============================================ WARNING: possible recursive locking detected 5.19.0-rc7-syzkaller-00199-g515f71412bb7 #0 Not tainted -------------------------------------------- syz-executor.1/7749 is trying to acquire lock: ffffffff8be0b4b8 (trace_printk_lock){..-.}-{2:2}, at: ____bpf_trace_printk kernel/trace/bpf_trace.c:388 [inline] ffffffff8be0b4b8 (trace_printk_lock){..-.}-{2:2}, at: bpf_trace_printk+0xcf/0x170 kernel/trace/bpf_trace.c:374 but task is already holding lock: ffffffff8be0b4b8 (trace_printk_lock){..-.}-{2:2}, at: ____bpf_trace_printk kernel/trace/bpf_trace.c:388 [inline] ffffffff8be0b4b8 (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.1/7749: #0: ffffffff8bdc9a70 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: copy_process+0x43c1/0x7020 kernel/fork.c:2344 #1: ffffffff8bdd4728 (freezer_mutex){+.+.}-{3:3}, at: freezer_fork kernel/cgroup/legacy_freezer.c:217 [inline] #1: ffffffff8bdd4728 (freezer_mutex){+.+.}-{3:3}, at: freezer_fork+0xbd/0x490 kernel/cgroup/legacy_freezer.c:203 #2: ffffffff8bd84620 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x0/0x340 kernel/trace/./bpf_trace.h:11 #3: ffffffff8be0b4b8 (trace_printk_lock){..-.}-{2:2}, at: ____bpf_trace_printk kernel/trace/bpf_trace.c:388 [inline] #3: ffffffff8be0b4b8 (trace_printk_lock){..-.}-{2:2}, at: bpf_trace_printk+0xcf/0x170 kernel/trace/bpf_trace.c:374 #4: ffffffff8bd84620 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x0/0x340 kernel/trace/./bpf_trace.h:11 stack backtrace: CPU: 1 PID: 7749 Comm: syz-executor.1 Not tainted 5.19.0-rc7-syzkaller-00199-g515f71412bb7 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022 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+0x1f5/0x3b4 kernel/locking/lockdep.c:5053 lock_acquire kernel/locking/lockdep.c:5665 [inline] lock_acquire+0x1ab/0x570 kernel/locking/lockdep.c:5630 __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:1852 __bpf_prog_run32+0x8a/0xd0 kernel/bpf/core.c:2075 bpf_dispatcher_nop_func include/linux/bpf.h:869 [inline] __bpf_prog_run include/linux/filter.h:628 [inline] bpf_prog_run include/linux/filter.h:635 [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_end+0xb5/0xf0 include/trace/events/lock.h:122 trace_contention_end.constprop.0+0xd7/0x1b0 include/trace/events/lock.h:122 __pv_queued_spin_lock_slowpath+0x258/0xb50 kernel/locking/qspinlock.c:560 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:1852 __bpf_prog_run32+0x8a/0xd0 kernel/bpf/core.c:2075 bpf_dispatcher_nop_func include/linux/bpf.h:869 [inline] __bpf_prog_run include/linux/filter.h:628 [inline] bpf_prog_run include/linux/filter.h:635 [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_end+0xb5/0xf0 include/trace/events/lock.h:122 trace_contention_end+0xc0/0x150 include/trace/events/lock.h:122 __mutex_lock_common kernel/locking/mutex.c:612 [inline] __mutex_lock+0x227/0x1350 kernel/locking/mutex.c:747 freezer_fork kernel/cgroup/legacy_freezer.c:217 [inline] freezer_fork+0xbd/0x490 kernel/cgroup/legacy_freezer.c:203 cgroup_post_fork+0x2e6/0x8f0 kernel/cgroup/cgroup.c:6389 copy_process+0x53aa/0x7020 kernel/fork.c:2469 kernel_clone+0xe7/0xab0 kernel/fork.c:2655 __do_sys_clone+0xba/0x100 kernel/fork.c:2789 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: 0033:0x7f60cd88a631 Code: 48 85 ff 74 3d 48 85 f6 74 38 48 83 ee 10 48 89 4e 08 48 89 3e 48 89 d7 4c 89 c2 4d 89 c8 4c 8b 54 24 08 b8 38 00 00 00 0f 05 <48> 85 c0 7c 13 74 01 c3 31 ed 58 5f ff d0 48 89 c7 b8 3c 00 00 00 RSP: 002b:00007ffd061fdb08 EFLAGS: 00000206 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007f60cea19700 RCX: 00007f60cd88a631 RDX: 00007f60cea199d0 RSI: 00007f60cea192f0 RDI: 00000000003d0f00 RBP: 00007ffd061fdd50 R08: 00007f60cea19700 R09: 00007f60cea19700 R10: 00007f60cea199d0 R11: 0000000000000206 R12: 00007ffd061fdbbe R13: 00007ffd061fdbbf R14: 00007f60cea19300 R15: 0000000000022000