============================================ WARNING: possible recursive locking detected 6.1.33-syzkaller #0 Not tainted -------------------------------------------- syz-executor.1/3575 is trying to acquire lock: ffffffff8cf84fd8 (trace_printk_lock){-.-.}-{2:2}, at: ____bpf_trace_printk kernel/trace/bpf_trace.c:390 [inline] ffffffff8cf84fd8 (trace_printk_lock){-.-.}-{2:2}, at: bpf_trace_printk+0x151/0x200 kernel/trace/bpf_trace.c:376 but task is already holding lock: ffffffff8cf84fd8 (trace_printk_lock){-.-.}-{2:2}, at: ____bpf_trace_printk kernel/trace/bpf_trace.c:390 [inline] ffffffff8cf84fd8 (trace_printk_lock){-.-.}-{2:2}, at: bpf_trace_printk+0x151/0x200 kernel/trace/bpf_trace.c:376 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.1/3575: #0: ffff8880288b4308 (&xt[i].mutex){+.+.}-{3:3}, at: xt_find_table_lock+0x48/0x3a0 net/netfilter/x_tables.c:1242 #1: ffff8880288b42c0 (&lock->wait_lock){+.+.}-{2:2}, at: __mutex_lock_common+0x11bc/0x2520 kernel/locking/mutex.c:701 #2: ffffffff8cf272a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:305 #3: ffffffff8cf84fd8 (trace_printk_lock){-.-.}-{2:2}, at: ____bpf_trace_printk kernel/trace/bpf_trace.c:390 [inline] #3: ffffffff8cf84fd8 (trace_printk_lock){-.-.}-{2:2}, at: bpf_trace_printk+0x151/0x200 kernel/trace/bpf_trace.c:376 #4: ffffffff8cf272a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:305 stack backtrace: CPU: 0 PID: 3575 Comm: syz-executor.1 Not tainted 6.1.33-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 print_deadlock_bug kernel/locking/lockdep.c:2991 [inline] check_deadlock kernel/locking/lockdep.c:3034 [inline] validate_chain+0x4726/0x58e0 kernel/locking/lockdep.c:3819 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5056 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5669 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 ____bpf_trace_printk kernel/trace/bpf_trace.c:390 [inline] bpf_trace_printk+0x151/0x200 kernel/trace/bpf_trace.c:376 bpf_prog_0605f9f479290f07+0x2f/0x33 bpf_dispatcher_nop_func include/linux/bpf.h:975 [inline] __bpf_prog_run include/linux/filter.h:600 [inline] bpf_prog_run include/linux/filter.h:607 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2258 [inline] bpf_trace_run2+0x1d6/0x3e0 kernel/trace/bpf_trace.c:2297 __traceiter_contention_end+0x74/0xa0 include/trace/events/lock.h:122 trace_contention_end+0x14c/0x190 include/trace/events/lock.h:122 __pv_queued_spin_lock_slowpath+0x935/0xc50 kernel/locking/qspinlock.c:560 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:591 [inline] queued_spin_lock_slowpath+0x42/0x50 arch/x86/include/asm/qspinlock.h:51 queued_spin_lock include/asm-generic/qspinlock.h:114 [inline] do_raw_spin_lock+0x269/0x370 kernel/locking/spinlock_debug.c:115 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline] _raw_spin_lock_irqsave+0xdd/0x120 kernel/locking/spinlock.c:162 ____bpf_trace_printk kernel/trace/bpf_trace.c:390 [inline] bpf_trace_printk+0x151/0x200 kernel/trace/bpf_trace.c:376 bpf_prog_0605f9f479290f07+0x2f/0x33 bpf_dispatcher_nop_func include/linux/bpf.h:975 [inline] __bpf_prog_run include/linux/filter.h:600 [inline] bpf_prog_run include/linux/filter.h:607 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2258 [inline] bpf_trace_run2+0x1d6/0x3e0 kernel/trace/bpf_trace.c:2297 __traceiter_contention_end+0x74/0xa0 include/trace/events/lock.h:122 trace_contention_end+0x12f/0x170 include/trace/events/lock.h:122 __mutex_lock_common+0x13a1/0x2520 kernel/locking/mutex.c:722 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:799 xt_find_table_lock+0x48/0x3a0 net/netfilter/x_tables.c:1242 xt_request_find_table_lock+0x22/0xf0 net/netfilter/x_tables.c:1284 get_info net/ipv4/netfilter/ip_tables.c:965 [inline] do_ipt_get_ctl+0x872/0x1890 net/ipv4/netfilter/ip_tables.c:1653 nf_getsockopt+0x28e/0x2b0 net/netfilter/nf_sockopt.c:116 ip_getsockopt+0x21a/0x2d0 net/ipv4/ip_sockglue.c:1824 tcp_getsockopt+0x15c/0x1c0 net/ipv4/tcp.c:4403 __sys_getsockopt+0x2b2/0x5d0 net/socket.c:2296 __do_sys_getsockopt net/socket.c:2311 [inline] __se_sys_getsockopt net/socket.c:2308 [inline] __x64_sys_getsockopt+0xb1/0xc0 net/socket.c:2308 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7fd771c8d78a Code: 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 49 89 ca b8 37 00 00 00 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:00007ffe02e50f48 EFLAGS: 00000246 ORIG_RAX: 0000000000000037 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fd771c8d78a RDX: 0000000000000040 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00007ffe02e50f70 R08: 00007ffe02e50f6c R09: ffffffffff000000 R10: 00007ffe02e50f70 R11: 0000000000000246 R12: 0000000000000032 R13: 0000000000000003 R14: 00007ffe02e50f6c R15: 00007fd771d86d20