============================================ WARNING: possible recursive locking detected 6.9.0-rc5-syzkaller-00042-ge88c4cfcb7b8 #0 Not tainted -------------------------------------------- syz-executor.1/16724 is trying to acquire lock: ffff8880566da1d8 (&qs->lock){-.-.}-{2:2}, at: __queue_map_get+0x14b/0x4d0 kernel/bpf/queue_stack_maps.c:105 but task is already holding lock: ffff8880637e99d8 (&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-executor.1/16724: #0: ffff88806e7706d0 (&type->i_mutex_dir_key#26){.+.+}-{3:3}, at: inode_lock_shared include/linux/fs.h:805 [inline] #0: ffff88806e7706d0 (&type->i_mutex_dir_key#26){.+.+}-{3:3}, at: lookup_slow+0x45/0x70 fs/namei.c:1708 #1: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #1: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #1: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2380 [inline] #1: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run3+0x14a/0x460 kernel/trace/bpf_trace.c:2421 #2: ffff8880637e99d8 (&qs->lock){-.-.}-{2:2}, at: queue_stack_map_push_elem+0x1b2/0x660 kernel/bpf/queue_stack_maps.c:210 #3: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #3: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #3: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2380 [inline] #3: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x114/0x420 kernel/trace/bpf_trace.c:2420 stack backtrace: CPU: 1 PID: 16724 Comm: syz-executor.1 Not tainted 6.9.0-rc5-syzkaller-00042-ge88c4cfcb7b8 #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+0x241/0x360 lib/dump_stack.c:114 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+0x1ed/0x550 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 __queue_map_get+0x14b/0x4d0 kernel/bpf/queue_stack_maps.c:105 bpf_prog_00798911c748094f+0x42/0x46 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 trace_contention_end+0x114/0x140 include/trace/events/lock.h:122 __pv_queued_spin_lock_slowpath+0x939/0xc60 kernel/locking/qspinlock.c:560 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+0x3f/0x43 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_run3+0x238/0x460 kernel/trace/bpf_trace.c:2421 trace_kmem_cache_free include/trace/events/kmem.h:114 [inline] kmem_cache_free+0x25a/0x2c0 mm/slub.c:4343 free_buffer_head+0x55/0x240 fs/buffer.c:3017 try_to_free_buffers+0x311/0x5f0 fs/buffer.c:2958 shrink_folio_list+0x273f/0x8ca0 mm/vmscan.c:1376 shrink_inactive_list mm/vmscan.c:1926 [inline] shrink_list mm/vmscan.c:2163 [inline] shrink_lruvec+0x1638/0x2e40 mm/vmscan.c:5687 shrink_node_memcgs mm/vmscan.c:5873 [inline] shrink_node+0x1189/0x2d60 mm/vmscan.c:5908 shrink_zones mm/vmscan.c:6152 [inline] do_try_to_free_pages+0x695/0x1af0 mm/vmscan.c:6214 try_to_free_mem_cgroup_pages+0x47a/0xad0 mm/vmscan.c:6529 try_charge_memcg+0x6da/0x18a0 mm/memcontrol.c:2783 try_charge mm/memcontrol.c:2931 [inline] charge_memcg+0xa2/0x160 mm/memcontrol.c:7284 __mem_cgroup_charge+0x27/0x80 mm/memcontrol.c:7299 mem_cgroup_charge include/linux/memcontrol.h:691 [inline] __filemap_add_folio+0x3d8/0x1a80 mm/filemap.c:864 filemap_add_folio+0x11e/0x570 mm/filemap.c:947 do_read_cache_folio+0x10a/0x820 mm/filemap.c:3714 do_read_cache_page+0x30/0x200 mm/filemap.c:3813 read_mapping_page include/linux/pagemap.h:888 [inline] dir_get_page fs/sysv/dir.c:64 [inline] sysv_find_entry+0x1af/0x410 fs/sysv/dir.c:157 sysv_inode_by_name+0x98/0x1f0 fs/sysv/dir.c:374 sysv_lookup+0x6b/0xe0 fs/sysv/namei.c:38 __lookup_slow+0x28c/0x3f0 fs/namei.c:1692 lookup_slow+0x53/0x70 fs/namei.c:1709 walk_component+0x2e1/0x410 fs/namei.c:2004 lookup_last fs/namei.c:2461 [inline] path_lookupat+0x16f/0x450 fs/namei.c:2485 filename_lookup+0x256/0x610 fs/namei.c:2514 user_path_at_empty+0x42/0x60 fs/namei.c:2921 user_path_at include/linux/namei.h:57 [inline] __do_sys_chdir fs/open.c:558 [inline] __se_sys_chdir+0xbf/0x220 fs/open.c:552 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f3c5b47dea9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f3c5c1e60c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000050 RAX: ffffffffffffffda RBX: 00007f3c5b5ac050 RCX: 00007f3c5b47dea9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000040 RBP: 00007f3c5b4ca4a4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000006e R14: 00007f3c5b5ac050 R15: 00007ffdbb4a53a8