====================================================== WARNING: possible circular locking dependency detected 5.15.168-syzkaller #0 Not tainted ------------------------------------------------------ syz.2.121/3987 is trying to acquire lock: ffff8880b9027e78 (krc.lock){..-.}-{2:2}, at: krc_this_cpu_lock kernel/rcu/tree.c:3199 [inline] ffff8880b9027e78 (krc.lock){..-.}-{2:2}, at: add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3506 [inline] ffff8880b9027e78 (krc.lock){..-.}-{2:2}, at: kvfree_call_rcu+0x1b5/0x8a0 kernel/rcu/tree.c:3597 but task is already holding lock: ffff88807854a1b8 (&trie->lock){....}-{2:2}, at: trie_update_elem+0xc5/0xc00 kernel/bpf/lpm_trie.c:323 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&trie->lock){....}-{2:2}: lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 trie_delete_elem+0x90/0x690 kernel/bpf/lpm_trie.c:450 0xffffffffa0018a6d bpf_dispatcher_nop_func include/linux/bpf.h:790 [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:1880 [inline] bpf_trace_run1+0x168/0x2f0 kernel/trace/bpf_trace.c:1916 __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+0x79b/0x8e0 mm/page_alloc.c:3465 release_pages+0x1bb9/0x1f40 mm/swap.c:963 __pagevec_release+0x80/0xf0 mm/swap.c:983 pagevec_release include/linux/pagevec.h:81 [inline] shmem_undo_range+0x67a/0x1b50 mm/shmem.c:964 shmem_truncate_range mm/shmem.c:1063 [inline] shmem_fallocate+0x433/0xfb0 mm/shmem.c:2701 vfs_fallocate+0x54a/0x6b0 fs/open.c:308 do_vfs_ioctl+0x2317/0x2b70 fs/ioctl.c:853 __do_sys_ioctl fs/ioctl.c:872 [inline] __se_sys_ioctl+0x81/0x160 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 -> #1 (lock){..-.}-{2:2}: lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 local_lock_acquire+0x23/0x130 include/linux/local_lock_internal.h:29 rmqueue_pcplist mm/page_alloc.c:3652 [inline] rmqueue mm/page_alloc.c:3690 [inline] get_page_from_freelist+0x27cc/0x33c0 mm/page_alloc.c:4156 __alloc_pages+0x272/0x700 mm/page_alloc.c:5423 alloc_page_interleave+0x22/0x1c0 mm/mempolicy.c:2031 alloc_slab_page mm/slub.c:1775 [inline] allocate_slab mm/slub.c:1912 [inline] new_slab+0xbb/0x4b0 mm/slub.c:1975 ___slab_alloc+0x6f6/0xe10 mm/slub.c:3008 __slab_alloc mm/slub.c:3095 [inline] slab_alloc_node mm/slub.c:3186 [inline] slab_alloc mm/slub.c:3228 [inline] kmem_cache_alloc+0x18e/0x280 mm/slub.c:3233 kmem_cache_zalloc include/linux/slab.h:711 [inline] fill_pool lib/debugobjects.c:172 [inline] __debug_object_init+0x77a/0xd30 lib/debugobjects.c:615 debug_hrtimer_init kernel/time/hrtimer.c:414 [inline] debug_init+0x24/0x200 kernel/time/hrtimer.c:468 hrtimer_init+0x1e/0x30 kernel/time/hrtimer.c:1595 run_page_cache_worker kernel/rcu/tree.c:3486 [inline] kvfree_call_rcu+0x66b/0x8a0 kernel/rcu/tree.c:3599 rtnl_register_internal+0x443/0x530 net/core/rtnetlink.c:223 rtnl_register+0x32/0x70 net/core/rtnetlink.c:273 ip_rt_init+0x2e6/0x390 net/ipv4/route.c:3750 ip_init+0xa/0x20 net/ipv4/ip_output.c:1749 inet_init+0x27c/0x390 net/ipv4/af_inet.c:2009 do_one_initcall+0x22b/0x7a0 init/main.c:1302 do_initcall_level+0x157/0x210 init/main.c:1375 do_initcalls+0x49/0x90 init/main.c:1391 kernel_init_freeable+0x425/0x5c0 init/main.c:1615 kernel_init+0x19/0x290 init/main.c:1506 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 -> #0 (krc.lock){..-.}-{2:2}: check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain+0x1649/0x5930 kernel/locking/lockdep.c:3788 __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154 krc_this_cpu_lock kernel/rcu/tree.c:3199 [inline] add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3506 [inline] kvfree_call_rcu+0x1b5/0x8a0 kernel/rcu/tree.c:3597 trie_update_elem+0x808/0xc00 kernel/bpf/lpm_trie.c:384 bpf_map_update_value+0x5d7/0x6c0 kernel/bpf/syscall.c:221 generic_map_update_batch+0x54d/0x8b0 kernel/bpf/syscall.c:1421 bpf_map_do_batch+0x4d0/0x620 __sys_bpf+0x55c/0x670 __do_sys_bpf kernel/bpf/syscall.c:4755 [inline] __se_sys_bpf kernel/bpf/syscall.c:4753 [inline] __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:4753 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 other info that might help us debug this: Chain exists of: krc.lock --> lock --> &trie->lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&trie->lock); lock(lock); lock(&trie->lock); lock(krc.lock); *** DEADLOCK *** 2 locks held by syz.2.121/3987: #0: ffffffff8c91fc20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:311 #1: ffff88807854a1b8 (&trie->lock){....}-{2:2}, at: trie_update_elem+0xc5/0xc00 kernel/bpf/lpm_trie.c:323 stack backtrace: CPU: 0 PID: 3987 Comm: syz.2.121 Not tainted 5.15.168-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106 check_noncircular+0x2f8/0x3b0 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+0x1649/0x5930 kernel/locking/lockdep.c:3788 __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154 krc_this_cpu_lock kernel/rcu/tree.c:3199 [inline] add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3506 [inline] kvfree_call_rcu+0x1b5/0x8a0 kernel/rcu/tree.c:3597 trie_update_elem+0x808/0xc00 kernel/bpf/lpm_trie.c:384 bpf_map_update_value+0x5d7/0x6c0 kernel/bpf/syscall.c:221 generic_map_update_batch+0x54d/0x8b0 kernel/bpf/syscall.c:1421 bpf_map_do_batch+0x4d0/0x620 __sys_bpf+0x55c/0x670 __do_sys_bpf kernel/bpf/syscall.c:4755 [inline] __se_sys_bpf kernel/bpf/syscall.c:4753 [inline] __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:4753 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f9dd0f61ff9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f9dcf3da038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f9dd1119f80 RCX: 00007f9dd0f61ff9 RDX: 0000000000000038 RSI: 0000000020000240 RDI: 000000000000001a RBP: 00007f9dd0fd4296 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f9dd1119f80 R15: 00007ffd5f43e968