============================================ WARNING: possible recursive locking detected 6.0.0-syzkaller #0 Not tainted -------------------------------------------- syz-executor.3/12319 is trying to acquire lock: ffffffff8c00eb78 (trace_printk_lock){....}-{2:2}, at: ____bpf_trace_printk kernel/trace/bpf_trace.c:388 [inline] ffffffff8c00eb78 (trace_printk_lock){....}-{2:2}, at: bpf_trace_printk+0xcf/0x170 kernel/trace/bpf_trace.c:374 but task is already holding lock: ffffffff8c00eb78 (trace_printk_lock){....}-{2:2}, at: ____bpf_trace_printk kernel/trace/bpf_trace.c:388 [inline] ffffffff8c00eb78 (trace_printk_lock){....}-{2:2}, at: bpf_trace_printk+0xcf/0x170 kernel/trace/bpf_trace.c:374 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(trace_printk_lock); lock(trace_printk_lock); *** DEADLOCK *** May be due to missing lock nesting notation 5 locks held by syz-executor.3/12319: #0: ffff88807dda04d8 (&runtime->oss.params_lock){+.+.}-{3:3}, at: snd_pcm_oss_change_params sound/core/oss/pcm_oss.c:1113 [inline] #0: ffff88807dda04d8 (&runtime->oss.params_lock){+.+.}-{3:3}, at: snd_pcm_oss_make_ready+0xc7/0x1b0 sound/core/oss/pcm_oss.c:1175 #1: ffff88807dda0230 (&runtime->buffer_mutex){+.+.}-{3:3}, at: snd_pcm_buffer_access_lock+0x9e/0xd0 sound/core/pcm_native.c:695 #2: ffffffff8bf86c00 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x0/0x340 kernel/trace/./bpf_trace.h:11 #3: ffffffff8c00eb78 (trace_printk_lock){....}-{2:2}, at: ____bpf_trace_printk kernel/trace/bpf_trace.c:388 [inline] #3: ffffffff8c00eb78 (trace_printk_lock){....}-{2:2}, at: bpf_trace_printk+0xcf/0x170 kernel/trace/bpf_trace.c:374 #4: ffffffff8bf86c00 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x0/0x340 kernel/trace/./bpf_trace.h:11 stack backtrace: CPU: 1 PID: 12319 Comm: syz-executor.3 Not tainted 6.0.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/22/2022 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_deadlock_bug kernel/locking/lockdep.c:2988 [inline] check_deadlock kernel/locking/lockdep.c:3031 [inline] validate_chain kernel/locking/lockdep.c:3816 [inline] __lock_acquire.cold+0x116/0x3a7 kernel/locking/lockdep.c:5053 lock_acquire kernel/locking/lockdep.c:5666 [inline] lock_acquire+0x1ab/0x570 kernel/locking/lockdep.c:5631 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:162 ____bpf_trace_printk kernel/trace/bpf_trace.c:388 [inline] bpf_trace_printk+0xcf/0x170 kernel/trace/bpf_trace.c:374 ___bpf_prog_run+0x369d/0x7960 kernel/bpf/core.c:1813 __bpf_prog_run32+0x8a/0xd0 kernel/bpf/core.c:2036 bpf_dispatcher_nop_func include/linux/bpf.h:903 [inline] __bpf_prog_run include/linux/filter.h:594 [inline] bpf_prog_run include/linux/filter.h:601 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2046 [inline] bpf_trace_run2+0x110/0x340 kernel/trace/bpf_trace.c:2083 __bpf_trace_contention_begin+0xb5/0xf0 include/trace/events/lock.h:95 trace_contention_begin.constprop.0+0xda/0x1b0 include/trace/events/lock.h:95 __pv_queued_spin_lock_slowpath+0x103/0xb50 kernel/locking/qspinlock.c:405 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:591 [inline] queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline] queued_spin_lock include/asm-generic/qspinlock.h:114 [inline] do_raw_spin_lock+0x200/0x2a0 kernel/locking/spinlock_debug.c:115 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline] _raw_spin_lock_irqsave+0x41/0x50 kernel/locking/spinlock.c:162 ____bpf_trace_printk kernel/trace/bpf_trace.c:388 [inline] bpf_trace_printk+0xcf/0x170 kernel/trace/bpf_trace.c:374 ___bpf_prog_run+0x369d/0x7960 kernel/bpf/core.c:1813 __bpf_prog_run32+0x8a/0xd0 kernel/bpf/core.c:2036 bpf_dispatcher_nop_func include/linux/bpf.h:903 [inline] __bpf_prog_run include/linux/filter.h:594 [inline] bpf_prog_run include/linux/filter.h:601 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2046 [inline] bpf_trace_run2+0x110/0x340 kernel/trace/bpf_trace.c:2083 __bpf_trace_contention_begin+0xb5/0xf0 include/trace/events/lock.h:95 trace_contention_begin+0xc0/0x150 include/trace/events/lock.h:95 __mutex_lock_common kernel/locking/mutex.c:605 [inline] __mutex_lock+0x13c/0x1350 kernel/locking/mutex.c:747 snd_pcm_buffer_access_lock+0x9e/0xd0 sound/core/pcm_native.c:695 snd_pcm_hw_params+0xbb/0x19f0 sound/core/pcm_native.c:723 snd_pcm_kernel_ioctl+0x164/0x310 sound/core/pcm_native.c:3437 snd_pcm_oss_change_params_locked+0x14dd/0x3a60 sound/core/oss/pcm_oss.c:976 snd_pcm_oss_change_params sound/core/oss/pcm_oss.c:1116 [inline] snd_pcm_oss_make_ready+0xe7/0x1b0 sound/core/oss/pcm_oss.c:1175 snd_pcm_oss_set_trigger.isra.0+0x30f/0x6e0 sound/core/oss/pcm_oss.c:2092 snd_pcm_oss_poll+0x661/0xb10 sound/core/oss/pcm_oss.c:2878 vfs_poll include/linux/poll.h:88 [inline] do_pollfd fs/select.c:873 [inline] do_poll fs/select.c:921 [inline] do_sys_poll+0x61c/0xea0 fs/select.c:1015 __do_sys_poll fs/select.c:1080 [inline] __se_sys_poll fs/select.c:1068 [inline] __x64_sys_poll+0x18c/0x480 fs/select.c:1068 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+0x63/0xcd RIP: 0033:0x7fcb40e8a5a9 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 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fcb41f0c168 EFLAGS: 00000246 ORIG_RAX: 0000000000000007 RAX: ffffffffffffffda RBX: 00007fcb40fabf80 RCX: 00007fcb40e8a5a9 RDX: 0000000000000242 RSI: 20000000000000e6 RDI: 0000000020000140 RBP: 00007fcb40ee5580 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd7917ff0f R14: 00007fcb41f0c300 R15: 0000000000022000