0x410 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415