====================================================== WARNING: possible circular locking dependency detected 6.13.0-rc1-syzkaller-00316-gb5f217084ab3 #0 Not tainted ------------------------------------------------------ udevd/5203 is trying to acquire lock: ffff888011a82140 (&htab->lockdep_key#61){..-.}-{2:2}, at: htab_lock_bucket+0x1a4/0x370 kernel/bpf/hashtab.c:167 but task is already holding lock: ffff888011a802a8 (&htab->lockdep_key#59){..-.}-{2:2}, at: htab_lock_bucket+0x1a4/0x370 kernel/bpf/hashtab.c:167 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&htab->lockdep_key#59){..-.}-{2:2}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 htab_lock_bucket+0x1a4/0x370 kernel/bpf/hashtab.c:167 htab_lru_map_delete_elem+0x1f1/0x700 kernel/bpf/hashtab.c:1484 bpf_prog_6f5f05285f674219+0x43/0x4c bpf_dispatcher_nop_func include/linux/bpf.h:1290 [inline] __bpf_prog_run include/linux/filter.h:701 [inline] bpf_prog_run include/linux/filter.h:708 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2351 [inline] bpf_trace_run2+0x2ec/0x540 kernel/trace/bpf_trace.c:2392 __traceiter_contention_begin+0x7b/0xb0 include/trace/events/lock.h:95 trace_contention_begin+0x11b/0x140 include/trace/events/lock.h:95 __pv_queued_spin_lock_slowpath+0x114/0xdb0 kernel/locking/qspinlock.c:402 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 htab_lock_bucket+0x1a4/0x370 kernel/bpf/hashtab.c:167 htab_lru_map_delete_elem+0x1f1/0x700 kernel/bpf/hashtab.c:1484 bpf_prog_6f5f05285f674219+0x43/0x4c bpf_dispatcher_nop_func include/linux/bpf.h:1290 [inline] __bpf_prog_run include/linux/filter.h:701 [inline] bpf_prog_run include/linux/filter.h:708 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2351 [inline] bpf_trace_run2+0x2ec/0x540 kernel/trace/bpf_trace.c:2392 __traceiter_contention_begin+0x7b/0xb0 include/trace/events/lock.h:95 trace_contention_begin+0xf9/0x120 include/trace/events/lock.h:95 __mutex_lock_common kernel/locking/mutex.c:587 [inline] __mutex_lock+0x1bd/0xee0 kernel/locking/mutex.c:735 fdget_pos+0x254/0x320 fs/file.c:1191 class_fd_pos_constructor include/linux/file.h:85 [inline] __do_sys_getdents64 fs/readdir.c:392 [inline] __se_sys_getdents64+0x94/0x4b0 fs/readdir.c:389 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (&htab->lockdep_key#61){..-.}-{2:2}: check_prev_add kernel/locking/lockdep.c:3161 [inline] check_prevs_add kernel/locking/lockdep.c:3280 [inline] validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904 __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5226 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 htab_lock_bucket+0x1a4/0x370 kernel/bpf/hashtab.c:167 htab_lru_map_delete_elem+0x1f1/0x700 kernel/bpf/hashtab.c:1484 bpf_prog_6f5f05285f674219+0x43/0x4c bpf_dispatcher_nop_func include/linux/bpf.h:1290 [inline] __bpf_prog_run include/linux/filter.h:701 [inline] bpf_prog_run include/linux/filter.h:708 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2351 [inline] bpf_trace_run2+0x2ec/0x540 kernel/trace/bpf_trace.c:2392 __traceiter_contention_begin+0x7b/0xb0 include/trace/events/lock.h:95 trace_contention_begin+0x11b/0x140 include/trace/events/lock.h:95 __pv_queued_spin_lock_slowpath+0x114/0xdb0 kernel/locking/qspinlock.c:402 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 htab_lock_bucket+0x1a4/0x370 kernel/bpf/hashtab.c:167 htab_lru_map_delete_elem+0x1f1/0x700 kernel/bpf/hashtab.c:1484 bpf_prog_6f5f05285f674219+0x43/0x4c bpf_dispatcher_nop_func include/linux/bpf.h:1290 [inline] __bpf_prog_run include/linux/filter.h:701 [inline] bpf_prog_run include/linux/filter.h:708 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2351 [inline] bpf_trace_run2+0x2ec/0x540 kernel/trace/bpf_trace.c:2392 __traceiter_contention_begin+0x7b/0xb0 include/trace/events/lock.h:95 trace_contention_begin+0xf9/0x120 include/trace/events/lock.h:95 __mutex_lock_common kernel/locking/mutex.c:587 [inline] __mutex_lock+0x1bd/0xee0 kernel/locking/mutex.c:735 kernfs_seq_start+0x53/0x3b0 fs/kernfs/file.c:154 seq_read_iter+0x3cc/0xd70 fs/seq_file.c:225 new_sync_read fs/read_write.c:484 [inline] vfs_read+0x991/0xb70 fs/read_write.c:565 ksys_read+0x18f/0x2b0 fs/read_write.c:708 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&htab->lockdep_key#59); lock(&htab->lockdep_key#61); lock(&htab->lockdep_key#59); lock(&htab->lockdep_key#61); *** DEADLOCK *** 5 locks held by udevd/5203: #0: ffff888061e40e80 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb4/0xd70 fs/seq_file.c:182 #1: ffff888035363c88 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x53/0x3b0 fs/kernfs/file.c:154 #2: ffffffff8e937aa0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #2: ffffffff8e937aa0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #2: ffffffff8e937aa0 (rcu_read_lock){....}-{1:3}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2350 [inline] #2: ffffffff8e937aa0 (rcu_read_lock){....}-{1:3}, at: bpf_trace_run2+0x1fc/0x540 kernel/trace/bpf_trace.c:2392 #3: ffff888011a802a8 (&htab->lockdep_key#59){..-.}-{2:2}, at: htab_lock_bucket+0x1a4/0x370 kernel/bpf/hashtab.c:167 #4: ffffffff8e937aa0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #4: ffffffff8e937aa0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #4: ffffffff8e937aa0 (rcu_read_lock){....}-{1:3}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2350 [inline] #4: ffffffff8e937aa0 (rcu_read_lock){....}-{1:3}, at: bpf_trace_run2+0x1fc/0x540 kernel/trace/bpf_trace.c:2392 stack backtrace: CPU: 1 UID: 0 PID: 5203 Comm: udevd Not tainted 6.13.0-rc1-syzkaller-00316-gb5f217084ab3 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_circular_bug+0x13a/0x1b0 kernel/locking/lockdep.c:2074 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2206 check_prev_add kernel/locking/lockdep.c:3161 [inline] check_prevs_add kernel/locking/lockdep.c:3280 [inline] validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904 __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5226 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 htab_lock_bucket+0x1a4/0x370 kernel/bpf/hashtab.c:167 htab_lru_map_delete_elem+0x1f1/0x700 kernel/bpf/hashtab.c:1484 bpf_prog_6f5f05285f674219+0x43/0x4c bpf_dispatcher_nop_func include/linux/bpf.h:1290 [inline] __bpf_prog_run include/linux/filter.h:701 [inline] bpf_prog_run include/linux/filter.h:708 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2351 [inline] bpf_trace_run2+0x2ec/0x540 kernel/trace/bpf_trace.c:2392 __traceiter_contention_begin+0x7b/0xb0 include/trace/events/lock.h:95 trace_contention_begin+0x11b/0x140 include/trace/events/lock.h:95 __pv_queued_spin_lock_slowpath+0x114/0xdb0 kernel/locking/qspinlock.c:402 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 htab_lock_bucket+0x1a4/0x370 kernel/bpf/hashtab.c:167 htab_lru_map_delete_elem+0x1f1/0x700 kernel/bpf/hashtab.c:1484 bpf_prog_6f5f05285f674219+0x43/0x4c bpf_dispatcher_nop_func include/linux/bpf.h:1290 [inline] __bpf_prog_run include/linux/filter.h:701 [inline] bpf_prog_run include/linux/filter.h:708 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2351 [inline] bpf_trace_run2+0x2ec/0x540 kernel/trace/bpf_trace.c:2392 __traceiter_contention_begin+0x7b/0xb0 include/trace/events/lock.h:95 trace_contention_begin+0xf9/0x120 include/trace/events/lock.h:95 __mutex_lock_common kernel/locking/mutex.c:587 [inline] __mutex_lock+0x1bd/0xee0 kernel/locking/mutex.c:735 kernfs_seq_start+0x53/0x3b0 fs/kernfs/file.c:154 seq_read_iter+0x3cc/0xd70 fs/seq_file.c:225 new_sync_read fs/read_write.c:484 [inline] vfs_read+0x991/0xb70 fs/read_write.c:565 ksys_read+0x18f/0x2b0 fs/read_write.c:708 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4f1f916b6a Code: 00 3d 00 00 41 00 75 0d 50 48 8d 3d 2d 08 0a 00 e8 ea 7d 01 00 31 c0 e9 07 ff ff ff 64 8b 04 25 18 00 00 00 85 c0 75 1b 0f 05 <48> 3d 00 f0 ff ff 76 6c 48 8b 15 8f a2 0d 00 f7 d8 64 89 02 48 83 RSP: 002b:00007ffd76681df8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 000055ff1945f130 RCX: 00007f4f1f916b6a RDX: 0000000000001000 RSI: 000055ff19423620 RDI: 000000000000000c RBP: 000055ff1945f130 R08: 000000000000000c R09: 0000000000000000 R10: 0000000000000010 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000003fff R14: 00007ffd766822d8 R15: 000000000000000a