====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ udevd/4295 is trying to acquire lock: ffff88807ac6ea38 (&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+0x1436/0x1ca0 mm/page_alloc.c:4189 __alloc_pages+0x1ee/0x480 mm/page_alloc.c:5487 __alloc_pages_node include/linux/gfp.h:570 [inline] alloc_slab_page mm/slub.c:1782 [inline] allocate_slab mm/slub.c:1917 [inline] new_slab+0xb6/0x4b0 mm/slub.c:1980 ___slab_alloc+0x80a/0xdd0 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:630 [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 map_update_elem+0x626/0x770 kernel/bpf/syscall.c:1194 __sys_bpf+0x46b/0x6f0 kernel/bpf/syscall.c:4645 __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+0x2c42/0x7d10 kernel/locking/lockdep.c:5012 lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xb0/0x100 kernel/locking/spinlock.c:162 trie_delete_elem+0x90/0x710 kernel/bpf/lpm_trie.c:467 bpf_prog_1c0c44170264bb34+0x3d/0xda0 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+0x159/0x2e0 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+0x6e9/0x820 mm/page_alloc.c:3465 release_pages+0x186c/0x1be0 mm/swap.c:963 __pagevec_release+0x6d/0xe0 mm/swap.c:983 pagevec_release include/linux/pagevec.h:81 [inline] shmem_undo_range+0x62b/0x1930 mm/shmem.c:964 shmem_truncate_range mm/shmem.c:1063 [inline] shmem_evict_inode+0x220/0xa40 mm/shmem.c:1145 evict+0x4c9/0x8d0 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+0x8c7/0xf60 fs/namei.c:4995 __do_sys_rename fs/namei.c:5039 [inline] __se_sys_rename fs/namei.c:5037 [inline] __x64_sys_rename+0x82/0x90 fs/namei.c:5037 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/4295: #0: ffff88807eaea460 (sb_writers#3){.+.+}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:386 #1: ffff88802b505fc0 (&type->i_mutex_dir_key#3/1){+.+.}-{3:3}, at: lock_rename include/linux/fs.h:-1 [inline] #1: ffff88802b505fc0 (&type->i_mutex_dir_key#3/1){+.+.}-{3:3}, at: do_renameat2+0x43d/0xf60 fs/namei.c:4932 #2: ffff8880b9035df8 (lock){-.-.}-{2:2}, at: local_lock_acquire+0x5/0x120 include/linux/local_lock_internal.h:28 #3: ffffffff8c31eaa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:312 stack backtrace: CPU: 0 PID: 4295 Comm: udevd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106 check_noncircular+0x296/0x330 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+0x2c42/0x7d10 kernel/locking/lockdep.c:5012 lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xb0/0x100 kernel/locking/spinlock.c:162 trie_delete_elem+0x90/0x710 kernel/bpf/lpm_trie.c:467 bpf_prog_1c0c44170264bb34+0x3d/0xda0 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+0x159/0x2e0 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+0x6e9/0x820 mm/page_alloc.c:3465 release_pages+0x186c/0x1be0 mm/swap.c:963 __pagevec_release+0x6d/0xe0 mm/swap.c:983 pagevec_release include/linux/pagevec.h:81 [inline] shmem_undo_range+0x62b/0x1930 mm/shmem.c:964 shmem_truncate_range mm/shmem.c:1063 [inline] shmem_evict_inode+0x220/0xa40 mm/shmem.c:1145 evict+0x4c9/0x8d0 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+0x8c7/0xf60 fs/namei.c:4995 __do_sys_rename fs/namei.c:5039 [inline] __se_sys_rename fs/namei.c:5037 [inline] __x64_sys_rename+0x82/0x90 fs/namei.c:5037 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: 0033:0x7fd4a4672cc7 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:00007ffc875c1c68 EFLAGS: 00000206 ORIG_RAX: 0000000000000052 RAX: ffffffffffffffda RBX: 00005579608f86a0 RCX: 00007fd4a4672cc7 RDX: 00005579608cc010 RSI: 00007ffc875c1c80 RDI: 00007ffc875c2080 RBP: 00005579608dfe20 R08: 00000000000001e0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 00007ffc875c1c80 R13: 00007ffc875c2080 R14: 0000000000000000 R15: 0000557950bc39dd