====================================================== WARNING: possible circular locking dependency detected 4.14.198-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.1/29078 is trying to acquire lock: (&event->child_mutex){+.+.}, at: [] perf_read_group kernel/events/core.c:4541 [inline] (&event->child_mutex){+.+.}, at: [] __perf_read kernel/events/core.c:4623 [inline] (&event->child_mutex){+.+.}, at: [] perf_read+0x2a2/0x7c0 kernel/events/core.c:4638 but task is already holding lock: (&cpuctx_mutex){+.+.}, at: [] perf_event_ctx_lock_nested+0x14d/0x2c0 kernel/events/core.c:1240 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #5 (&cpuctx_mutex){+.+.}: __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0xc4/0x1310 kernel/locking/mutex.c:893 perf_event_init_cpu+0xb7/0x170 kernel/events/core.c:11249 perf_event_init+0x2cc/0x308 kernel/events/core.c:11296 start_kernel+0x46a/0x770 init/main.c:620 secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:240 -> #4 (pmus_lock){+.+.}: __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0xc4/0x1310 kernel/locking/mutex.c:893 perf_event_init_cpu+0x2c/0x170 kernel/events/core.c:11243 cpuhp_invoke_callback+0x1e6/0x1a80 kernel/cpu.c:184 cpuhp_up_callbacks kernel/cpu.c:572 [inline] _cpu_up+0x219/0x500 kernel/cpu.c:1140 do_cpu_up+0x9a/0x160 kernel/cpu.c:1175 smp_init+0x197/0x1ac kernel/smp.c:578 kernel_init_freeable+0x3f4/0x619 init/main.c:1068 kernel_init+0xd/0x15b init/main.c:1000 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 -> #3 (cpu_hotplug_lock.rw_sem){++++}: 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+0x39/0xc0 kernel/cpu.c:295 static_key_slow_inc+0xe/0x20 kernel/jump_label.c:123 tracepoint_add_func+0x517/0x750 kernel/tracepoint.c:223 tracepoint_probe_register_prio kernel/tracepoint.c:283 [inline] tracepoint_probe_register+0x8c/0xc0 kernel/tracepoint.c:304 trace_event_reg+0x272/0x330 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+0x424/0xa30 kernel/trace/trace_event_perf.c:221 perf_tp_event_init+0x79/0xf0 kernel/events/core.c:8132 perf_try_init_event+0x15b/0x1f0 kernel/events/core.c:9368 perf_init_event kernel/events/core.c:9406 [inline] perf_event_alloc.part.0+0xe2d/0x2640 kernel/events/core.c:9666 perf_event_alloc kernel/events/core.c:10019 [inline] SYSC_perf_event_open kernel/events/core.c:10123 [inline] SyS_perf_event_open+0x67f/0x24b0 kernel/events/core.c:10009 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb -> #2 (tracepoints_mutex){+.+.}: __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0xc4/0x1310 kernel/locking/mutex.c:893 tracepoint_probe_register_prio kernel/tracepoint.c:279 [inline] tracepoint_probe_register+0x68/0xc0 kernel/tracepoint.c:304 trace_event_reg+0x272/0x330 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+0x424/0xa30 kernel/trace/trace_event_perf.c:221 perf_tp_event_init+0x79/0xf0 kernel/events/core.c:8132 perf_try_init_event+0x15b/0x1f0 kernel/events/core.c:9368 perf_init_event kernel/events/core.c:9406 [inline] perf_event_alloc.part.0+0xe2d/0x2640 kernel/events/core.c:9666 perf_event_alloc kernel/events/core.c:10019 [inline] SYSC_perf_event_open kernel/events/core.c:10123 [inline] SyS_perf_event_open+0x67f/0x24b0 kernel/events/core.c:10009 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb -> #1 (event_mutex){+.+.}: __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0xc4/0x1310 kernel/locking/mutex.c:893 perf_trace_destroy+0x23/0xf0 kernel/trace/trace_event_perf.c:234 _free_event+0x321/0xe20 kernel/events/core.c:4243 free_event+0x32/0x40 kernel/events/core.c:4270 perf_event_release_kernel+0x368/0x8a0 kernel/events/core.c:4414 perf_release+0x33/0x40 kernel/events/core.c:4440 __fput+0x25f/0x7a0 fs/file_table.c:210 task_work_run+0x11f/0x190 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x1ad/0x200 arch/x86/entry/common.c:164 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline] syscall_return_slowpath arch/x86/entry/common.c:270 [inline] do_syscall_64+0x4a3/0x640 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x46/0xbb -> #0 (&event->child_mutex){+.+.}: lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998 __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0xc4/0x1310 kernel/locking/mutex.c:893 perf_read_group kernel/events/core.c:4541 [inline] __perf_read kernel/events/core.c:4623 [inline] perf_read+0x2a2/0x7c0 kernel/events/core.c:4638 do_loop_readv_writev fs/read_write.c:695 [inline] do_loop_readv_writev fs/read_write.c:682 [inline] do_iter_read+0x3eb/0x5b0 fs/read_write.c:919 vfs_readv+0xc8/0x120 fs/read_write.c:981 do_readv+0xfc/0x2c0 fs/read_write.c:1014 do_syscall_64+0x1d5/0x640 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.1/29078: #0: (&cpuctx_mutex){+.+.}, at: [] perf_event_ctx_lock_nested+0x14d/0x2c0 kernel/events/core.c:1240 stack backtrace: CPU: 0 PID: 29078 Comm: syz-executor.1 Not tainted 4.14.198-syzkaller #0 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+0x1b2/0x283 lib/dump_stack.c:58 print_circular_bug.constprop.0.cold+0x2d7/0x41e kernel/locking/lockdep.c:1258 check_prev_add kernel/locking/lockdep.c:1905 [inline] check_prevs_add kernel/locking/lockdep.c:2022 [inline] validate_chain kernel/locking/lockdep.c:2464 [inline] __lock_acquire+0x2e0e/0x3f20 kernel/locking/lockdep.c:3491 lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998 __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0xc4/0x1310 kernel/locking/mutex.c:893 perf_read_group kernel/events/core.c:4541 [inline] __perf_read kernel/events/core.c:4623 [inline] perf_read+0x2a2/0x7c0 kernel/events/core.c:4638 do_loop_readv_writev fs/read_write.c:695 [inline] do_loop_readv_writev fs/read_write.c:682 [inline] do_iter_read+0x3eb/0x5b0 fs/read_write.c:919 vfs_readv+0xc8/0x120 fs/read_write.c:981 do_readv+0xfc/0x2c0 fs/read_write.c:1014 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x45e179 RSP: 002b:00007fda87de8c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000013 RAX: ffffffffffffffda RBX: 0000000000026c00 RCX: 000000000045e179 RDX: 0000000000000008 RSI: 00000000200002c0 RDI: 0000000000000005 RBP: 000000000118cf80 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118cf4c R13: 00007ffec2683acf R14: 00007fda87de99c0 R15: 000000000118cf4c IPVS: ftp: loaded support on port[0] = 21 IPVS: ftp: loaded support on port[0] = 21 ptrace attach of "/root/syz-executor.5"[30267] was attempted by "/root/syz-executor.5"[30272] device vlan2 entered promiscuous mode ptrace attach of "/root/syz-executor.0"[30285] was attempted by "/root/syz-executor.0"[30289] device vlan2 entered promiscuous mode netlink: 8 bytes leftover after parsing attributes in process `syz-executor.4'. device vlan2 entered promiscuous mode netlink: 8 bytes leftover after parsing attributes in process `syz-executor.4'. netlink: 8 bytes leftover after parsing attributes in process `syz-executor.4'. netlink: 8 bytes leftover after parsing attributes in process `syz-executor.4'. netlink: 8 bytes leftover after parsing attributes in process `syz-executor.4'. netlink: 8 bytes leftover after parsing attributes in process `syz-executor.4'. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.5'. netlink: 8 bytes leftover after parsing attributes in process `syz-executor.4'. netlink: 124 bytes leftover after parsing attributes in process `syz-executor.4'. audit: type=1804 audit(1601332214.493:5397): pid=31289 uid=0 auid=0 ses=4 subj=system_u:system_r:kernel_t:s0 op="invalid_pcr" cause="open_writers" comm="syz-executor.5" name="/root/syzkaller-testdir833865280/syzkaller.lRyw9I/2123/bus" dev="sda1" ino=16404 res=1 audit: type=1804 audit(1601332214.513:5398): pid=31289 uid=0 auid=0 ses=4 subj=system_u:system_r:kernel_t:s0 op="invalid_pcr" cause="ToMToU" comm="syz-executor.5" name="/root/syzkaller-testdir833865280/syzkaller.lRyw9I/2123/bus" dev="sda1" ino=16404 res=1 netlink: 124 bytes leftover after parsing attributes in process `syz-executor.4'. audit: type=1804 audit(1601332214.723:5399): pid=31289 uid=0 auid=0 ses=4 subj=system_u:system_r:kernel_t:s0 op="invalid_pcr" cause="ToMToU" comm="syz-executor.5" name="/root/syzkaller-testdir833865280/syzkaller.lRyw9I/2123/bus" dev="sda1" ino=16404 res=1 audit: type=1804 audit(1601332214.753:5400): pid=31289 uid=0 auid=0 ses=4 subj=system_u:system_r:kernel_t:s0 op="invalid_pcr" cause="ToMToU" comm="syz-executor.5" name="/root/syzkaller-testdir833865280/syzkaller.lRyw9I/2123/bus" dev="sda1" ino=16404 res=1 audit: type=1804 audit(1601332215.153:5401): pid=31448 uid=0 auid=0 ses=4 subj=system_u:system_r:kernel_t:s0 op="invalid_pcr" cause="open_writers" comm="syz-executor.5" name="/root/syzkaller-testdir833865280/syzkaller.lRyw9I/2124/bus" dev="sda1" ino=16028 res=1 audit: type=1804 audit(1601332215.163:5402): pid=31448 uid=0 auid=0 ses=4 subj=system_u:system_r:kernel_t:s0 op="invalid_pcr" cause="ToMToU" comm="syz-executor.5" name="/root/syzkaller-testdir833865280/syzkaller.lRyw9I/2124/bus" dev="sda1" ino=16028 res=1 audit: type=1804 audit(1601332215.493:5403): pid=31547 uid=0 auid=0 ses=4 subj=system_u:system_r:kernel_t:s0 op="invalid_pcr" cause="open_writers" comm="syz-executor.5" name="/root/syzkaller-testdir833865280/syzkaller.lRyw9I/2125/bus" dev="sda1" ino=16757 res=1 audit: type=1804 audit(1601332215.503:5404): pid=31547 uid=0 auid=0 ses=4 subj=system_u:system_r:kernel_t:s0 op="invalid_pcr" cause="ToMToU" comm="syz-executor.5" name="/root/syzkaller-testdir833865280/syzkaller.lRyw9I/2125/bus" dev="sda1" ino=16757 res=1 audit: type=1804 audit(1601332216.023:5405): pid=31680 uid=0 auid=0 ses=4 subj=system_u:system_r:kernel_t:s0 op="invalid_pcr" cause="open_writers" comm="syz-executor.5" name="/root/syzkaller-testdir833865280/syzkaller.lRyw9I/2126/bus" dev="sda1" ino=16613 res=1 audit: type=1804 audit(1601332216.033:5406): pid=31680 uid=0 auid=0 ses=4 subj=system_u:system_r:kernel_t:s0 op="invalid_pcr" cause="ToMToU" comm="syz-executor.5" name="/root/syzkaller-testdir833865280/syzkaller.lRyw9I/2126/bus" dev="sda1" ino=16613 res=1 nla_parse: 11 callbacks suppressed netlink: 16 bytes leftover after parsing attributes in process `syz-executor.4'. bridge0: port 2(bridge_slave_1) entered disabled state bridge0: port 1(bridge_slave_0) entered disabled state batman_adv: batadv0: Interface deactivated: batadv_slave_0 batman_adv: batadv0: Interface deactivated: batadv_slave_1 ieee80211 phy30: mac80211_hwsim_configure_filter ieee80211 phy30: mac80211_hwsim_bss_info_changed(changed=0xa00 vif->addr=02:00:00:00:1e:00) ieee80211 phy30: BCN EN: 0 (BI=100) ieee80211 phy30: beaconing vifs remaining: 0