bisecting fixing commit since 4707d8e5727387e36ea99c74d5ff0ad227700fd0 building syzkaller on e6b89e4e5adde15c0dc0a241e03dc215f2e249b3 testing commit 4707d8e5727387e36ea99c74d5ff0ad227700fd0 with gcc (GCC) 8.4.1 20210217 kernel signature: bdf3e754798f814668f34877d8b509fcc52858b113d4e0c231fd73755c58cd35 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_write run #8: crashed: INFO: task hung in pipe_write run #9: crashed: INFO: task hung in pipe_write run #10: crashed: INFO: task hung in pipe_write run #11: crashed: INFO: task hung in vfs_unlink run #12: crashed: INFO: task hung in pipe_write run #13: crashed: INFO: task hung in pipe_write run #14: crashed: INFO: task hung in pipe_write run #15: crashed: INFO: task hung in pipe_write run #16: crashed: INFO: task hung in pipe_write run #17: OK run #18: OK run #19: OK testing current HEAD 78fec1611cbf7b0bdaddfdbf174a3a2463663bff testing commit 78fec1611cbf7b0bdaddfdbf174a3a2463663bff with gcc (GCC) 8.4.1 20210217 kernel signature: 453614181d2b7ab878dc3fa0f0d395a73ba7b6232c700ee9cccc9e5313abf720 run #0: crashed: INFO: task hung in pipe_read 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_read run #6: crashed: INFO: task hung in pipe_write run #7: OK run #8: OK run #9: OK revisions tested: 2, total time: 33m14.429349749s (build: 15m34.09024019s, test: 17m10.185061815s) the crash still happens on HEAD commit msg: Linux 4.19.183 crash: INFO: task hung in pipe_write INFO: task syz-executor.5:8833 blocked for more than 140 seconds. Not tainted 4.19.183-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D29160 8833 5880 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: 0033:0x464319 Code: Bad RIP value. RSP: 002b:00007ff694328198 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000464319 RDX: 000000000208e24b RSI: 0000000020000040 RDI: 0000000000000000 RBP: 0000000000526220 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000055bf00 R13: 00007ff6943286bc R14: 00000000ffffffff R15: 0000000000000003 INFO: task syz-executor.5:10814 blocked for more than 140 seconds. Not tainted 4.19.183-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D29784 10814 5880 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: 0033:0x464319 Code: Bad RIP value. RSP: 002b:00007ff694328198 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000464319 RDX: 000000000208e24b RSI: 0000000020000040 RDI: 0000000000000000 RBP: 0000000000526220 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000055bf00 R13: 00007ff6943286bc R14: 00000000ffffffff R15: 0000000000000003 INFO: task syz-executor.5:10957 blocked for more than 140 seconds. Not tainted 4.19.183-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D29784 10957 5880 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: 0033:0x464319 Code: Bad RIP value. RSP: 002b:00007ff694328198 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000464319 RDX: 000000000208e24b RSI: 0000000020000040 RDI: 0000000000000000 RBP: 0000000000526220 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000055bf00 R13: 00007ff6943286bc R14: 00000000ffffffff R15: 0000000000000003 INFO: task syz-executor.0:10968 blocked for more than 140 seconds. Not tainted 4.19.183-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D28552 10968 5872 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: 0033:0x464319 Code: Bad RIP value. RSP: 002b:00007f799f51e198 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000464319 RDX: 000000000208e24b RSI: 0000000020000040 RDI: 0000000000000000 RBP: 0000000000526220 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000055bf00 R13: 00007f799f51e6bc R14: 00000000ffffffff R15: 0000000000000003 INFO: task syz-executor.5:11591 blocked for more than 140 seconds. Not tainted 4.19.183-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D29160 11591 5880 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: 0033:0x464319 Code: Bad RIP value. RSP: 002b:00007ff694328198 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000464319 RDX: 000000000208e24b RSI: 0000000020000040 RDI: 0000000000000000 RBP: 0000000000526220 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000055bf00 R13: 00007ff6943286bc R14: 00000000ffffffff R15: 0000000000000003 INFO: task syz-executor.5:11657 blocked for more than 140 seconds. Not tainted 4.19.183-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D29784 11657 5880 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: 0033:0x464319 Code: Bad RIP value. RSP: 002b:00007ff694328198 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000464319 RDX: 000000000208e24b RSI: 0000000020000040 RDI: 0000000000000000 RBP: 0000000000526220 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000055bf00 R13: 00007ff6943286bc R14: 00000000ffffffff R15: 0000000000000003 INFO: task syz-executor.5:12302 blocked for more than 140 seconds. Not tainted 4.19.183-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D29160 12302 5880 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: 0033:0x464319 Code: Bad RIP value. RSP: 002b:00007ff694328198 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000464319 RDX: 000000000208e24b RSI: 0000000020000040 RDI: 0000000000000000 RBP: 0000000000526220 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000055bf00 R13: 00007ff6943286bc R14: 00000000ffffffff R15: 0000000000000003 Showing all locks held in the system: 1 lock held by khungtaskd/1063: #0: 000000001db8a8c0 (rcu_read_lock){....}, at: debug_show_all_locks+0x5b/0x27a kernel/locking/lockdep.c:4442 1 lock held by in:imklog/5539: #0: 00000000b900ec2a (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xa7/0xd0 fs/file.c:767 1 lock held by syz-execprog/5858: #0: 00000000204ace8e (&pipe->mutex/1){+.+.}, at: pipe_lock_nested fs/pipe.c:62 [inline] #0: 00000000204ace8e (&pipe->mutex/1){+.+.}, at: pipe_lock fs/pipe.c:70 [inline] #0: 00000000204ace8e (&pipe->mutex/1){+.+.}, at: pipe_wait+0x185/0x1b0 fs/pipe.c:118 1 lock held by syz-executor.5/8739: #0: 00000000f3286155 (&pipe->mutex/1){+.+.}, at: pipe_lock_nested fs/pipe.c:62 [inline] #0: 00000000f3286155 (&pipe->mutex/1){+.+.}, at: pipe_lock fs/pipe.c:70 [inline] #0: 00000000f3286155 (&pipe->mutex/1){+.+.}, at: pipe_wait+0x185/0x1b0 fs/pipe.c:118 1 lock held by syz-executor.5/8833: #0: 00000000f3286155 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 00000000f3286155 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.0/8947: #0: 00000000204ace8e (&pipe->mutex/1){+.+.}, at: pipe_lock_nested fs/pipe.c:62 [inline] #0: 00000000204ace8e (&pipe->mutex/1){+.+.}, at: pipe_lock fs/pipe.c:70 [inline] #0: 00000000204ace8e (&pipe->mutex/1){+.+.}, at: pipe_wait+0x185/0x1b0 fs/pipe.c:118 1 lock held by syz-executor.5/10814: #0: 00000000f3286155 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 00000000f3286155 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.5/10957: #0: 00000000f3286155 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 00000000f3286155 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.0/10968: #0: 00000000204ace8e (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 00000000204ace8e (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.5/11591: #0: 00000000f3286155 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 00000000f3286155 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.5/11657: #0: 00000000f3286155 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 00000000f3286155 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.5/12302: #0: 00000000f3286155 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 00000000f3286155 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.4/14180: #0: 0000000077e52f43 (&pipe->mutex/1){+.+.}, at: pipe_lock_nested fs/pipe.c:62 [inline] #0: 0000000077e52f43 (&pipe->mutex/1){+.+.}, at: pipe_lock fs/pipe.c:70 [inline] #0: 0000000077e52f43 (&pipe->mutex/1){+.+.}, at: pipe_wait+0x185/0x1b0 fs/pipe.c:118 1 lock held by syz-executor.0/14376: #0: 00000000204ace8e (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 00000000204ace8e (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.1/14691: #0: 000000004c43ff73 (&pipe->mutex/1){+.+.}, at: pipe_lock_nested fs/pipe.c:62 [inline] #0: 000000004c43ff73 (&pipe->mutex/1){+.+.}, at: pipe_lock fs/pipe.c:70 [inline] #0: 000000004c43ff73 (&pipe->mutex/1){+.+.}, at: pipe_wait+0x185/0x1b0 fs/pipe.c:118 1 lock held by syz-executor.0/14724: #0: 00000000204ace8e (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 00000000204ace8e (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.4/14982: #0: 0000000077e52f43 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 0000000077e52f43 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.0/15155: #0: 00000000204ace8e (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 00000000204ace8e (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.5/15302: #0: 00000000f3286155 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 00000000f3286155 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.4/15344: #0: 0000000077e52f43 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 0000000077e52f43 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.0/15976: #0: 00000000204ace8e (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 00000000204ace8e (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.5/15995: #0: 00000000f3286155 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 00000000f3286155 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.3/16073: #0: 00000000ee88c0d6 (&pipe->mutex/1){+.+.}, at: pipe_lock_nested fs/pipe.c:62 [inline] #0: 00000000ee88c0d6 (&pipe->mutex/1){+.+.}, at: pipe_lock fs/pipe.c:70 [inline] #0: 00000000ee88c0d6 (&pipe->mutex/1){+.+.}, at: pipe_wait+0x185/0x1b0 fs/pipe.c:118 1 lock held by syz-executor.3/16173: #0: 00000000ee88c0d6 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 00000000ee88c0d6 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.3/16229: #0: 00000000ee88c0d6 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 00000000ee88c0d6 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.3/16393: #0: 00000000ee88c0d6 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 00000000ee88c0d6 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.3/16485: #0: 00000000ee88c0d6 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 00000000ee88c0d6 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.0/16573: #0: 00000000204ace8e (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 00000000204ace8e (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.5/16687: #0: 00000000f3286155 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 00000000f3286155 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.1/16913: #0: 000000004c43ff73 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 000000004c43ff73 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.3/16965: #0: 00000000ee88c0d6 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 00000000ee88c0d6 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.4/17118: #0: 0000000077e52f43 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 0000000077e52f43 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.4/17300: #0: 0000000077e52f43 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 0000000077e52f43 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.3/17661: #0: 00000000ee88c0d6 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 00000000ee88c0d6 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.4/17741: #0: 0000000077e52f43 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 0000000077e52f43 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.4/17783: #0: 0000000077e52f43 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 0000000077e52f43 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.0/17828: #0: 00000000204ace8e (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 00000000204ace8e (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.1/18079: #0: 000000004c43ff73 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 000000004c43ff73 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.1/18159: #0: 000000004c43ff73 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 000000004c43ff73 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.5/18162: #0: 00000000f3286155 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 00000000f3286155 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.0/18191: #0: 00000000204ace8e (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 00000000204ace8e (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.4/18245: #0: 0000000077e52f43 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 0000000077e52f43 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.3/18349: #0: 00000000ee88c0d6 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 00000000ee88c0d6 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.4/18350: #0: 0000000077e52f43 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 0000000077e52f43 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.0/18463: #0: 00000000204ace8e (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 00000000204ace8e (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.5/18737: #0: 00000000f3286155 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 00000000f3286155 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.0/18745: #0: 00000000204ace8e (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 00000000204ace8e (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.3/19164: #0: 00000000ee88c0d6 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 00000000ee88c0d6 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.3/19298: #0: 00000000ee88c0d6 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 00000000ee88c0d6 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.0/19386: #0: 00000000204ace8e (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 00000000204ace8e (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.0/19825: #0: 00000000204ace8e (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 00000000204ace8e (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.4/19873: #0: 0000000077e52f43 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 0000000077e52f43 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.5/19902: #0: 00000000f3286155 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 00000000f3286155 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.3/19914: #0: 00000000ee88c0d6 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 00000000ee88c0d6 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.1/19929: #0: 000000004c43ff73 (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 000000004c43ff73 (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.2/19999: #0: 000000003240cecd (&pipe->mutex/1){+.+.}, at: pipe_lock_nested fs/pipe.c:62 [inline] #0: 000000003240cecd (&pipe->mutex/1){+.+.}, at: pipe_lock fs/pipe.c:70 [inline] #0: 000000003240cecd (&pipe->mutex/1){+.+.}, at: pipe_wait+0x185/0x1b0 fs/pipe.c:118 1 lock held by syz-executor.2/20087: #0: 000000003240cecd (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 000000003240cecd (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 1 lock held by syz-executor.0/20047: #0: 00000000204ace8e (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 00000000204ace8e (&pipe->mutex/1){+.+.}, at: pipe_write+0xa6/0xd00 fs/pipe.c:380 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1063 Comm: khungtaskd Not tainted 4.19.183-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+0x17c/0x226 lib/dump_stack.c:118 nmi_cpu_backtrace.cold.0+0x3c/0x78 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0xf5/0x120 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: NMI backtrace for cpu 0 CPU: 0 PID: 10 Comm: rcu_preempt Not tainted 4.19.183-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:166 [inline] RIP: 0010:_raw_spin_unlock_irq+0x1/0x90 kernel/locking/spinlock.c:192 Code: ff ff ff e8 21 12 b7 fa eb a5 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 55 48 89 e5 0f 0b 66 2e 0f 1f 84 00 00 00 00 00 55 01 00 00 00 48 89 e5 53 48 89 fb 48 83 c7 18 48 8b 55 08 e8 f6 RSP: 0018:ffff8881f56dfad8 EFLAGS: 00000086 RAX: dffffc0000000000 RBX: ffff8881f56c6280 RCX: 1ffff1103ead8d65 RDX: 1ffffffff10a3f71 RSI: 0000000000000000 RDI: ffff8881f682c400 RBP: ffff8881f56dfb30 R08: 00000000000049f1 R09: ffffffff89c8d808 R10: ffff8881f56c6b08 R11: 0000000000000001 R12: ffff8881f682c400 R13: ffff8881f4446100 R14: ffff8881e3c90d40 R15: ffff8881f56c6280 FS: 0000000000000000(0000) GS:ffff8881f6800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007feed081c000 CR3: 000000000846d003 CR4: 00000000001606f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: context_switch kernel/sched/core.c:2831 [inline] __schedule+0x814/0x1f70 kernel/sched/core.c:3517 schedule+0x7f/0x1b0 kernel/sched/core.c:3561 schedule_timeout+0x398/0xd20 kernel/time/timer.c:1818 rcu_gp_kthread+0xd2b/0x23e0 kernel/rcu/tree.c:2202 kthread+0x347/0x410 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415