============================================ WARNING: possible recursive locking detected 6.1.83-syzkaller #0 Not tainted -------------------------------------------- syz-executor389/3550 is trying to acquire lock: ffff88807be5f238 (&trie->lock){....}-{2:2}, at: trie_delete_elem+0x90/0x690 kernel/bpf/lpm_trie.c:451 but task is already holding lock: ffff88807be5fa38 (&trie->lock){....}-{2:2}, at: trie_delete_elem+0x90/0x690 kernel/bpf/lpm_trie.c:451 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&trie->lock); lock(&trie->lock); *** DEADLOCK *** May be due to missing lock nesting notation 9 locks held by syz-executor389/3550: #0: ffffffff8d1c5290 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mmap kernel/fork.c:592 [inline] #0: ffffffff8d1c5290 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mm kernel/fork.c:1540 [inline] #0: ffffffff8d1c5290 (dup_mmap_sem){.+.+}-{0:0}, at: copy_mm+0x3cb/0x1990 kernel/fork.c:1589 #1: ffff8880290897d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline] #1: ffff8880290897d8 (&mm->mmap_lock){++++}-{3:3}, at: dup_mmap kernel/fork.c:593 [inline] #1: ffff8880290897d8 (&mm->mmap_lock){++++}-{3:3}, at: dup_mm kernel/fork.c:1540 [inline] #1: ffff8880290897d8 (&mm->mmap_lock){++++}-{3:3}, at: copy_mm+0x3e5/0x1990 kernel/fork.c:1589 #2: ffff888029089058 (&mm->mmap_lock/1){+.+.}-{3:3}, at: mmap_write_lock_nested include/linux/mmap_lock.h:78 [inline] #2: ffff888029089058 (&mm->mmap_lock/1){+.+.}-{3:3}, at: dup_mmap kernel/fork.c:602 [inline] #2: ffff888029089058 (&mm->mmap_lock/1){+.+.}-{3:3}, at: dup_mm kernel/fork.c:1540 [inline] #2: ffff888029089058 (&mm->mmap_lock/1){+.+.}-{3:3}, at: copy_mm+0x4ca/0x1990 kernel/fork.c:1589 #3: ffff888022305b58 (ptlock_ptr(page)#2){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] #3: ffff888022305b58 (ptlock_ptr(page)#2){+.+.}-{2:2}, at: copy_pte_range mm/memory.c:1042 [inline] #3: ffff888022305b58 (ptlock_ptr(page)#2){+.+.}-{2:2}, at: copy_pmd_range mm/memory.c:1177 [inline] #3: ffff888022305b58 (ptlock_ptr(page)#2){+.+.}-{2:2}, at: copy_pud_range mm/memory.c:1214 [inline] #3: ffff888022305b58 (ptlock_ptr(page)#2){+.+.}-{2:2}, at: copy_p4d_range mm/memory.c:1238 [inline] #3: ffff888022305b58 (ptlock_ptr(page)#2){+.+.}-{2:2}, at: copy_page_range+0x1148/0x4660 mm/memory.c:1336 #4: ffffffff8d12a940 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #4: ffffffff8d12a940 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #4: ffffffff8d12a940 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2272 [inline] #4: ffffffff8d12a940 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run3+0x146/0x440 kernel/trace/bpf_trace.c:2313 #5: ffff88807be5fa38 (&trie->lock){....}-{2:2}, at: trie_delete_elem+0x90/0x690 kernel/bpf/lpm_trie.c:451 #6: ffff8880b9928118 (krc.lock){....}-{2:2}, at: krc_this_cpu_lock kernel/rcu/tree.c:2990 [inline] #6: ffff8880b9928118 (krc.lock){....}-{2:2}, at: add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3310 [inline] #6: ffff8880b9928118 (krc.lock){....}-{2:2}, at: kvfree_call_rcu+0x1b2/0x8c0 kernel/rcu/tree.c:3401 #7: ffff8880b9928358 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x120/0x260 kernel/time/timer.c:999 #8: ffffffff8d12a940 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #8: ffffffff8d12a940 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #8: ffffffff8d12a940 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2272 [inline] #8: ffffffff8d12a940 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run3+0x146/0x440 kernel/trace/bpf_trace.c:2313 stack backtrace: CPU: 1 PID: 3550 Comm: syz-executor389 Not tainted 6.1.83-syzkaller #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+0x1e3/0x2cb lib/dump_stack.c:106 print_deadlock_bug kernel/locking/lockdep.c:2983 [inline] check_deadlock kernel/locking/lockdep.c:3026 [inline] validate_chain+0x4711/0x5950 kernel/locking/lockdep.c:3812 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 __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:451 bpf_prog_2c29ac5cdc6b1842+0x3a/0x3e bpf_dispatcher_nop_func include/linux/bpf.h:989 [inline] __bpf_prog_run include/linux/filter.h:603 [inline] bpf_prog_run include/linux/filter.h:610 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2273 [inline] bpf_trace_run3+0x231/0x440 kernel/trace/bpf_trace.c:2313 trace_timer_start include/trace/events/timer.h:53 [inline] enqueue_timer+0x440/0x600 kernel/time/timer.c:609 __mod_timer+0x92b/0xee0 queue_delayed_work_on+0x156/0x250 kernel/workqueue.c:1704 queue_delayed_work include/linux/workqueue.h:527 [inline] schedule_delayed_monitor_work kernel/rcu/tree.c:3171 [inline] kvfree_call_rcu+0x520/0x8c0 kernel/rcu/tree.c:3427 trie_delete_elem+0x520/0x690 bpf_prog_2c29ac5cdc6b1842+0x3a/0x3e bpf_dispatcher_nop_func include/linux/bpf.h:989 [inline] __bpf_prog_run include/linux/filter.h:603 [inline] bpf_prog_run include/linux/filter.h:610 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2273 [inline] bpf_trace_run3+0x231/0x440 kernel/trace/bpf_trace.c:2313 __bpf_trace_rss_stat+0x94/0xc0 include/trace/events/kmem.h:346 trace_rss_stat include/trace/events/kmem.h:346 [inline] mm_trace_rss_stat+0x1f4/0x280 mm/memory.c:167 add_mm_counter include/linux/mm.h:2105 [inline] add_mm_rss_vec+0x110/0x260 mm/memory.c:509 copy_pte_range mm/memory.c:1115 [inline] copy_pmd_range mm/memory.c:1177 [inline] copy_pud_range mm/memory.c:1214 [inline] copy_p4d_range mm/memory.c:1238 [inline] copy_page_range+0x3c96/0x4660 mm/memory.c:1336 dup_mmap kernel/fork.c:696 [inline] dup_mm kernel/fork.c:1540 [inline] copy_mm+0xf42/0x1990 kernel/fork.c:1589 copy_process+0x19d5/0x4060 kernel/fork.c:2267 kernel_clone+0x222/0x920 kernel/fork.c:2682 __do_sys_clone kernel/fork.c:2823 [inline] __se_sys_clone kernel/fork.c:2807 [inline] __x64_sys_clone+0x231/0x280 kernel/fork.c:2807 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f7c52f3a3b3 Code: 1f 84 00 00 00 00 00 64 48 8b 04 25 10 00 00 00 45 31 c0 31 d2 31 f6 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 89 c2 85 c0 75 2c 64 48 8b 04 25 10 00 00 RSP: 002b:00007ffc17e0baf8 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f7c52f3a3b3 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000000 R08: 0000000000000000 R09: 00007f7c52fbaaa0 R10: 0000555556911650 R11: 0000000000000246 R12: 0000000000000001 R13: 00007f7c52fb3800 R14: 00007ffc17e0bc20 R15: 00007ffc17e0bc10