====================================================== WARNING: possible circular locking dependency detected 4.15.0-rc2-mm1+ #39 Not tainted ------------------------------------------------------ syz-executor3/15393 is trying to acquire lock: (&ctx->mutex){+.+.}, at: [<0000000028f99319>] perf_event_ctx_lock_nested+0x21b/0x450 kernel/events/core.c:1249 but task is already holding lock: (&pipe->mutex/1){+.+.}, at: [<00000000cdd74cc8>] pipe_lock_nested fs/pipe.c:67 [inline] (&pipe->mutex/1){+.+.}, at: [<00000000cdd74cc8>] pipe_lock+0x56/0x70 fs/pipe.c:75 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #8 (&pipe->mutex/1){+.+.}: lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4004 __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 pipe_lock_nested fs/pipe.c:67 [inline] pipe_lock+0x56/0x70 fs/pipe.c:75 iter_file_splice_write+0x264/0xf30 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/0x96 -> #7 (sb_writers){.+.+}: spin_lock include/linux/spinlock.h:315 [inline] _atomic_dec_and_lock+0x125/0x196 lib/dec_and_lock.c:28 iput+0x13a/0xaf0 fs/inode.c:1532 bdput fs/block_dev.c:923 [inline] bd_forget+0xf0/0x1a0 fs/block_dev.c:983 evict+0x64f/0x920 fs/inode.c:558 iput_final fs/inode.c:1514 [inline] iput+0x7b9/0xaf0 fs/inode.c:1541 -> #6 ((completion)&req.done){+.+.}: lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4004 complete_acquire include/linux/completion.h:40 [inline] __wait_for_common kernel/sched/completion.c:109 [inline] wait_for_common kernel/sched/completion.c:123 [inline] wait_for_completion+0xcb/0x7b0 kernel/sched/completion.c:144 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+0x2ea/0x1d20 kernel/cpu.c:182 cpuhp_thread_fun+0x48e/0x7e0 kernel/cpu.c:571 smpboot_thread_fn+0x450/0x7c0 kernel/smpboot.c:164 kthread+0x37a/0x440 kernel/kthread.c:238 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:524 -> #5 (cpuhp_state-up){+.+.}: lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4004 cpuhp_lock_acquire kernel/cpu.c:85 [inline] cpuhp_invoke_ap_callback kernel/cpu.c:605 [inline] cpuhp_issue_call+0x1e5/0x520 kernel/cpu.c:1495 __cpuhp_setup_state_cpuslocked+0x282/0x600 kernel/cpu.c:1642 __cpuhp_setup_state+0xb0/0x140 kernel/cpu.c:1671 cpuhp_setup_state include/linux/cpuhotplug.h:201 [inline] page_writeback_init+0x4d/0x71 mm/page-writeback.c:2081 pagecache_init+0x48/0x4f mm/filemap.c:976 start_kernel+0x6c1/0x754 init/main.c:697 x86_64_start_reservations+0x2a/0x2c arch/x86/kernel/head64.c:378 x86_64_start_kernel+0x77/0x7a arch/x86/kernel/head64.c:359 secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:237 -> #4 (cpuhp_state_mutex){+.+.}: lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4004 __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 __cpuhp_setup_state_cpuslocked+0x5b/0x600 kernel/cpu.c:1617 __cpuhp_setup_state+0xb0/0x140 kernel/cpu.c:1671 cpuhp_setup_state_nocalls include/linux/cpuhotplug.h:229 [inline] kvm_guest_init+0x1f3/0x20f arch/x86/kernel/kvm.c:528 setup_arch+0x17e8/0x1a02 arch/x86/kernel/setup.c:1266 start_kernel+0xa5/0x754 init/main.c:532 x86_64_start_reservations+0x2a/0x2c arch/x86/kernel/head64.c:378 x86_64_start_kernel+0x77/0x7a arch/x86/kernel/head64.c:359 secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:237 -> #3 (cpu_hotplug_lock.rw_sem){++++}: lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4004 percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:36 [inline] percpu_down_read include/linux/percpu-rwsem.h:59 [inline] cpus_read_lock+0x42/0x90 kernel/cpu.c:293 static_key_slow_inc+0x9d/0x3c0 kernel/jump_label.c:123 tracepoint_add_func kernel/tracepoint.c:222 [inline] tracepoint_probe_register_prio+0x80d/0x9a0 kernel/tracepoint.c:282 tracepoint_probe_register+0x2a/0x40 kernel/tracepoint.c:303 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+0x4ef/0xab0 kernel/trace/trace_event_perf.c:221 perf_tp_event_init+0x7d/0xf0 kernel/events/core.c:7956 perf_try_init_event+0xc9/0x1f0 kernel/events/core.c:9182 perf_init_event kernel/events/core.c:9220 [inline] perf_event_alloc+0x1cc6/0x2b00 kernel/events/core.c:9484 SYSC_perf_event_open+0x84e/0x2e00 kernel/events/core.c:9939 SyS_perf_event_open+0x39/0x50 kernel/events/core.c:9825 entry_SYSCALL_64_fastpath+0x1f/0x96 -> #2 (tracepoints_mutex){+.+.}: lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4004 __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 tracepoint_probe_register_prio+0xa0/0x9a0 kernel/tracepoint.c:278 tracepoint_probe_register+0x2a/0x40 kernel/tracepoint.c:303 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+0x4ef/0xab0 kernel/trace/trace_event_perf.c:221 perf_tp_event_init+0x7d/0xf0 kernel/events/core.c:7956 perf_try_init_event+0xc9/0x1f0 kernel/events/core.c:9182 perf_init_event kernel/events/core.c:9220 [inline] perf_event_alloc+0x1cc6/0x2b00 kernel/events/core.c:9484 SYSC_perf_event_open+0x84e/0x2e00 kernel/events/core.c:9939 SyS_perf_event_open+0x39/0x50 kernel/events/core.c:9825 entry_SYSCALL_64_fastpath+0x1f/0x96 -> #1 (event_mutex){+.+.}: lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4004 __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 perf_trace_init+0x58/0xab0 kernel/trace/trace_event_perf.c:216 perf_tp_event_init+0x7d/0xf0 kernel/events/core.c:7956 perf_try_init_event+0xc9/0x1f0 kernel/events/core.c:9182 perf_init_event kernel/events/core.c:9204 [inline] perf_event_alloc+0x1005/0x2b00 kernel/events/core.c:9484 inherit_event.isra.92+0x15b/0x920 kernel/events/core.c:10698 inherit_group kernel/events/core.c:10789 [inline] inherit_task_group.isra.94.part.95+0x73/0x240 kernel/events/core.c:10847 inherit_task_group kernel/events/core.c:10827 [inline] perf_event_init_context kernel/events/core.c:10898 [inline] perf_event_init_task+0x348/0x890 kernel/events/core.c:10966 copy_process.part.35+0x1748/0x4b30 kernel/fork.c:1780 copy_process kernel/fork.c:1619 [inline] _do_fork+0x1ef/0xf10 kernel/fork.c:2100 SYSC_clone kernel/fork.c:2208 [inline] SyS_clone+0x37/0x50 kernel/fork.c:2202 do_syscall_64+0x26c/0x920 arch/x86/entry/common.c:285 return_from_SYSCALL_64+0x0/0x75 -> #0 (&ctx->mutex){+.+.}: check_prevs_add kernel/locking/lockdep.c:2031 [inline] validate_chain kernel/locking/lockdep.c:2473 [inline] __lock_acquire+0x3498/0x47f0 kernel/locking/lockdep.c:3500 lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4004 __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 perf_event_ctx_lock_nested+0x21b/0x450 kernel/events/core.c:1249 perf_event_ctx_lock kernel/events/core.c:1262 [inline] perf_read+0xb9/0x970 kernel/events/core.c:4507 do_loop_readv_writev fs/read_write.c:673 [inline] do_iter_read+0x3db/0x5b0 fs/read_write.c:897 vfs_readv+0x121/0x1c0 fs/read_write.c:959 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/0x96 other info that might help us debug this: Chain exists of: &ctx->mutex --> sb_writers --> &pipe->mutex/1 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&pipe->mutex/1); lock(sb_writers); lock(&pipe->mutex/1); lock(&ctx->mutex); *** DEADLOCK *** 1 lock held by syz-executor3/15393: #0: (&pipe->mutex/1){+.+.}, at: [<00000000cdd74cc8>] pipe_lock_nested fs/pipe.c:67 [inline] #0: (&pipe->mutex/1){+.+.}, at: [<00000000cdd74cc8>] pipe_lock+0x56/0x70 fs/pipe.c:75 stack backtrace: CPU: 1 PID: 15393 Comm: syz-executor3 Not tainted 4.15.0-rc2-mm1+ #39 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:53 print_circular_bug+0x42d/0x610 kernel/locking/lockdep.c:1271 check_prev_add+0x666/0x15f0 kernel/locking/lockdep.c:1914 check_prevs_add kernel/locking/lockdep.c:2031 [inline] validate_chain kernel/locking/lockdep.c:2473 [inline] __lock_acquire+0x3498/0x47f0 kernel/locking/lockdep.c:3500 lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4004 __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 perf_event_ctx_lock_nested+0x21b/0x450 kernel/events/core.c:1249 perf_event_ctx_lock kernel/events/core.c:1262 [inline] perf_read+0xb9/0x970 kernel/events/core.c:4507 do_loop_readv_writev fs/read_write.c:673 [inline] do_iter_read+0x3db/0x5b0 fs/read_write.c:897 vfs_readv+0x121/0x1c0 fs/read_write.c:959 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/0x96 RIP: 0033:0x452a39 RSP: 002b:00007f8c89331c58 EFLAGS: 00000212 ORIG_RAX: 0000000000000113 RAX: ffffffffffffffda RBX: 0000000000758020 RCX: 0000000000452a39 RDX: 0000000000000017 RSI: 0000000000000000 RDI: 0000000000000013 RBP: 0000000000000598 R08: 0000000000005515 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006f66e0 R13: 00000000ffffffff R14: 00007f8c893326d4 R15: 0000000000000000 QAT: Invalid ioctl QAT: Invalid ioctl QAT: Invalid ioctl QAT: Invalid ioctl QAT: Invalid ioctl QAT: Invalid ioctl QAT: Invalid ioctl QAT: Invalid ioctl device gre0 left promiscuous mode nla_parse: 13 callbacks suppressed netlink: 8 bytes leftover after parsing attributes in process `syz-executor1'. netlink: 8 bytes leftover after parsing attributes in process `syz-executor1'. netlink: 9 bytes leftover after parsing attributes in process `syz-executor4'. A link change request failed with some changes committed already. Interface lo may have been left with an inconsistent configuration, please check. netlink: 9 bytes leftover after parsing attributes in process `syz-executor4'. A link change request failed with some changes committed already. Interface lo may have been left with an inconsistent configuration, please check. netlink: 5 bytes leftover after parsing attributes in process `syz-executor5'. netlink: 5 bytes leftover after parsing attributes in process `syz-executor5'. netlink: 3 bytes leftover after parsing attributes in process `syz-executor5'. netlink: 3 bytes leftover after parsing attributes in process `syz-executor5'. netlink: 3 bytes leftover after parsing attributes in process `syz-executor5'. netlink: 16 bytes leftover after parsing attributes in process `syz-executor1'. binder: 16025:16027 ioctl c0306201 2000ffd0 returned -14 binder: BINDER_SET_CONTEXT_MGR already set binder: 16025:16027 ioctl 40046207 0 returned -16 loop: Write error at byte offset 0, length 512. print_req_error: I/O error, dev loop4, sector 0 Buffer I/O error on dev loop4, logical block 0, lost async page write loop: Write error at byte offset 0, length 512. print_req_error: I/O error, dev loop4, sector 0 Buffer I/O error on dev loop4, logical block 0, lost async page write FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 0 CPU: 1 PID: 16383 Comm: syz-executor3 Not tainted 4.15.0-rc2-mm1+ #39 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:53 fail_dump lib/fault-inject.c:51 [inline] should_fail+0x8c0/0xa40 lib/fault-inject.c:149 should_failslab+0xec/0x120 mm/failslab.c:32 slab_pre_alloc_hook mm/slab.h:425 [inline] slab_alloc mm/slab.c:3372 [inline] kmem_cache_alloc_trace+0x4b/0x750 mm/slab.c:3612 kmalloc include/linux/slab.h:516 [inline] kzalloc include/linux/slab.h:705 [inline] alloc_pipe_info+0xb1/0x350 fs/pipe.c:628 splice_direct_to_actor+0x650/0x820 fs/splice.c:920 do_splice_direct+0x2a7/0x3d0 fs/splice.c:1061 do_sendfile+0x5d5/0xe90 fs/read_write.c:1413 SYSC_sendfile64 fs/read_write.c:1468 [inline] SyS_sendfile64+0xbd/0x160 fs/read_write.c:1460 entry_SYSCALL_64_fastpath+0x1f/0x96 RIP: 0033:0x452a39 RSP: 002b:00007f8c89331c58 EFLAGS: 00000212 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 0000000000758020 RCX: 0000000000452a39 RDX: 00000000201c9000 RSI: 0000000000000013 RDI: 0000000000000013 RBP: 00000000000003f2 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000000003ff R11: 0000000000000212 R12: 00000000006f3f50 R13: 00000000ffffffff R14: 00007f8c893326d4 R15: 0000000000000000 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=18176 sclass=netlink_route_socket pig=16460 comm=syz-executor6 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=18176 sclass=netlink_route_socket pig=16467 comm=syz-executor6 nla_parse: 41 callbacks suppressed netlink: 3 bytes leftover after parsing attributes in process `syz-executor5'. netlink: 3 bytes leftover after parsing attributes in process `syz-executor5'. netlink: 3 bytes leftover after parsing attributes in process `syz-executor5'. netlink: 3 bytes leftover after parsing attributes in process `syz-executor5'. netlink: 3 bytes leftover after parsing attributes in process `syz-executor5'. netlink: 3 bytes leftover after parsing attributes in process `syz-executor5'. netlink: 3 bytes leftover after parsing attributes in process `syz-executor5'. netlink: 3 bytes leftover after parsing attributes in process `syz-executor5'. netlink: 3 bytes leftover after parsing attributes in process `syz-executor5'. netlink: 3 bytes leftover after parsing attributes in process `syz-executor5'. SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket pig=16834 comm=syz-executor6 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket pig=16844 comm=syz-executor6 audit: type=1400 audit(1513229908.320:1172): avc: denied { map } for pid=16860 comm="syz-executor3" path="/proc/1535" dev="proc" ino=60372 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=dir permissive=1