============================================ WARNING: possible recursive locking detected 6.10.0-syzkaller-04559-g7d30b8aa4fc3 #0 Not tainted -------------------------------------------- syz.4.212/6078 is trying to acquire lock: ffff888142ea99e0 (&qs->lock){..-.}-{2:2}, at: queue_stack_map_push_elem+0x1b2/0x660 kernel/bpf/queue_stack_maps.c:210 but task is already holding lock: ffff888142ea99e0 (&qs->lock){..-.}-{2:2}, at: queue_stack_map_push_elem+0x1b2/0x660 kernel/bpf/queue_stack_maps.c:210 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&qs->lock); lock(&qs->lock); *** DEADLOCK *** May be due to missing lock nesting notation 4 locks held by syz.4.212/6078: #0: ffff88804974cd98 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:106 [inline] #0: ffff88804974cd98 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x2a9/0xc80 mm/mmap.c:3349 #1: ffffffff8e735fe0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:327 [inline] #1: ffffffff8e735fe0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:839 [inline] #1: ffffffff8e735fe0 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2405 [inline] #1: ffffffff8e735fe0 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run3+0x24c/0x5a0 kernel/trace/bpf_trace.c:2448 #2: ffff888142ea99e0 (&qs->lock){..-.}-{2:2}, at: queue_stack_map_push_elem+0x1b2/0x660 kernel/bpf/queue_stack_maps.c:210 #3: ffffffff8e735fe0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:327 [inline] #3: ffffffff8e735fe0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:839 [inline] #3: ffffffff8e735fe0 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2405 [inline] #3: ffffffff8e735fe0 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x1fc/0x540 kernel/trace/bpf_trace.c:2447 stack backtrace: CPU: 0 PID: 6078 Comm: syz.4.212 Not tainted 6.10.0-syzkaller-04559-g7d30b8aa4fc3 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 check_deadlock kernel/locking/lockdep.c:3061 [inline] validate_chain+0x15d3/0x5900 kernel/locking/lockdep.c:3855 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5136 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5753 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 queue_stack_map_push_elem+0x1b2/0x660 kernel/bpf/queue_stack_maps.c:210 bpf_prog_216c997a1f42e404+0x40/0x44 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:2406 [inline] bpf_trace_run2+0x2ec/0x540 kernel/trace/bpf_trace.c:2447 trace_contention_end+0x114/0x140 include/trace/events/lock.h:122 __pv_queued_spin_lock_slowpath+0xb81/0xdc0 kernel/locking/qspinlock.c:557 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 queue_stack_map_push_elem+0x1b2/0x660 kernel/bpf/queue_stack_maps.c:210 bpf_prog_216c997a1f42e404+0x40/0x44 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:2406 [inline] bpf_trace_run3+0x33a/0x5a0 kernel/trace/bpf_trace.c:2448 trace_kmem_cache_free include/trace/events/kmem.h:114 [inline] kmem_cache_free+0x2a9/0x350 mm/slub.c:4512 anon_vma_free mm/rmap.c:137 [inline] __put_anon_vma+0x128/0x2d0 mm/rmap.c:2527 put_anon_vma include/linux/rmap.h:116 [inline] unlink_anon_vmas+0x492/0x5f0 mm/rmap.c:444 free_pgtables+0x4ca/0x730 mm/memory.c:404 exit_mmap+0x447/0xc80 mm/mmap.c:3352 __mmput+0x115/0x390 kernel/fork.c:1343 exit_mm+0x220/0x310 kernel/exit.c:566 do_exit+0x9b2/0x27f0 kernel/exit.c:864 do_group_exit+0x207/0x2c0 kernel/exit.c:1026 get_signal+0x16a1/0x1740 kernel/signal.c:2917 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop kernel/entry/common.c:111 [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+0xc9/0x370 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f6d66177299 Code: Unable to access opcode bytes at 0x7f6d6617726f. RSP: 002b:00007f6d66ec60f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f6d66306138 RCX: 00007f6d66177299 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f6d66306138 RBP: 00007f6d66306130 R08: 00007f6d66ec66c0 R09: 00007f6d66ec66c0 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f6d6630613c R13: 000000000000000b R14: 00007ffce8ba2da0 R15: 00007ffce8ba2e88