============================================ WARNING: possible recursive locking detected 6.14.0-rc3-syzkaller-g6ccf6adb05d0 #0 Not tainted -------------------------------------------- syz.2.14/5976 is trying to acquire lock: ffff88814e29fa68 (&trie->lock){-.-.}-{2:2}, at: trie_delete_elem+0x96/0x6d0 kernel/bpf/lpm_trie.c:470 but task is already holding lock: ffff888030b8f268 (&trie->lock){-.-.}-{2:2}, at: trie_delete_elem+0x96/0x6d0 kernel/bpf/lpm_trie.c:470 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 5 locks held by syz.2.14/5976: #0: ffffffff8eb38f60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8eb38f60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8eb38f60 (rcu_read_lock){....}-{1:3}, at: get_mem_cgroup_from_objcg+0x1a/0x1d0 include/linux/memcontrol.h:498 #1: ffff8880b863e958 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:598 #2: ffffffff8eb38f60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #2: ffffffff8eb38f60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #2: ffffffff8eb38f60 (rcu_read_lock){....}-{1:3}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2370 [inline] #2: ffffffff8eb38f60 (rcu_read_lock){....}-{1:3}, at: bpf_trace_run4+0x244/0x590 kernel/trace/bpf_trace.c:2414 #3: ffff888030b8f268 (&trie->lock){-.-.}-{2:2}, at: trie_delete_elem+0x96/0x6d0 kernel/bpf/lpm_trie.c:470 #4: ffffffff8eb38f60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #4: ffffffff8eb38f60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #4: ffffffff8eb38f60 (rcu_read_lock){....}-{1:3}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2370 [inline] #4: ffffffff8eb38f60 (rcu_read_lock){....}-{1:3}, at: bpf_trace_run2+0x1fc/0x540 kernel/trace/bpf_trace.c:2412 stack backtrace: CPU: 0 UID: 0 PID: 5976 Comm: syz.2.14 Not tainted 6.14.0-rc3-syzkaller-g6ccf6adb05d0 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_deadlock_bug+0x483/0x620 kernel/locking/lockdep.c:3039 check_deadlock kernel/locking/lockdep.c:3091 [inline] validate_chain+0x15e2/0x5920 kernel/locking/lockdep.c:3893 __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5228 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851 __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+0x96/0x6d0 kernel/bpf/lpm_trie.c:470 bpf_prog_632b15876ecd73a2+0x49/0x4d bpf_dispatcher_nop_func include/linux/bpf.h:1290 [inline] __bpf_prog_run include/linux/filter.h:701 [inline] bpf_prog_run include/linux/filter.h:708 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2371 [inline] bpf_trace_run2+0x2ec/0x540 kernel/trace/bpf_trace.c:2412 __bpf_trace_contention_end+0x170/0x230 include/trace/events/lock.h:122 __do_trace_contention_end include/trace/events/lock.h:122 [inline] trace_contention_end+0x118/0x140 include/trace/events/lock.h:122 __pv_queued_spin_lock_slowpath+0xb7e/0xdb0 kernel/locking/qspinlock.c:557 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:577 [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 trie_delete_elem+0x96/0x6d0 kernel/bpf/lpm_trie.c:470 bpf_prog_5186c38a4019a4cb+0x4b/0x4f bpf_dispatcher_nop_func include/linux/bpf.h:1290 [inline] __bpf_prog_run include/linux/filter.h:701 [inline] bpf_prog_run include/linux/filter.h:708 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2371 [inline] bpf_trace_run4+0x334/0x590 kernel/trace/bpf_trace.c:2414 __bpf_trace_sched_switch+0x294/0x3d0 include/trace/events/sched.h:222 __traceiter_sched_switch+0x98/0xd0 include/trace/events/sched.h:222 __do_trace_sched_switch include/trace/events/sched.h:222 [inline] trace_sched_switch include/trace/events/sched.h:222 [inline] __schedule+0x23ad/0x4c90 kernel/sched/core.c:6762 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:7087 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_acquire+0x264/0x550 kernel/locking/lockdep.c:5855 Code: 2b 00 74 08 4c 89 f7 e8 3a 45 8c 00 f6 44 24 61 02 0f 85 85 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25 RSP: 0018:ffffc900045e7ac0 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff920008bcf64 RCX: ffff88802fc046e8 RDX: dffffc0000000000 RSI: ffffffff8c2ab6a0 RDI: ffffffff8c80ee80 RBP: ffffc900045e7c08 R08: ffffffff94547847 R09: 1ffffffff28a8f08 R10: dffffc0000000000 R11: fffffbfff28a8f09 R12: 1ffff920008bcf60 R13: dffffc0000000000 R14: ffffc900045e7b20 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:337 [inline] rcu_read_lock include/linux/rcupdate.h:849 [inline] get_mem_cgroup_from_objcg+0x3a/0x1d0 include/linux/memcontrol.h:498 obj_cgroup_uncharge_pages+0x85/0x210 mm/memcontrol.c:2611 __memcg_kmem_uncharge_page+0xe9/0x290 mm/memcontrol.c:2689 memcg_kmem_uncharge_page include/linux/memcontrol.h:1711 [inline] exit_task_stack_account+0x11a/0x340 kernel/fork.c:567 do_exit+0x1cfd/0x28e0 kernel/exit.c:979 __do_sys_exit kernel/exit.c:1054 [inline] __se_sys_exit kernel/exit.c:1052 [inline] __x64_sys_exit+0x40/0x40 kernel/exit.c:1052 x64_sys_call+0x2696/0x26b0 arch/x86/include/generated/asm/syscalls_64.h:61 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: 0033:0x7f463858d169 Code: Unable to access opcode bytes at 0x7f463858d13f. RSP: 002b:00007f46393b4fe8 EFLAGS: 00000246 ORIG_RAX: 000000000000003c RAX: ffffffffffffffda RBX: 00007f46387a6080 RCX: 00007f463858d169 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f463860e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f46387a6080 R15: 00007ffeffa84e18 ---------------- Code disassembly (best guess): 0: 2b 00 sub (%rax),%eax 2: 74 08 je 0xc 4: 4c 89 f7 mov %r14,%rdi 7: e8 3a 45 8c 00 call 0x8c4546 c: f6 44 24 61 02 testb $0x2,0x61(%rsp) 11: 0f 85 85 01 00 00 jne 0x19c 17: 41 f7 c7 00 02 00 00 test $0x200,%r15d 1e: 74 01 je 0x21 20: fb sti 21: 48 c7 44 24 40 0e 36 movq $0x45e0360e,0x40(%rsp) 28: e0 45 * 2a: 4b c7 44 25 00 00 00 movq $0x0,0x0(%r13,%r12,1) <-- trapping instruction 31: 00 00 33: 43 c7 44 25 09 00 00 movl $0x0,0x9(%r13,%r12,1) 3a: 00 00 3c: 43 rex.XB 3d: c7 .byte 0xc7 3e: 44 rex.R 3f: 25 .byte 0x25