====================================================== WARNING: possible circular locking dependency detected 4.14.218-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.3/1548 is trying to acquire lock: (&event->child_mutex){+.+.}, at: [] perf_read_group syzkaller/managers/linux-4-14/kernel/kernel/events/core.c:4542 [inline] (&event->child_mutex){+.+.}, at: [] __perf_read syzkaller/managers/linux-4-14/kernel/kernel/events/core.c:4624 [inline] (&event->child_mutex){+.+.}, at: [] perf_read+0x2a2/0x7c0 syzkaller/managers/linux-4-14/kernel/kernel/events/core.c:4639 but task is already holding lock: (&cpuctx_mutex){+.+.}, at: [] perf_event_ctx_lock_nested+0x14d/0x2c0 syzkaller/managers/linux-4-14/kernel/kernel/events/core.c:1241 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #5 (&cpuctx_mutex){+.+.}: __mutex_lock_common syzkaller/managers/linux-4-14/kernel/kernel/locking/mutex.c:756 [inline] __mutex_lock+0xc4/0x1310 syzkaller/managers/linux-4-14/kernel/kernel/locking/mutex.c:893 perf_event_init_cpu+0xb7/0x170 syzkaller/managers/linux-4-14/kernel/kernel/events/core.c:11250 perf_event_init+0x2cc/0x308 syzkaller/managers/linux-4-14/kernel/kernel/events/core.c:11297 start_kernel+0x46a/0x770 syzkaller/managers/linux-4-14/kernel/init/main.c:620 secondary_startup_64+0xa5/0xb0 syzkaller/managers/linux-4-14/kernel/arch/x86/kernel/head_64.S:240 -> #4 (pmus_lock){+.+.}: __mutex_lock_common syzkaller/managers/linux-4-14/kernel/kernel/locking/mutex.c:756 [inline] __mutex_lock+0xc4/0x1310 syzkaller/managers/linux-4-14/kernel/kernel/locking/mutex.c:893 perf_event_init_cpu+0x2c/0x170 syzkaller/managers/linux-4-14/kernel/kernel/events/core.c:11244 cpuhp_invoke_callback+0x1e6/0x1a80 syzkaller/managers/linux-4-14/kernel/kernel/cpu.c:184 cpuhp_up_callbacks syzkaller/managers/linux-4-14/kernel/kernel/cpu.c:572 [inline] _cpu_up+0x219/0x500 syzkaller/managers/linux-4-14/kernel/kernel/cpu.c:1144 do_cpu_up+0x9a/0x160 syzkaller/managers/linux-4-14/kernel/kernel/cpu.c:1179 smp_init+0x197/0x1ac syzkaller/managers/linux-4-14/kernel/kernel/smp.c:578 kernel_init_freeable+0x3f4/0x614 syzkaller/managers/linux-4-14/kernel/init/main.c:1068 kernel_init+0xd/0x162 syzkaller/managers/linux-4-14/kernel/init/main.c:1000 ret_from_fork+0x24/0x30 syzkaller/managers/linux-4-14/kernel/arch/x86/entry/entry_64.S:404 -> #3 (cpu_hotplug_lock.rw_sem){++++}: percpu_down_read_preempt_disable syzkaller/managers/linux-4-14/kernel/./include/linux/percpu-rwsem.h:36 [inline] percpu_down_read syzkaller/managers/linux-4-14/kernel/./include/linux/percpu-rwsem.h:59 [inline] cpus_read_lock+0x39/0xc0 syzkaller/managers/linux-4-14/kernel/kernel/cpu.c:295 static_key_slow_inc+0xe/0x20 syzkaller/managers/linux-4-14/kernel/kernel/jump_label.c:123 tracepoint_add_func+0x516/0x750 syzkaller/managers/linux-4-14/kernel/kernel/tracepoint.c:223 tracepoint_probe_register_prio syzkaller/managers/linux-4-14/kernel/kernel/tracepoint.c:283 [inline] tracepoint_probe_register+0x8c/0xc0 syzkaller/managers/linux-4-14/kernel/kernel/tracepoint.c:304 trace_event_reg+0x272/0x330 syzkaller/managers/linux-4-14/kernel/kernel/trace/trace_events.c:305 perf_trace_event_reg syzkaller/managers/linux-4-14/kernel/kernel/trace/trace_event_perf.c:122 [inline] perf_trace_event_init syzkaller/managers/linux-4-14/kernel/kernel/trace/trace_event_perf.c:197 [inline] perf_trace_init+0x424/0xa30 syzkaller/managers/linux-4-14/kernel/kernel/trace/trace_event_perf.c:221 perf_tp_event_init+0x79/0xf0 syzkaller/managers/linux-4-14/kernel/kernel/events/core.c:8138 perf_try_init_event+0x15b/0x1f0 syzkaller/managers/linux-4-14/kernel/kernel/events/core.c:9369 perf_init_event syzkaller/managers/linux-4-14/kernel/kernel/events/core.c:9407 [inline] perf_event_alloc.part.0+0xe2d/0x2640 syzkaller/managers/linux-4-14/kernel/kernel/events/core.c:9667 perf_event_alloc syzkaller/managers/linux-4-14/kernel/kernel/events/core.c:10020 [inline] SYSC_perf_event_open syzkaller/managers/linux-4-14/kernel/kernel/events/core.c:10124 [inline] SyS_perf_event_open+0x67f/0x24b0 syzkaller/managers/linux-4-14/kernel/kernel/events/core.c:10010 do_syscall_64+0x1d5/0x640 syzkaller/managers/linux-4-14/kernel/arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb -> #2 (tracepoints_mutex){+.+.}: __mutex_lock_common syzkaller/managers/linux-4-14/kernel/kernel/locking/mutex.c:756 [inline] __mutex_lock+0xc4/0x1310 syzkaller/managers/linux-4-14/kernel/kernel/locking/mutex.c:893 tracepoint_probe_register_prio syzkaller/managers/linux-4-14/kernel/kernel/tracepoint.c:279 [inline] tracepoint_probe_register+0x68/0xc0 syzkaller/managers/linux-4-14/kernel/kernel/tracepoint.c:304 trace_event_reg+0x272/0x330 syzkaller/managers/linux-4-14/kernel/kernel/trace/trace_events.c:305 perf_trace_event_reg syzkaller/managers/linux-4-14/kernel/kernel/trace/trace_event_perf.c:122 [inline] perf_trace_event_init syzkaller/managers/linux-4-14/kernel/kernel/trace/trace_event_perf.c:197 [inline] perf_trace_init+0x424/0xa30 syzkaller/managers/linux-4-14/kernel/kernel/trace/trace_event_perf.c:221 perf_tp_event_init+0x79/0xf0 syzkaller/managers/linux-4-14/kernel/kernel/events/core.c:8138 perf_try_init_event+0x15b/0x1f0 syzkaller/managers/linux-4-14/kernel/kernel/events/core.c:9369 perf_init_event syzkaller/managers/linux-4-14/kernel/kernel/events/core.c:9407 [inline] perf_event_alloc.part.0+0xe2d/0x2640 syzkaller/managers/linux-4-14/kernel/kernel/events/core.c:9667 perf_event_alloc syzkaller/managers/linux-4-14/kernel/kernel/events/core.c:10020 [inline] SYSC_perf_event_open syzkaller/managers/linux-4-14/kernel/kernel/events/core.c:10124 [inline] SyS_perf_event_open+0x67f/0x24b0 syzkaller/managers/linux-4-14/kernel/kernel/events/core.c:10010 do_syscall_64+0x1d5/0x640 syzkaller/managers/linux-4-14/kernel/arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb -> #1 (event_mutex){+.+.}: __mutex_lock_common syzkaller/managers/linux-4-14/kernel/kernel/locking/mutex.c:756 [inline] __mutex_lock+0xc4/0x1310 syzkaller/managers/linux-4-14/kernel/kernel/locking/mutex.c:893 perf_trace_destroy+0x23/0xf0 syzkaller/managers/linux-4-14/kernel/kernel/trace/trace_event_perf.c:234 _free_event+0x321/0xe20 syzkaller/managers/linux-4-14/kernel/kernel/events/core.c:4244 free_event+0x32/0x40 syzkaller/managers/linux-4-14/kernel/kernel/events/core.c:4271 perf_event_release_kernel+0x368/0x8a0 syzkaller/managers/linux-4-14/kernel/kernel/events/core.c:4415 perf_release+0x33/0x40 syzkaller/managers/linux-4-14/kernel/kernel/events/core.c:4441 __fput+0x25f/0x7a0 syzkaller/managers/linux-4-14/kernel/fs/file_table.c:210 task_work_run+0x11f/0x190 syzkaller/managers/linux-4-14/kernel/kernel/task_work.c:113 exit_task_work syzkaller/managers/linux-4-14/kernel/./include/linux/task_work.h:22 [inline] do_exit+0xa44/0x2850 syzkaller/managers/linux-4-14/kernel/kernel/exit.c:868 do_group_exit+0x100/0x2e0 syzkaller/managers/linux-4-14/kernel/kernel/exit.c:965 get_signal+0x38d/0x1ca0 syzkaller/managers/linux-4-14/kernel/kernel/signal.c:2423 do_signal+0x7c/0x1550 syzkaller/managers/linux-4-14/kernel/arch/x86/kernel/signal.c:814 exit_to_usermode_loop+0x160/0x200 syzkaller/managers/linux-4-14/kernel/arch/x86/entry/common.c:160 prepare_exit_to_usermode+0x1af/0x210 syzkaller/managers/linux-4-14/kernel/arch/x86/entry/common.c:199 retint_user+0x8/0x18 -> #0 (&event->child_mutex){+.+.}: lock_acquire+0x170/0x3f0 syzkaller/managers/linux-4-14/kernel/kernel/locking/lockdep.c:3998 __mutex_lock_common syzkaller/managers/linux-4-14/kernel/kernel/locking/mutex.c:756 [inline] __mutex_lock+0xc4/0x1310 syzkaller/managers/linux-4-14/kernel/kernel/locking/mutex.c:893 perf_read_group syzkaller/managers/linux-4-14/kernel/kernel/events/core.c:4542 [inline] __perf_read syzkaller/managers/linux-4-14/kernel/kernel/events/core.c:4624 [inline] perf_read+0x2a2/0x7c0 syzkaller/managers/linux-4-14/kernel/kernel/events/core.c:4639 __vfs_read+0xe4/0x620 syzkaller/managers/linux-4-14/kernel/fs/read_write.c:411 vfs_read+0x139/0x340 syzkaller/managers/linux-4-14/kernel/fs/read_write.c:447 SYSC_read syzkaller/managers/linux-4-14/kernel/fs/read_write.c:574 [inline] SyS_read+0xf2/0x210 syzkaller/managers/linux-4-14/kernel/fs/read_write.c:567 do_syscall_64+0x1d5/0x640 syzkaller/managers/linux-4-14/kernel/arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb other info that might help us debug this: Chain exists of: &event->child_mutex --> pmus_lock --> &cpuctx_mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&cpuctx_mutex); lock(pmus_lock); lock(&cpuctx_mutex); lock(&event->child_mutex); *** DEADLOCK *** 1 lock held by syz-executor.3/1548: #0: (&cpuctx_mutex){+.+.}, at: [] perf_event_ctx_lock_nested+0x14d/0x2c0 syzkaller/managers/linux-4-14/kernel/kernel/events/core.c:1241 stack backtrace: CPU: 1 PID: 1548 Comm: syz-executor.3 Not tainted 4.14.218-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack syzkaller/managers/linux-4-14/kernel/lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x281 syzkaller/managers/linux-4-14/kernel/lib/dump_stack.c:58 print_circular_bug.constprop.0.cold+0x2d7/0x41e syzkaller/managers/linux-4-14/kernel/kernel/locking/lockdep.c:1258 check_prev_add syzkaller/managers/linux-4-14/kernel/kernel/locking/lockdep.c:1905 [inline] check_prevs_add syzkaller/managers/linux-4-14/kernel/kernel/locking/lockdep.c:2022 [inline] validate_chain syzkaller/managers/linux-4-14/kernel/kernel/locking/lockdep.c:2464 [inline] __lock_acquire+0x2e0e/0x3f20 syzkaller/managers/linux-4-14/kernel/kernel/locking/lockdep.c:3491 lock_acquire+0x170/0x3f0 syzkaller/managers/linux-4-14/kernel/kernel/locking/lockdep.c:3998 __mutex_lock_common syzkaller/managers/linux-4-14/kernel/kernel/locking/mutex.c:756 [inline] __mutex_lock+0xc4/0x1310 syzkaller/managers/linux-4-14/kernel/kernel/locking/mutex.c:893 perf_read_group syzkaller/managers/linux-4-14/kernel/kernel/events/core.c:4542 [inline] __perf_read syzkaller/managers/linux-4-14/kernel/kernel/events/core.c:4624 [inline] perf_read+0x2a2/0x7c0 syzkaller/managers/linux-4-14/kernel/kernel/events/core.c:4639 __vfs_read+0xe4/0x620 syzkaller/managers/linux-4-14/kernel/fs/read_write.c:411 vfs_read+0x139/0x340 syzkaller/managers/linux-4-14/kernel/fs/read_write.c:447 SYSC_read syzkaller/managers/linux-4-14/kernel/fs/read_write.c:574 [inline] SyS_read+0xf2/0x210 syzkaller/managers/linux-4-14/kernel/fs/read_write.c:567 do_syscall_64+0x1d5/0x640 syzkaller/managers/linux-4-14/kernel/arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x465b09 RSP: 002b:00007f6d6d1f0188 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000465b09 RDX: 0000000000002020 RSI: 00000000200020c0 RDI: 0000000000000003 RBP: 00000000004b069f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60 R13: 00007fff1d18d7cf R14: 00007f6d6d1f0300 R15: 0000000000022000 nvme_fabrics: missing parameter 'transport=%s' audit: type=1800 audit(1612954139.360:1122): pid=1607 uid=0 auid=4294967295 ses=4294967295 op="collect_data" cause="failed(directio)" comm="syz-executor.1" name="file0" dev="sda1" ino=17617 res=0 nvme_fabrics: missing parameter 'nqn=%s' audit: type=1800 audit(1612954139.390:1123): pid=1607 uid=0 auid=4294967295 ses=4294967295 op="collect_data" cause="failed(directio)" comm="syz-executor.1" name="file0" dev="sda1" ino=17617 res=0 vhci_hcd vhci_hcd.0: pdev(1) rhport(0) sockfd(4) vhci_hcd vhci_hcd.0: devid(0) speed(1) speed_str(low-speed) vhci_hcd: connection closed vhci_hcd: stop threads vhci_hcd: release socket vhci_hcd: disconnect device nvme_fabrics: missing parameter 'transport=%s' nvme_fabrics: missing parameter 'nqn=%s' ubi: mtd0 is already attached to ubi0 nvme_fabrics: missing parameter 'transport=%s' vhci_hcd vhci_hcd.0: pdev(1) rhport(0) sockfd(4) vhci_hcd vhci_hcd.0: devid(0) speed(1) speed_str(low-speed) nvme_fabrics: missing parameter 'nqn=%s' ubi: mtd0 is already attached to ubi0 nvme_fabrics: missing parameter 'transport=%s' nvme_fabrics: missing parameter 'nqn=%s' vhci_hcd: connection closed vhci_hcd: stop threads vhci_hcd: release socket vhci_hcd: disconnect device ubi: mtd0 is already attached to ubi0 EXT4-fs error (device sda1): ext4_readdir:240: inode #11: block 8227: comm syz-executor.3: path /lost+found: bad entry in directory: inode out of bounds - offset=1, inode=201326592, rec_len=256, name_len=2, size=4096 EXT4-fs error (device sda1): ext4_readdir:240: inode #11: block 8227: comm syz-executor.3: path /lost+found: bad entry in directory: inode out of bounds - offset=1, inode=201326592, rec_len=256, name_len=2, size=4096 nvme_fabrics: missing parameter 'transport=%s' nvme_fabrics: missing parameter 'nqn=%s' vhci_hcd vhci_hcd.0: pdev(1) rhport(0) sockfd(4) vhci_hcd vhci_hcd.0: devid(0) speed(1) speed_str(low-speed) nvme_fabrics: missing parameter 'transport=%s' ubi: mtd0 is already attached to ubi0 vhci_hcd: connection closed vhci_hcd: stop threads EXT4-fs error (device sda1): ext4_readdir:240: inode #11: block 8227: comm syz-executor.3: path /lost+found: bad entry in directory: inode out of bounds - offset=1, inode=201326592, rec_len=256, name_len=2, size=4096 nvme_fabrics: missing parameter 'nqn=%s' vhci_hcd: release socket EXT4-fs error (device sda1): ext4_readdir:240: inode #11: block 8227: comm syz-executor.3: path /lost+found: bad entry in directory: inode out of bounds - offset=1, inode=201326592, rec_len=256, name_len=2, size=4096 vhci_hcd: disconnect device nvme_fabrics: missing parameter 'transport=%s' nvme_fabrics: missing parameter 'nqn=%s' ubi: mtd0 is already attached to ubi0 vhci_hcd vhci_hcd.0: pdev(1) rhport(0) sockfd(4) vhci_hcd vhci_hcd.0: devid(0) speed(1) speed_str(low-speed) nvme_fabrics: missing parameter 'transport=%s' vhci_hcd: connection closed vhci_hcd: stop threads vhci_hcd: release socket vhci_hcd: disconnect device nvme_fabrics: missing parameter 'nqn=%s'