====================================================== WARNING: possible circular locking dependency detected 4.14.141+ #0 Not tainted ------------------------------------------------------ syz-executor.5/2965 is trying to acquire lock: (&cpuctx_mutex/1){+.+.}, at: [<00000000d8c2ff6d>] mutex_lock_double kernel/events/core.c:9909 [inline] (&cpuctx_mutex/1){+.+.}, at: [<00000000d8c2ff6d>] __perf_event_ctx_lock_double kernel/events/core.c:9968 [inline] (&cpuctx_mutex/1){+.+.}, at: [<00000000d8c2ff6d>] SYSC_perf_event_open kernel/events/core.c:10233 [inline] (&cpuctx_mutex/1){+.+.}, at: [<00000000d8c2ff6d>] SyS_perf_event_open+0x12cf/0x2560 kernel/events/core.c:9988 but task is already holding lock: (&cpuctx_mutex){+.+.}, at: [<000000001222bd6c>] mutex_lock_double kernel/events/core.c:9908 [inline] (&cpuctx_mutex){+.+.}, at: [<000000001222bd6c>] __perf_event_ctx_lock_double kernel/events/core.c:9968 [inline] (&cpuctx_mutex){+.+.}, at: [<000000001222bd6c>] SYSC_perf_event_open kernel/events/core.c:10233 [inline] (&cpuctx_mutex){+.+.}, at: [<000000001222bd6c>] SyS_perf_event_open+0x12c2/0x2560 kernel/events/core.c:9988 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&cpuctx_mutex){+.+.}: __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0xf7/0x13e0 kernel/locking/mutex.c:893 perf_event_init_cpu+0xa8/0x150 kernel/events/core.c:11231 perf_event_init+0x289/0x2c5 kernel/events/core.c:11278 start_kernel+0x583/0x890 init/main.c:645 secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:240 -> #1 (pmus_lock){+.+.}: __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0xf7/0x13e0 kernel/locking/mutex.c:893 swevent_hlist_get kernel/events/core.c:7896 [inline] perf_swevent_init+0x123/0x4f0 kernel/events/core.c:7956 perf_try_init_event+0xe5/0x200 kernel/events/core.c:9347 perf_init_event kernel/events/core.c:9385 [inline] perf_event_alloc.part.0+0xd13/0x1ff0 kernel/events/core.c:9645 perf_event_alloc kernel/events/core.c:9998 [inline] SYSC_perf_event_open kernel/events/core.c:10105 [inline] SyS_perf_event_open+0x6eb/0x2560 kernel/events/core.c:9988 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 -> #0 (&cpuctx_mutex/1){+.+.}: lock_acquire+0x12b/0x360 kernel/locking/lockdep.c:3991 __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0xf7/0x13e0 kernel/locking/mutex.c:893 mutex_lock_double kernel/events/core.c:9909 [inline] __perf_event_ctx_lock_double kernel/events/core.c:9968 [inline] SYSC_perf_event_open kernel/events/core.c:10233 [inline] SyS_perf_event_open+0x12cf/0x2560 kernel/events/core.c:9988 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 other info that might help us debug this: Chain exists of: &cpuctx_mutex/1 --> pmus_lock --> &cpuctx_mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&cpuctx_mutex); lock(pmus_lock); lock(&cpuctx_mutex); lock(&cpuctx_mutex/1); *** DEADLOCK *** 1 lock held by syz-executor.5/2965: #0: (&cpuctx_mutex){+.+.}, at: [<000000001222bd6c>] mutex_lock_double kernel/events/core.c:9908 [inline] #0: (&cpuctx_mutex){+.+.}, at: [<000000001222bd6c>] __perf_event_ctx_lock_double kernel/events/core.c:9968 [inline] #0: (&cpuctx_mutex){+.+.}, at: [<000000001222bd6c>] SYSC_perf_event_open kernel/events/core.c:10233 [inline] #0: (&cpuctx_mutex){+.+.}, at: [<000000001222bd6c>] SyS_perf_event_open+0x12c2/0x2560 kernel/events/core.c:9988 stack backtrace: CPU: 0 PID: 2965 Comm: syz-executor.5 Not tainted 4.14.141+ #0 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0xca/0x134 lib/dump_stack.c:53 print_circular_bug.isra.0.cold+0x2dc/0x425 kernel/locking/lockdep.c:1258 check_prev_add kernel/locking/lockdep.c:1901 [inline] check_prevs_add kernel/locking/lockdep.c:2018 [inline] validate_chain kernel/locking/lockdep.c:2460 [inline] __lock_acquire+0x2f5f/0x4320 kernel/locking/lockdep.c:3487 lock_acquire+0x12b/0x360 kernel/locking/lockdep.c:3991 __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0xf7/0x13e0 kernel/locking/mutex.c:893 mutex_lock_double kernel/events/core.c:9909 [inline] __perf_event_ctx_lock_double kernel/events/core.c:9968 [inline] SYSC_perf_event_open kernel/events/core.c:10233 [inline] SyS_perf_event_open+0x12cf/0x2560 kernel/events/core.c:9988 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x459879 RSP: 002b:00007f831212fc78 EFLAGS: 00000246 ORIG_RAX: 000000000000012a RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 0000000000459879 RDX: 0000000000000000 RSI: ffffffffffffffff RDI: 0000000020000200 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000005 R11: 0000000000000246 R12: 00007f83121306d4 R13: 00000000004c66e4 R14: 00000000004db758 R15: 00000000ffffffff netlink: 32 bytes leftover after parsing attributes in process `syz-executor.2'. netlink: 32 bytes leftover after parsing attributes in process `syz-executor.2'. kauditd_printk_skb: 56 callbacks suppressed audit: type=1400 audit(2000000620.510:35954): avc: denied { map } for pid=2999 comm="syz-executor.4" path="/root/syz-executor.4" dev="sda1" ino=16482 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1 audit: type=1400 audit(2000000620.540:35955): avc: denied { map } for pid=2999 comm="syz-executor.4" path="/root/syzkaller-shm431646018" dev="sda1" ino=16494 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1 audit: type=1400 audit(2000000620.570:35956): avc: denied { map } for pid=2999 comm="syz-executor.4" path="/sys/kernel/debug/kcov" dev="debugfs" ino=5044 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:debugfs_t:s0 tclass=file permissive=1 audit: type=1400 audit(2000000620.620:35957): avc: denied { map } for pid=3001 comm="modprobe" path="/bin/kmod" dev="sda1" ino=1440 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1 audit: type=1400 audit(2000000620.650:35958): avc: denied { map } for pid=3002 comm="modprobe" path="/bin/kmod" dev="sda1" ino=1440 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1 audit: type=1400 audit(2000000620.650:35959): avc: denied { map } for pid=3003 comm="modprobe" path="/bin/kmod" dev="sda1" ino=1440 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1 audit: type=1400 audit(2000000620.650:35960): avc: denied { map } for pid=3004 comm="modprobe" path="/bin/kmod" dev="sda1" ino=1440 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1 audit: type=1400 audit(2000000620.650:35961): avc: denied { map } for pid=3004 comm="modprobe" path="/bin/kmod" dev="sda1" ino=1440 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1 audit: type=1400 audit(2000000620.940:35962): avc: denied { map } for pid=3005 comm="modprobe" path="/bin/kmod" dev="sda1" ino=1440 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1 audit: type=1400 audit(2000000620.950:35963): avc: denied { map } for pid=3006 comm="modprobe" path="/bin/kmod" dev="sda1" ino=1440 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1 kauditd_printk_skb: 238 callbacks suppressed audit: type=1400 audit(2000000625.850:36202): avc: denied { map } for pid=3294 comm="blkid" path="/sbin/blkid" dev="sda1" ino=16128 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1 audit: type=1400 audit(2000000625.850:36203): avc: denied { map } for pid=3294 comm="blkid" path="/etc/ld.so.cache" dev="sda1" ino=2503 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1 audit: type=1400 audit(2000000626.000:36204): avc: denied { map } for pid=3303 comm="blkid" path="/sbin/blkid" dev="sda1" ino=16128 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1 audit: type=1400 audit(2000000626.070:36205): avc: denied { map } for pid=3308 comm="blkid" path="/sbin/blkid" dev="sda1" ino=16128 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1 audit: type=1400 audit(2000000626.070:36206): avc: denied { map } for pid=3308 comm="blkid" path="/lib/x86_64-linux-gnu/libuuid.so.1.3.0" dev="sda1" ino=2819 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1 audit: type=1400 audit(2000000626.670:36207): avc: denied { map } for pid=3322 comm="blkid" path="/sbin/blkid" dev="sda1" ino=16128 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1 audit: type=1400 audit(2000000626.690:36208): avc: denied { map } for pid=3322 comm="blkid" path="/sbin/blkid" dev="sda1" ino=16128 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1 audit: type=1400 audit(2000000626.760:36209): avc: denied { map } for pid=3328 comm="blkid" path="/sbin/blkid" dev="sda1" ino=16128 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1 audit: type=1400 audit(2000000626.860:36210): avc: denied { map } for pid=3333 comm="blkid" path="/sbin/blkid" dev="sda1" ino=16128 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1 audit: type=1400 audit(2000000626.880:36211): avc: denied { map } for pid=3333 comm="blkid" path="/sbin/blkid" dev="sda1" ino=16128 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1