====================================================== WARNING: possible circular locking dependency detected 6.10.0-syzkaller-12690-gfdf1c728fac5 #0 Not tainted ------------------------------------------------------ syz.4.306/6866 is trying to acquire lock: ffff888011dd12f0 (&htab->lockdep_key#2){....}-{2:2}, at: htab_lock_bucket+0x1a4/0x370 kernel/bpf/hashtab.c:167 but task is already holding lock: ffff888025fea458 (&htab->lockdep_key#3){....}-{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#3){....}-{2:2}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759 __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:1462 bpf_prog_6f5f05285f674219+0x43/0x4c bpf_dispatcher_nop_func include/linux/bpf.h:1252 [inline] __bpf_prog_run include/linux/filter.h:691 [inline] bpf_prog_run include/linux/filter.h:698 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2338 [inline] bpf_trace_run2+0x2ec/0x540 kernel/trace/bpf_trace.c:2379 __traceiter_contention_begin+0x7b/0xb0 include/trace/events/lock.h:95 trace_contention_begin+0x117/0x140 include/trace/events/lock.h:95 __pv_queued_spin_lock_slowpath+0x114/0xdc0 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:1462 0xffffffffa0003c4b bpf_dispatcher_nop_func include/linux/bpf.h:1252 [inline] __bpf_prog_run include/linux/filter.h:691 [inline] bpf_prog_run include/linux/filter.h:698 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2338 [inline] bpf_trace_run2+0x2ec/0x540 kernel/trace/bpf_trace.c:2379 __traceiter_contention_begin+0x7b/0xb0 include/trace/events/lock.h:95 trace_contention_begin+0xf5/0x120 include/trace/events/lock.h:95 __mutex_lock_common kernel/locking/mutex.c:610 [inline] __mutex_lock+0x147/0xd70 kernel/locking/mutex.c:752 tracepoint_probe_unregister+0x32/0x990 kernel/tracepoint.c:548 bpf_raw_tp_link_release+0x45/0x70 kernel/bpf/syscall.c:3541 bpf_link_free+0xf5/0x250 kernel/bpf/syscall.c:3067 bpf_link_put_direct kernel/bpf/syscall.c:3107 [inline] bpf_link_release+0x7b/0x90 kernel/bpf/syscall.c:3114 __fput+0x24a/0x8a0 fs/file_table.c:422 task_work_run+0x24f/0x310 kernel/task_work.c:222 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x168/0x370 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (&htab->lockdep_key#2){....}-{2:2}: check_prev_add kernel/locking/lockdep.c:3133 [inline] check_prevs_add kernel/locking/lockdep.c:3252 [inline] validate_chain+0x18e0/0x5900 kernel/locking/lockdep.c:3868 __lock_acquire+0x137a/0x2040 kernel/locking/lockdep.c:5142 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759 __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:1462 0xffffffffa0003c4b bpf_dispatcher_nop_func include/linux/bpf.h:1252 [inline] __bpf_prog_run include/linux/filter.h:691 [inline] bpf_prog_run include/linux/filter.h:698 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2338 [inline] bpf_trace_run2+0x2ec/0x540 kernel/trace/bpf_trace.c:2379 __traceiter_contention_begin+0x7b/0xb0 include/trace/events/lock.h:95 trace_contention_begin+0x117/0x140 include/trace/events/lock.h:95 __pv_queued_spin_lock_slowpath+0x114/0xdc0 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:1462 bpf_prog_6f5f05285f674219+0x43/0x4c bpf_dispatcher_nop_func include/linux/bpf.h:1252 [inline] __bpf_prog_run include/linux/filter.h:691 [inline] bpf_prog_run include/linux/filter.h:698 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2338 [inline] bpf_trace_run2+0x2ec/0x540 kernel/trace/bpf_trace.c:2379 __traceiter_contention_begin+0x7b/0xb0 include/trace/events/lock.h:95 trace_contention_begin+0xf5/0x120 include/trace/events/lock.h:95 __mutex_lock_common kernel/locking/mutex.c:610 [inline] __mutex_lock+0x147/0xd70 kernel/locking/mutex.c:752 tracepoint_probe_unregister+0x32/0x990 kernel/tracepoint.c:548 bpf_raw_tp_link_release+0x45/0x70 kernel/bpf/syscall.c:3541 bpf_link_free+0xf5/0x250 kernel/bpf/syscall.c:3067 bpf_link_put_direct kernel/bpf/syscall.c:3107 [inline] bpf_link_release+0x7b/0x90 kernel/bpf/syscall.c:3114 __fput+0x24a/0x8a0 fs/file_table.c:422 task_work_run+0x24f/0x310 kernel/task_work.c:222 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x168/0x370 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 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#3); lock(&htab->lockdep_key#2); lock(&htab->lockdep_key#3); lock(&htab->lockdep_key#2); *** DEADLOCK *** 4 locks held by syz.4.306/6866: #0: ffffffff8e984a68 (tracepoints_mutex){+.+.}-{3:3}, at: tracepoint_probe_unregister+0x32/0x990 kernel/tracepoint.c:548 #1: ffffffff8e937660 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline] #1: ffffffff8e937660 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #1: ffffffff8e937660 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2337 [inline] #1: ffffffff8e937660 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x1fc/0x540 kernel/trace/bpf_trace.c:2379 #2: ffff888025fea458 (&htab->lockdep_key#3){....}-{2:2}, at: htab_lock_bucket+0x1a4/0x370 kernel/bpf/hashtab.c:167 #3: ffffffff8e937660 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline] #3: ffffffff8e937660 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #3: ffffffff8e937660 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2337 [inline] #3: ffffffff8e937660 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x1fc/0x540 kernel/trace/bpf_trace.c:2379 stack backtrace: CPU: 1 UID: 0 PID: 6866 Comm: syz.4.306 Not tainted 6.10.0-syzkaller-12690-gfdf1c728fac5 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 Call Trace: __dump_stack lib/dump_stack.c:93 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2186 check_prev_add kernel/locking/lockdep.c:3133 [inline] check_prevs_add kernel/locking/lockdep.c:3252 [inline] validate_chain+0x18e0/0x5900 kernel/locking/lockdep.c:3868 __lock_acquire+0x137a/0x2040 kernel/locking/lockdep.c:5142 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759 __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:1462