============================================ WARNING: possible recursive locking detected 6.8.0-syzkaller-05271-gf99c5f563c17 #0 Not tainted -------------------------------------------- syz-executor796/5112 is trying to acquire lock: ffff888021ad39f8 (&trie->lock){..-.}-{2:2}, at: trie_delete_elem+0x96/0x6a0 kernel/bpf/lpm_trie.c:451 but task is already holding lock: ffff88802cdcc9f8 (&trie->lock){..-.}-{2:2}, at: trie_delete_elem+0x96/0x6a0 kernel/bpf/lpm_trie.c:451 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&trie->lock); lock(&trie->lock); *** DEADLOCK *** May be due to missing lock nesting notation 5 locks held by syz-executor796/5112: #0: ffff88802f320420 (sb_writers#3){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2853 [inline] #0: ffff88802f320420 (sb_writers#3){.+.+}-{0:0}, at: vfs_write+0x233/0xcb0 fs/read_write.c:586 #1: ffffffff8e1e2608 (oom_adj_mutex){+.+.}-{3:3}, at: __set_oom_adj+0x88/0xc60 fs/proc/base.c:1071 #2: ffffffff8e131920 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #2: ffffffff8e131920 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #2: ffffffff8e131920 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2380 [inline] #2: ffffffff8e131920 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x114/0x420 kernel/trace/bpf_trace.c:2420 #3: ffff88802cdcc9f8 (&trie->lock){..-.}-{2:2}, at: trie_delete_elem+0x96/0x6a0 kernel/bpf/lpm_trie.c:451 #4: ffffffff8e131920 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #4: ffffffff8e131920 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #4: ffffffff8e131920 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2380 [inline] #4: ffffffff8e131920 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x114/0x420 kernel/trace/bpf_trace.c:2420 stack backtrace: CPU: 1 PID: 5112 Comm: syz-executor796 Not tainted 6.8.0-syzkaller-05271-gf99c5f563c17 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e7/0x2e0 lib/dump_stack.c:106 check_deadlock kernel/locking/lockdep.c:3062 [inline] validate_chain+0x15c1/0x58e0 kernel/locking/lockdep.c:3856 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137 lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 trie_delete_elem+0x96/0x6a0 kernel/bpf/lpm_trie.c:451 bpf_prog_57115342e4867123+0x47/0x4b bpf_dispatcher_nop_func include/linux/bpf.h:1234 [inline] __bpf_prog_run include/linux/filter.h:657 [inline] bpf_prog_run include/linux/filter.h:664 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2381 [inline] bpf_trace_run2+0x204/0x420 kernel/trace/bpf_trace.c:2420 __traceiter_contention_begin+0x7b/0xb0 include/trace/events/lock.h:95 trace_contention_begin+0xf9/0x120 include/trace/events/lock.h:95 __pv_queued_spin_lock_slowpath+0x115/0xc60 kernel/locking/qspinlock.c:405 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:584 [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+0x272/0x370 kernel/locking/spinlock_debug.c:116 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline] _raw_spin_lock_irqsave+0xe1/0x120 kernel/locking/spinlock.c:162 trie_delete_elem+0x96/0x6a0 kernel/bpf/lpm_trie.c:451 bpf_prog_57115342e4867123+0x47/0x4b bpf_dispatcher_nop_func include/linux/bpf.h:1234 [inline] __bpf_prog_run include/linux/filter.h:657 [inline] bpf_prog_run include/linux/filter.h:664 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2381 [inline] bpf_trace_run2+0x204/0x420 kernel/trace/bpf_trace.c:2420 __traceiter_contention_begin+0x7b/0xb0 include/trace/events/lock.h:95 trace_contention_begin+0xd7/0x100 include/trace/events/lock.h:95 __mutex_lock_common kernel/locking/mutex.c:610 [inline] __mutex_lock+0x147/0xd70 kernel/locking/mutex.c:752 __set_oom_adj+0x88/0xc60 fs/proc/base.c:1071 oom_score_adj_write+0x1a9/0x260 fs/proc/base.c:1236 vfs_write+0x2a4/0xcb0 fs/read_write.c:588 ksys_write+0x1a0/0x2c0 fs/read_write.c:643 do_syscall_64+0xfb/0x240 entry_SYSCALL_64_after_hwframe+0x6d/0x75 RIP: 0033:0x7fde99b4e0a0 Code: 40 00 48 c7 c2 b8 ff ff ff f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 80 3d e1 8f 07 00 00 74 17 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 58 c3 0f 1f 80 00 00 00 00 48 83 ec 28 48 89 RSP: 002b:00007fff8d048998 EFLAGS: 00000202 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007fde99b4e0a0 RDX: 0000000000000004 RSI: 00007fff8d0489c0 RDI: 0000000000000003 RBP: 0000000000000004 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 00007fff8d0489c0 R13: 00007fff8d048e9c R14: 00007fff8d048eb0 R15: 00007fff8d048ea0