====================================================== WARNING: possible circular locking dependency detected 4.13.0-next-20170912+ #20 Not tainted ------------------------------------------------------ syz-executor4/3313 is trying to acquire lock: (event_mutex){+.+.}, at: [] ftrace_profile_set_filter+0x7a/0x270 kernel/trace/trace_events_filter.c:2266 but task is already holding lock: (&ctx->mutex){+.+.}, at: [] perf_event_ctx_lock_nested+0x1dc/0x3c0 kernel/events/core.c:1210 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #8 (&ctx->mutex){+.+.}: check_prevs_add kernel/locking/lockdep.c:2020 [inline] validate_chain kernel/locking/lockdep.c:2469 [inline] __lock_acquire+0x328f/0x4620 kernel/locking/lockdep.c:3498 lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4002 __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0x16f/0x1870 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 perf_event_ctx_lock_nested+0x1dc/0x3c0 kernel/events/core.c:1210 perf_event_ctx_lock kernel/events/core.c:1223 [inline] perf_read+0xb9/0x970 kernel/events/core.c:4584 do_loop_readv_writev fs/read_write.c:693 [inline] do_iter_read+0x3db/0x5b0 fs/read_write.c:917 vfs_readv+0x121/0x1c0 fs/read_write.c:979 kernel_readv fs/splice.c:361 [inline] default_file_splice_read+0x508/0xae0 fs/splice.c:416 do_splice_to+0x110/0x170 fs/splice.c:880 do_splice fs/splice.c:1173 [inline] SYSC_splice fs/splice.c:1402 [inline] SyS_splice+0x11a8/0x1630 fs/splice.c:1382 entry_SYSCALL_64_fastpath+0x1f/0xbe -> #7 (&pipe->mutex/1){+.+.}: check_prevs_add kernel/locking/lockdep.c:2020 [inline] validate_chain kernel/locking/lockdep.c:2469 [inline] __lock_acquire+0x328f/0x4620 kernel/locking/lockdep.c:3498 lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4002 __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0x16f/0x1870 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 pipe_lock_nested fs/pipe.c:66 [inline] pipe_lock+0x56/0x70 fs/pipe.c:74 iter_file_splice_write+0x264/0xf50 fs/splice.c:699 do_splice_from fs/splice.c:851 [inline] do_splice fs/splice.c:1147 [inline] SYSC_splice fs/splice.c:1402 [inline] SyS_splice+0x7d5/0x1630 fs/splice.c:1382 entry_SYSCALL_64_fastpath+0x1f/0xbe -> #6 (sb_writers){.+.+}: percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:35 [inline] percpu_down_read include/linux/percpu-rwsem.h:58 [inline] __sb_start_write+0x18f/0x290 fs/super.c:1341 sb_start_write include/linux/fs.h:1541 [inline] mnt_want_write+0x3f/0xb0 fs/namespace.c:387 filename_create+0x12b/0x520 fs/namei.c:3628 kern_path_create+0x33/0x40 fs/namei.c:3674 handle_create+0xc0/0x760 drivers/base/devtmpfs.c:203 -> #5 ((complete)&req.done){+.+.}: check_prevs_add kernel/locking/lockdep.c:2020 [inline] validate_chain kernel/locking/lockdep.c:2469 [inline] __lock_acquire+0x328f/0x4620 kernel/locking/lockdep.c:3498 lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4002 complete_acquire include/linux/completion.h:39 [inline] __wait_for_common kernel/sched/completion.c:108 [inline] wait_for_common kernel/sched/completion.c:122 [inline] wait_for_completion+0xc8/0x770 kernel/sched/completion.c:143 devtmpfs_create_node+0x32b/0x4a0 drivers/base/devtmpfs.c:115 device_add+0x120f/0x1640 drivers/base/core.c:1824 device_create_groups_vargs+0x1f3/0x250 drivers/base/core.c:2430 device_create_vargs drivers/base/core.c:2470 [inline] device_create+0xda/0x110 drivers/base/core.c:2506 msr_device_create+0x26/0x40 arch/x86/kernel/msr.c:188 cpuhp_invoke_callback+0x256/0x14d0 kernel/cpu.c:145 cpuhp_thread_fun+0x265/0x520 kernel/cpu.c:434 smpboot_thread_fn+0x489/0x850 kernel/smpboot.c:164 kthread+0x39c/0x470 kernel/kthread.c:231 ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:431 -> #4 (cpuhp_state){+.+.}: check_prevs_add kernel/locking/lockdep.c:2020 [inline] validate_chain kernel/locking/lockdep.c:2469 [inline] __lock_acquire+0x328f/0x4620 kernel/locking/lockdep.c:3498 lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4002 cpuhp_invoke_ap_callback kernel/cpu.c:467 [inline] cpuhp_issue_call+0x1a2/0x3e0 kernel/cpu.c:1308 __cpuhp_setup_state_cpuslocked+0x2d6/0x5f0 kernel/cpu.c:1455 __cpuhp_setup_state+0xb0/0x140 kernel/cpu.c:1484 cpuhp_setup_state include/linux/cpuhotplug.h:177 [inline] page_writeback_init+0x4d/0x71 mm/page-writeback.c:2082 pagecache_init+0x48/0x4f mm/filemap.c:871 start_kernel+0x6c1/0x754 init/main.c:690 x86_64_start_reservations+0x2a/0x2c arch/x86/kernel/head64.c:377 x86_64_start_kernel+0x87/0x8a arch/x86/kernel/head64.c:358 verify_cpu+0x0/0xfb -> #3 (cpuhp_state_mutex){+.+.}: check_prevs_add kernel/locking/lockdep.c:2020 [inline] validate_chain kernel/locking/lockdep.c:2469 [inline] __lock_acquire+0x328f/0x4620 kernel/locking/lockdep.c:3498 lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4002 __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0x16f/0x1870 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 __cpuhp_setup_state_cpuslocked+0x5b/0x5f0 kernel/cpu.c:1430 __cpuhp_setup_state+0xb0/0x140 kernel/cpu.c:1484 cpuhp_setup_state_nocalls include/linux/cpuhotplug.h:205 [inline] kvm_guest_init+0x1f3/0x20f arch/x86/kernel/kvm.c:488 setup_arch+0x1899/0x1ab3 arch/x86/kernel/setup.c:1295 start_kernel+0xa5/0x754 init/main.c:530 x86_64_start_reservations+0x2a/0x2c arch/x86/kernel/head64.c:377 x86_64_start_kernel+0x87/0x8a arch/x86/kernel/head64.c:358 verify_cpu+0x0/0xfb -> #2 (cpu_hotplug_lock.rw_sem){++++}: check_prevs_add kernel/locking/lockdep.c:2020 [inline] validate_chain kernel/locking/lockdep.c:2469 [inline] __lock_acquire+0x328f/0x4620 kernel/locking/lockdep.c:3498 lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4002 percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:35 [inline] percpu_down_read include/linux/percpu-rwsem.h:58 [inline] cpus_read_lock+0x42/0x90 kernel/cpu.c:218 static_key_slow_inc+0x9d/0x3c0 kernel/jump_label.c:123 tracepoint_add_func kernel/tracepoint.c:223 [inline] tracepoint_probe_register_prio+0x80d/0x9a0 kernel/tracepoint.c:283 tracepoint_probe_register+0x2a/0x40 kernel/tracepoint.c:304 trace_event_reg+0x167/0x320 kernel/trace/trace_events.c:305 perf_trace_event_reg kernel/trace/trace_event_perf.c:122 [inline] perf_trace_event_init kernel/trace/trace_event_perf.c:197 [inline] perf_trace_init+0x4f9/0xab0 kernel/trace/trace_event_perf.c:221 perf_tp_event_init+0x7d/0xf0 kernel/events/core.c:8037 perf_try_init_event+0xc9/0x1f0 kernel/events/core.c:9261 perf_init_event kernel/events/core.c:9299 [inline] perf_event_alloc+0x1c5b/0x2a00 kernel/events/core.c:9558 SYSC_perf_event_open+0x84e/0x2e00 kernel/events/core.c:10013 SyS_perf_event_open+0x39/0x50 kernel/events/core.c:9899 entry_SYSCALL_64_fastpath+0x1f/0xbe -> #1 (tracepoints_mutex){+.+.}: check_prevs_add kernel/locking/lockdep.c:2020 [inline] validate_chain kernel/locking/lockdep.c:2469 [inline] __lock_acquire+0x328f/0x4620 kernel/locking/lockdep.c:3498 lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4002 __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0x16f/0x1870 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 tracepoint_probe_register_prio+0xa0/0x9a0 kernel/tracepoint.c:279 tracepoint_probe_register+0x2a/0x40 kernel/tracepoint.c:304 trace_event_reg+0x167/0x320 kernel/trace/trace_events.c:305 perf_trace_event_reg kernel/trace/trace_event_perf.c:122 [inline] perf_trace_event_init kernel/trace/trace_event_perf.c:197 [inline] perf_trace_init+0x4f9/0xab0 kernel/trace/trace_event_perf.c:221 perf_tp_event_init+0x7d/0xf0 kernel/events/core.c:8037 perf_try_init_event+0xc9/0x1f0 kernel/events/core.c:9261 perf_init_event kernel/events/core.c:9299 [inline] perf_event_alloc+0x1c5b/0x2a00 kernel/events/core.c:9558 SYSC_perf_event_open+0x84e/0x2e00 kernel/events/core.c:10013 SyS_perf_event_open+0x39/0x50 kernel/events/core.c:9899 entry_SYSCALL_64_fastpath+0x1f/0xbe -> #0 (event_mutex){+.+.}: check_prev_add+0x865/0x1520 kernel/locking/lockdep.c:1894 check_prevs_add kernel/locking/lockdep.c:2020 [inline] validate_chain kernel/locking/lockdep.c:2469 [inline] __lock_acquire+0x328f/0x4620 kernel/locking/lockdep.c:3498 lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4002 __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0x16f/0x1870 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 ftrace_profile_set_filter+0x7a/0x270 kernel/trace/trace_events_filter.c:2266 perf_event_set_filter kernel/events/core.c:8622 [inline] _perf_ioctl kernel/events/core.c:4785 [inline] perf_ioctl+0x1026/0x1360 kernel/events/core.c:4822 vfs_ioctl fs/ioctl.c:45 [inline] do_vfs_ioctl+0x1b1/0x1530 fs/ioctl.c:685 SYSC_ioctl fs/ioctl.c:700 [inline] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:691 entry_SYSCALL_64_fastpath+0x1f/0xbe other info that might help us debug this: Chain exists of: event_mutex --> &pipe->mutex/1 --> &ctx->mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&ctx->mutex); lock(&pipe->mutex/1); lock(&ctx->mutex); lock(event_mutex); *** DEADLOCK *** 1 lock held by syz-executor4/3313: #0: (&ctx->mutex){+.+.}, at: [] perf_event_ctx_lock_nested+0x1dc/0x3c0 kernel/events/core.c:1210 stack backtrace: CPU: 1 PID: 3313 Comm: syz-executor4 Not tainted 4.13.0-next-20170912+ #20 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:16 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:52 print_circular_bug+0x503/0x710 kernel/locking/lockdep.c:1259 check_prev_add+0x865/0x1520 kernel/locking/lockdep.c:1894 check_prevs_add kernel/locking/lockdep.c:2020 [inline] validate_chain kernel/locking/lockdep.c:2469 [inline] __lock_acquire+0x328f/0x4620 kernel/locking/lockdep.c:3498 lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4002 __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0x16f/0x1870 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 ftrace_profile_set_filter+0x7a/0x270 kernel/trace/trace_events_filter.c:2266 perf_event_set_filter kernel/events/core.c:8622 [inline] _perf_ioctl kernel/events/core.c:4785 [inline] perf_ioctl+0x1026/0x1360 kernel/events/core.c:4822 vfs_ioctl fs/ioctl.c:45 [inline] do_vfs_ioctl+0x1b1/0x1530 fs/ioctl.c:685 SYSC_ioctl fs/ioctl.c:700 [inline] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:691 entry_SYSCALL_64_fastpath+0x1f/0xbe RIP: 0033:0x451e59 RSP: 002b:00007fc2f55a7c08 EFLAGS: 00000216 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000718000 RCX: 0000000000451e59 RDX: 00000000208bb000 RSI: 0000000040082406 RDI: 0000000000000006 RBP: 0000000000000082 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000216 R12: 0000000000000000 R13: 0000000000a6f7ef R14: 00007fc2f55a89c0 R15: 0000000000000000 mmap: syz-executor5 (3330) uses deprecated remap_file_pages() syscall. See Documentation/vm/remap_file_pages.txt. capability: warning: `syz-executor0' uses deprecated v2 capabilities in a way that may be insecure FAULT_INJECTION: forcing a failure. name fail_page_alloc, interval 1, probability 0, space 0, times 1 CPU: 1 PID: 4181 Comm: syz-executor5 Not tainted 4.13.0-next-20170912+ #20 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:16 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:52 fail_dump lib/fault-inject.c:51 [inline] should_fail+0x8c0/0xa40 lib/fault-inject.c:149 should_fail_alloc_page mm/page_alloc.c:2915 [inline] prepare_alloc_pages mm/page_alloc.c:4151 [inline] __alloc_pages_nodemask+0x338/0xd80 mm/page_alloc.c:4187 alloc_pages_current+0xb6/0x1e0 mm/mempolicy.c:2035 alloc_pages include/linux/gfp.h:505 [inline] skb_page_frag_refill+0x358/0x5f0 net/core/sock.c:2196 tun_build_skb.isra.42+0x2a2/0x1690 drivers/net/tun.c:1289 tun_get_user+0x1dad/0x2150 drivers/net/tun.c:1455 tun_chr_write_iter+0xde/0x190 drivers/net/tun.c:1579 call_write_iter include/linux/fs.h:1770 [inline] new_sync_write fs/read_write.c:468 [inline] __vfs_write+0x68a/0x970 fs/read_write.c:481 vfs_write+0x18f/0x510 fs/read_write.c:543 SYSC_write fs/read_write.c:588 [inline] SyS_write+0xef/0x220 fs/read_write.c:580 entry_SYSCALL_64_fastpath+0x1f/0xbe RIP: 0033:0x40c2c1 RSP: 002b:00007f8bf0184c10 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000718000 RCX: 000000000040c2c1 RDX: 000000000000003e RSI: 0000000020d67f77 RDI: 0000000000000015 RBP: 00007f8bf0184a10 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000000f4240 R11: 0000000000000293 R12: 00000000004b69f7 R13: 00007f8bf0184b48 R14: 00000000004b6a07 R15: 0000000000000000 FAULT_INJECTION: forcing a failure. name fail_page_alloc, interval 1, probability 0, space 0, times 0 CPU: 0 PID: 4341 Comm: syz-executor4 Not tainted 4.13.0-next-20170912+ #20 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:16 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:52 fail_dump lib/fault-inject.c:51 [inline] should_fail+0x8c0/0xa40 lib/fault-inject.c:149 should_fail_alloc_page mm/page_alloc.c:2915 [inline] prepare_alloc_pages mm/page_alloc.c:4151 [inline] __alloc_pages_nodemask+0x338/0xd80 mm/page_alloc.c:4187 alloc_pages_current+0xb6/0x1e0 mm/mempolicy.c:2035 alloc_pages include/linux/gfp.h:505 [inline] skb_page_frag_refill+0x358/0x5f0 net/core/sock.c:2196 tun_build_skb.isra.42+0x2a2/0x1690 drivers/net/tun.c:1289 tun_get_user+0x1dad/0x2150 drivers/net/tun.c:1455 tun_chr_write_iter+0xde/0x190 drivers/net/tun.c:1579 call_write_iter include/linux/fs.h:1770 [inline] new_sync_write fs/read_write.c:468 [inline] __vfs_write+0x68a/0x970 fs/read_write.c:481 vfs_write+0x18f/0x510 fs/read_write.c:543 SYSC_write fs/read_write.c:588 [inline] SyS_write+0xef/0x220 fs/read_write.c:580 entry_SYSCALL_64_fastpath+0x1f/0xbe RIP: 0033:0x40c2c1 RSP: 002b:00007fc2f55a7c10 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000718000 RCX: 000000000040c2c1 RDX: 0000000000000046 RSI: 0000000020000000 RDI: 0000000000000015 RBP: 00007fc2f55a7a10 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000000f4240 R11: 0000000000000293 R12: 00000000004b69f7 R13: 00007fc2f55a7b48 R14: 00000000004b6a07 R15: 0000000000000000 netlink: 2 bytes leftover after parsing attributes in process `syz-executor5'. IPv6: Can't replace route, no match found netlink: 2 bytes leftover after parsing attributes in process `syz-executor5'. IPv6: Can't replace route, no match found capability: warning: `syz-executor5' uses 32-bit capabilities (legacy support in use) audit: type=1326 audit(1505239333.837:2): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=5973 comm="syz-executor4" exe="/root/syz-executor4" sig=31 arch=c000003e syscall=202 compat=0 ip=0x451e59 code=0xffff0000 audit: type=1326 audit(1505239333.922:3): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=5973 comm="syz-executor4" exe="/root/syz-executor4" sig=31 arch=c000003e syscall=202 compat=0 ip=0x451e59 code=0xffff0000