====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ udevd/4950 is trying to acquire lock: ffff888077e3ea38 (&trie->lock){....}-{2:2}, at: trie_delete_elem+0x90/0x710 kernel/bpf/lpm_trie.c:467 but task is already holding lock: ffff8880b9035df8 (lock){..-.}-{2:2}, at: local_lock_acquire+0x5/0x120 include/linux/local_lock_internal.h:28 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (lock){..-.}-{2:2}: local_lock_acquire+0x2b/0x120 include/linux/local_lock_internal.h:29 rmqueue_pcplist mm/page_alloc.c:3699 [inline] rmqueue mm/page_alloc.c:3742 [inline] get_page_from_freelist+0x141e/0x1c60 mm/page_alloc.c:4189 __alloc_pages+0x1e1/0x470 mm/page_alloc.c:5487 alloc_slab_page mm/slub.c:1780 [inline] allocate_slab mm/slub.c:1917 [inline] new_slab+0xc0/0x4b0 mm/slub.c:1980 ___slab_alloc+0x81e/0xdf0 mm/slub.c:3013 __slab_alloc mm/slub.c:3100 [inline] slab_alloc_node mm/slub.c:3191 [inline] __kmalloc_node+0x200/0x3b0 mm/slub.c:4456 kmalloc_node include/linux/slab.h:627 [inline] bpf_map_kmalloc_node+0xba/0x140 kernel/bpf/syscall.c:432 lpm_trie_node_alloc kernel/bpf/lpm_trie.c:290 [inline] trie_update_elem+0x1cc/0xc50 kernel/bpf/lpm_trie.c:332 bpf_map_update_value+0x57d/0x650 kernel/bpf/syscall.c:223 generic_map_update_batch+0x525/0x7c0 kernel/bpf/syscall.c:1430 bpf_map_do_batch+0x466/0x600 kernel/bpf/syscall.c:-1 __sys_bpf+0x601/0x670 kernel/bpf/syscall.c:-1 __do_sys_bpf kernel/bpf/syscall.c:4761 [inline] __se_sys_bpf kernel/bpf/syscall.c:4759 [inline] __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:4759 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 -> #0 (&trie->lock){....}-{2:2}: check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain kernel/locking/lockdep.c:3788 [inline] __lock_acquire+0x2c33/0x7c60 kernel/locking/lockdep.c:5012 lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xa4/0xf0 kernel/locking/spinlock.c:162 trie_delete_elem+0x90/0x710 kernel/bpf/lpm_trie.c:467 bpf_prog_1c0c44170264bb34+0x3d/0x69c bpf_dispatcher_nop_func include/linux/bpf.h:888 [inline] __bpf_prog_run include/linux/filter.h:628 [inline] bpf_prog_run include/linux/filter.h:635 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:1878 [inline] bpf_trace_run1+0x153/0x2d0 kernel/trace/bpf_trace.c:1914 __bpf_trace_mm_page_free_batched+0x41/0x60 include/trace/events/kmem.h:182 trace_mm_page_free_batched include/trace/events/kmem.h:182 [inline] free_unref_page_list+0x6bb/0x7e0 mm/page_alloc.c:3465 release_pages+0x184b/0x1bb0 mm/swap.c:963 __pagevec_release+0x6d/0xe0 mm/swap.c:983 pagevec_release include/linux/pagevec.h:81 [inline] shmem_undo_range+0x5cb/0x1880 mm/shmem.c:964 shmem_truncate_range mm/shmem.c:1063 [inline] shmem_evict_inode+0x20d/0xa00 mm/shmem.c:1145 evict+0x485/0x870 fs/inode.c:647 __dentry_kill+0x431/0x650 fs/dcache.c:586 dentry_kill+0xb8/0x290 fs/dcache.c:-1 dput+0xd8/0x1a0 fs/dcache.c:893 do_renameat2+0x704/0xf70 fs/namei.c:4987 __do_sys_rename fs/namei.c:5031 [inline] __se_sys_rename fs/namei.c:5029 [inline] __x64_sys_rename+0x82/0x90 fs/namei.c:5029 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(lock); lock(&trie->lock); lock(lock); lock(&trie->lock); *** DEADLOCK *** 4 locks held by udevd/4950: #0: ffff88807e492460 (sb_writers#3){.+.+}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:377 #1: ffff88807cf81b58 (&type->i_mutex_dir_key#3/1){+.+.}-{3:3}, at: lock_rename include/linux/fs.h:-1 [inline] #1: ffff88807cf81b58 (&type->i_mutex_dir_key#3/1){+.+.}-{3:3}, at: do_renameat2+0x42a/0xf70 fs/namei.c:4924 #2: ffff8880b9035df8 (lock){..-.}-{2:2}, at: local_lock_acquire+0x5/0x120 include/linux/local_lock_internal.h:28 #3: ffffffff8c11c660 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:311 stack backtrace: CPU: 0 PID: 4950 Comm: udevd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106 check_noncircular+0x274/0x310 kernel/locking/lockdep.c:2133 check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain kernel/locking/lockdep.c:3788 [inline] __lock_acquire+0x2c33/0x7c60 kernel/locking/lockdep.c:5012 lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xa4/0xf0 kernel/locking/spinlock.c:162 trie_delete_elem+0x90/0x710 kernel/bpf/lpm_trie.c:467 bpf_prog_1c0c44170264bb34+0x3d/0x69c bpf_dispatcher_nop_func include/linux/bpf.h:888 [inline] __bpf_prog_run include/linux/filter.h:628 [inline] bpf_prog_run include/linux/filter.h:635 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:1878 [inline] bpf_trace_run1+0x153/0x2d0 kernel/trace/bpf_trace.c:1914 __bpf_trace_mm_page_free_batched+0x41/0x60 include/trace/events/kmem.h:182 trace_mm_page_free_batched include/trace/events/kmem.h:182 [inline] free_unref_page_list+0x6bb/0x7e0 mm/page_alloc.c:3465 release_pages+0x184b/0x1bb0 mm/swap.c:963 __pagevec_release+0x6d/0xe0 mm/swap.c:983 pagevec_release include/linux/pagevec.h:81 [inline] shmem_undo_range+0x5cb/0x1880 mm/shmem.c:964 shmem_truncate_range mm/shmem.c:1063 [inline] shmem_evict_inode+0x20d/0xa00 mm/shmem.c:1145 evict+0x485/0x870 fs/inode.c:647 __dentry_kill+0x431/0x650 fs/dcache.c:586 dentry_kill+0xb8/0x290 fs/dcache.c:-1 dput+0xd8/0x1a0 fs/dcache.c:893 do_renameat2+0x704/0xf70 fs/namei.c:4987 __do_sys_rename fs/namei.c:5031 [inline] __se_sys_rename fs/namei.c:5029 [inline] __x64_sys_rename+0x82/0x90 fs/namei.c:5029 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f9419e01cc7 Code: e8 5e a7 09 00 f7 d8 19 c0 5b c3 0f 1f 84 00 00 00 00 00 b8 ff ff ff ff 5b c3 66 0f 1f 84 00 00 00 00 00 b8 52 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 8b 15 01 61 17 00 f7 d8 64 89 02 b8 RSP: 002b:00007ffdc0f57858 EFLAGS: 00000202 ORIG_RAX: 0000000000000052 RAX: ffffffffffffffda RBX: 0000564c01a39bf0 RCX: 00007f9419e01cc7 RDX: 0000564c01a05010 RSI: 00007ffdc0f57870 RDI: 00007ffdc0f57c70 RBP: 0000564c01a25f60 R08: 00000000000001e0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 00007ffdc0f57870 R13: 00007ffdc0f57c70 R14: 0000000000000000 R15: 0000564bfdc279dd