====================================================== WARNING: possible circular locking dependency detected 5.15.0-rc5-next-20211018-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.4/13609 is trying to acquire lock: ffff88802b186a28 (&mm->mmap_lock#2){++++}-{3:3}, at: __might_fault+0xa1/0x170 mm/memory.c:5243 but task is already holding lock: ffff8880b9c3fab0 (&cpuctx_mutex){+.+.}-{3:3}, at: perf_event_ctx_lock_nested+0x23a/0x490 kernel/events/core.c:1357 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&cpuctx_mutex){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:599 [inline] __mutex_lock+0x12f/0x12f0 kernel/locking/mutex.c:732 perf_event_init_cpu+0x172/0x3e0 kernel/events/core.c:13325 perf_event_init+0x39d/0x408 kernel/events/core.c:13372 start_kernel+0x2bb/0x49b init/main.c:1063 secondary_startup_64_no_verify+0xb0/0xbb -> #2 (pmus_lock){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:599 [inline] __mutex_lock+0x12f/0x12f0 kernel/locking/mutex.c:732 perf_event_init_cpu+0xc4/0x3e0 kernel/events/core.c:13319 cpuhp_invoke_callback+0x3b5/0x9a0 kernel/cpu.c:190 cpuhp_invoke_callback_range kernel/cpu.c:665 [inline] cpuhp_up_callbacks kernel/cpu.c:693 [inline] _cpu_up+0x3b0/0x790 kernel/cpu.c:1368 cpu_up kernel/cpu.c:1404 [inline] cpu_up+0xfe/0x1a0 kernel/cpu.c:1376 bringup_nonboot_cpus+0xfe/0x130 kernel/cpu.c:1470 smp_init+0x2e/0x145 kernel/smp.c:1092 kernel_init_freeable+0x477/0x73a init/main.c:1618 kernel_init+0x1a/0x1d0 init/main.c:1515 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 -> #1 (cpu_hotplug_lock){++++}-{0:0}: percpu_down_read include/linux/percpu-rwsem.h:51 [inline] cpus_read_lock+0x3e/0x140 kernel/cpu.c:308 wake_up_all_idle_cpus+0x13/0x80 kernel/smp.c:1173 cpu_latency_qos_apply kernel/power/qos.c:249 [inline] cpu_latency_qos_remove_request.part.0+0xc4/0x2f0 kernel/power/qos.c:328 cpu_latency_qos_remove_request+0x65/0x80 kernel/power/qos.c:330 snd_pcm_hw_params+0x1481/0x1990 sound/core/pcm_native.c:784 snd_pcm_kernel_ioctl+0x164/0x310 sound/core/pcm_native.c:3355 snd_pcm_oss_change_params_locked+0x1936/0x3a60 sound/core/oss/pcm_oss.c:947 snd_pcm_oss_change_params sound/core/oss/pcm_oss.c:1091 [inline] snd_pcm_oss_mmap+0x442/0x550 sound/core/oss/pcm_oss.c:2910 call_mmap include/linux/fs.h:2164 [inline] mmap_region+0xd8c/0x1650 mm/mmap.c:1787 do_mmap+0x869/0xfb0 mm/mmap.c:1575 vm_mmap_pgoff+0x1b7/0x290 mm/util.c:519 ksys_mmap_pgoff+0x49f/0x620 mm/mmap.c:1624 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae -> #0 (&mm->mmap_lock#2){++++}-{3:3}: check_prev_add kernel/locking/lockdep.c:3063 [inline] check_prevs_add kernel/locking/lockdep.c:3186 [inline] validate_chain kernel/locking/lockdep.c:3801 [inline] __lock_acquire+0x2a07/0x54a0 kernel/locking/lockdep.c:5027 lock_acquire kernel/locking/lockdep.c:5637 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5602 __might_fault mm/memory.c:5244 [inline] __might_fault+0x104/0x170 mm/memory.c:5229 _copy_to_user+0x27/0x150 lib/usercopy.c:28 copy_to_user include/linux/uaccess.h:200 [inline] perf_read_group kernel/events/core.c:5329 [inline] __perf_read kernel/events/core.c:5396 [inline] perf_read+0x736/0x900 kernel/events/core.c:5415 do_loop_readv_writev fs/read_write.c:750 [inline] do_loop_readv_writev fs/read_write.c:737 [inline] do_iter_read+0x501/0x760 fs/read_write.c:792 vfs_readv+0xe5/0x150 fs/read_write.c:910 do_readv+0x139/0x300 fs/read_write.c:947 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae other info that might help us debug this: Chain exists of: &mm->mmap_lock#2 --> pmus_lock --> &cpuctx_mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&cpuctx_mutex); lock(pmus_lock); lock(&cpuctx_mutex); lock(&mm->mmap_lock#2); *** DEADLOCK *** 1 lock held by syz-executor.4/13609: #0: ffff8880b9c3fab0 (&cpuctx_mutex){+.+.}-{3:3}, at: perf_event_ctx_lock_nested+0x23a/0x490 kernel/events/core.c:1357 stack backtrace: CPU: 1 PID: 13609 Comm: syz-executor.4 Not tainted 5.15.0-rc5-next-20211018-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 check_noncircular+0x25f/0x2e0 kernel/locking/lockdep.c:2143 check_prev_add kernel/locking/lockdep.c:3063 [inline] check_prevs_add kernel/locking/lockdep.c:3186 [inline] validate_chain kernel/locking/lockdep.c:3801 [inline] __lock_acquire+0x2a07/0x54a0 kernel/locking/lockdep.c:5027 lock_acquire kernel/locking/lockdep.c:5637 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5602 __might_fault mm/memory.c:5244 [inline] __might_fault+0x104/0x170 mm/memory.c:5229 _copy_to_user+0x27/0x150 lib/usercopy.c:28 copy_to_user include/linux/uaccess.h:200 [inline] perf_read_group kernel/events/core.c:5329 [inline] __perf_read kernel/events/core.c:5396 [inline] perf_read+0x736/0x900 kernel/events/core.c:5415 do_loop_readv_writev fs/read_write.c:750 [inline] do_loop_readv_writev fs/read_write.c:737 [inline] do_iter_read+0x501/0x760 fs/read_write.c:792 vfs_readv+0xe5/0x150 fs/read_write.c:910 do_readv+0x139/0x300 fs/read_write.c:947 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fc690ae0a39 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fc68e056188 EFLAGS: 00000246 ORIG_RAX: 0000000000000013 RAX: ffffffffffffffda RBX: 00007fc690be3f60 RCX: 00007fc690ae0a39 RDX: 0000000000000001 RSI: 00000000200002c0 RDI: 0000000000000007 RBP: 00007fc690b3ac5f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fff75bcd39f R14: 00007fc68e056300 R15: 0000000000022000