syzbot

======================================================
WARNING: possible circular locking dependency detected
6.10.0-rc5-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor.0/11734 is trying to acquire lock:
ffff88801504e618 (&n->list_lock){-.-.}-{2:2}, at: get_partial_node+0x36/0x280 mm/slub.c:2676

but task is already holding lock:
ffff888061bdc1f8 (&trie->lock){-.-.}-{2:2}, at: trie_update_elem+0xc8/0xc00 kernel/bpf/lpm_trie.c:333

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&trie->lock){-.-.}-{2:2}:
       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
       trie_delete_elem+0x96/0x6a0 kernel/bpf/lpm_trie.c:462
       bpf_prog_00798911c748094f+0x46/0x46
       bpf_dispatcher_nop_func include/linux/bpf.h:1243 [inline]
       __bpf_prog_run include/linux/filter.h:691 [inline]
       bpf_prog_run include/linux/filter.h:698 [inline]
       __bpf_trace_run kernel/trace/bpf_trace.c:2403 [inline]
       bpf_trace_run2+0x2ec/0x540 kernel/trace/bpf_trace.c:2444
       trace_contention_end+0x114/0x140 include/trace/events/lock.h:122
       __pv_queued_spin_lock_slowpath+0xb81/0xdc0 kernel/locking/qspinlock.c:557
       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
       get_partial_node+0x36/0x280 mm/slub.c:2676
       get_partial mm/slub.c:2790 [inline]
       ___slab_alloc+0xc17/0x14b0 mm/slub.c:3647
       __slab_alloc+0x58/0xa0 mm/slub.c:3757
       __slab_alloc_node mm/slub.c:3810 [inline]
       slab_alloc_node mm/slub.c:3989 [inline]
       __do_kmalloc_node mm/slub.c:4121 [inline]
       kmalloc_node_track_caller_noprof+0x281/0x440 mm/slub.c:4142
       kmalloc_reserve+0x111/0x2a0 net/core/skbuff.c:597
       __alloc_skb+0x1f3/0x440 net/core/skbuff.c:666
       alloc_skb include/linux/skbuff.h:1308 [inline]
       nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:748 [inline]
       nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline]
       nsim_dev_trap_report_work+0x254/0xaa0 drivers/net/netdevsim/dev.c:850
       process_one_work kernel/workqueue.c:3231 [inline]
       process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3312
       worker_thread+0x86d/0xd70 kernel/workqueue.c:3393
       kthread+0x2f0/0x390 kernel/kthread.c:389
       ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

-> #0 (&n->list_lock){-.-.}-{2:2}:
       check_prev_add kernel/locking/lockdep.c:3134 [inline]
       check_prevs_add kernel/locking/lockdep.c:3253 [inline]
       validate_chain+0x18e0/0x5900 kernel/locking/lockdep.c:3869
       __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
       get_partial_node+0x36/0x280 mm/slub.c:2676
       get_partial mm/slub.c:2790 [inline]
       ___slab_alloc+0xc17/0x14b0 mm/slub.c:3647
       __slab_alloc+0x58/0xa0 mm/slub.c:3757
       __slab_alloc_node mm/slub.c:3810 [inline]
       slab_alloc_node mm/slub.c:3989 [inline]
       __do_kmalloc_node mm/slub.c:4121 [inline]
       __kmalloc_node_noprof+0x286/0x440 mm/slub.c:4129
       kmalloc_node_noprof include/linux/slab.h:681 [inline]
       bpf_map_kmalloc_node+0xd3/0x1c0 kernel/bpf/syscall.c:422
       lpm_trie_node_alloc kernel/bpf/lpm_trie.c:299 [inline]
       trie_update_elem+0x1cd/0xc00 kernel/bpf/lpm_trie.c:342
       bpf_map_update_value+0x4d3/0x540 kernel/bpf/syscall.c:203
       generic_map_update_batch+0x60d/0x900 kernel/bpf/syscall.c:1889
       bpf_map_do_batch+0x3e0/0x690 kernel/bpf/syscall.c:5197
       __sys_bpf+0x377/0x810
       __do_sys_bpf kernel/bpf/syscall.c:5795 [inline]
       __se_sys_bpf kernel/bpf/syscall.c:5793 [inline]
       __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5793
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&trie->lock);
                               lock(&n->list_lock);
                               lock(&trie->lock);
  lock(&n->list_lock);

 *** DEADLOCK ***

2 locks held by syz-executor.0/11734:
 #0: ffffffff8e333fa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline]
 #0: ffffffff8e333fa0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline]
 #0: ffffffff8e333fa0 (rcu_read_lock){....}-{1:2}, at: bpf_map_update_value+0x3c4/0x540 kernel/bpf/syscall.c:202
 #1: ffff888061bdc1f8 (&trie->lock){-.-.}-{2:2}, at: trie_update_elem+0xc8/0xc00 kernel/bpf/lpm_trie.c:333

stack backtrace:
CPU: 1 PID: 11734 Comm: syz-executor.0 Not tainted 6.10.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2187
 check_prev_add kernel/locking/lockdep.c:3134 [inline]
 check_prevs_add kernel/locking/lockdep.c:3253 [inline]
 validate_chain+0x18e0/0x5900 kernel/locking/lockdep.c:3869
 __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
 get_partial_node+0x36/0x280 mm/slub.c:2676
 get_partial mm/slub.c:2790 [inline]
 ___slab_alloc+0xc17/0x14b0 mm/slub.c:3647
 __slab_alloc+0x58/0xa0 mm/slub.c:3757
 __slab_alloc_node mm/slub.c:3810 [inline]
 slab_alloc_node mm/slub.c:3989 [inline]
 __do_kmalloc_node mm/slub.c:4121 [inline]
 __kmalloc_node_noprof+0x286/0x440 mm/slub.c:4129
 kmalloc_node_noprof include/linux/slab.h:681 [inline]
 bpf_map_kmalloc_node+0xd3/0x1c0 kernel/bpf/syscall.c:422
 lpm_trie_node_alloc kernel/bpf/lpm_trie.c:299 [inline]
 trie_update_elem+0x1cd/0xc00 kernel/bpf/lpm_trie.c:342
 bpf_map_update_value+0x4d3/0x540 kernel/bpf/syscall.c:203
 generic_map_update_batch+0x60d/0x900 kernel/bpf/syscall.c:1889
 bpf_map_do_batch+0x3e0/0x690 kernel/bpf/syscall.c:5197
 __sys_bpf+0x377/0x810
 __do_sys_bpf kernel/bpf/syscall.c:5795 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5793 [inline]
 __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5793
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9011a7d0a9
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:00007f90115de0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007f9011bb4050 RCX: 00007f9011a7d0a9
RDX: 0000000000000038 RSI: 0000000020000000 RDI: 000000000000001a
RBP: 00007f9011aec074 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000006e R14: 00007f9011bb4050 R15: 00007ffc0f374d28
 </TASK>