============================================ WARNING: possible recursive locking detected 6.9.0-rc5-syzkaller-00192-g8953285d7bd6 #0 Not tainted -------------------------------------------- syz-executor.3/11550 is trying to acquire lock: ffff888057abf1d8 (&qs->lock){-.-.}-{2:2}, at: queue_stack_map_push_elem+0x1b2/0x660 kernel/bpf/queue_stack_maps.c:210 but task is already holding lock: ffff8880596491d8 (&qs->lock){-.-.}-{2:2}, at: queue_stack_map_push_elem+0x1b2/0x660 kernel/bpf/queue_stack_maps.c:210 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&qs->lock); lock(&qs->lock); *** DEADLOCK *** May be due to missing lock nesting notation 8 locks held by syz-executor.3/11550: #0: ffff88806caf1e20 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_lock include/linux/mmap_lock.h:146 [inline] #0: ffff88806caf1e20 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x1be/0xd60 mm/mmap.c:3251 #1: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #1: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #1: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: __pte_offset_map+0x82/0x380 mm/pgtable-generic.c:285 #2: ffff8880293f9798 (ptlock_ptr(ptdesc)#2){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] #2: ffff8880293f9798 (ptlock_ptr(ptdesc)#2){+.+.}-{2:2}, at: __pte_offset_map_lock+0x1ba/0x300 mm/pgtable-generic.c:373 #3: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #3: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #3: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: page_ext_get+0x20/0x2a0 mm/page_ext.c:508 #4: ffffffff8e334de0 (rcu_callback){....}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #4: ffffffff8e334de0 (rcu_callback){....}-{0:0}, at: rcu_do_batch kernel/rcu/tree.c:2190 [inline] #4: ffffffff8e334de0 (rcu_callback){....}-{0:0}, at: rcu_core+0xa86/0x1830 kernel/rcu/tree.c:2471 #5: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #5: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #5: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2380 [inline] #5: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run3+0x14a/0x460 kernel/trace/bpf_trace.c:2421 #6: ffff8880596491d8 (&qs->lock){-.-.}-{2:2}, at: queue_stack_map_push_elem+0x1b2/0x660 kernel/bpf/queue_stack_maps.c:210 #7: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #7: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #7: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2380 [inline] #7: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x114/0x420 kernel/trace/bpf_trace.c:2420 stack backtrace: CPU: 1 PID: 11550 Comm: syz-executor.3 Not tainted 6.9.0-rc5-syzkaller-00192-g8953285d7bd6 #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+0x241/0x360 lib/dump_stack.c:114 check_deadlock kernel/locking/lockdep.c:3062 [inline] validate_chain+0x15c1/0x58e0 kernel/locking/lockdep.c:3856 __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 queue_stack_map_push_elem+0x1b2/0x660 kernel/bpf/queue_stack_maps.c:210 bpf_prog_216c997a1f42e404+0x3f/0x43 bpf_dispatcher_nop_func include/linux/bpf.h:1234 [inline] __bpf_prog_run include/linux/filter.h:657 [inline] bpf_prog_run include/linux/filter.h:664 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2381 [inline] bpf_trace_run2+0x204/0x420 kernel/trace/bpf_trace.c:2420 trace_contention_end+0x114/0x140 include/trace/events/lock.h:122 __pv_queued_spin_lock_slowpath+0x939/0xc60 kernel/locking/qspinlock.c:560 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 queue_stack_map_push_elem+0x1b2/0x660 kernel/bpf/queue_stack_maps.c:210 bpf_prog_216c997a1f42e404+0x3f/0x43 bpf_dispatcher_nop_func include/linux/bpf.h:1234 [inline] __bpf_prog_run include/linux/filter.h:657 [inline] bpf_prog_run include/linux/filter.h:664 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2381 [inline] bpf_trace_run3+0x238/0x460 kernel/trace/bpf_trace.c:2421 __traceiter_kmem_cache_free+0x33/0x50 include/trace/events/kmem.h:114 trace_kmem_cache_free include/trace/events/kmem.h:114 [inline] kmem_cache_free+0x25a/0x2c0 mm/slub.c:4343 rcu_do_batch kernel/rcu/tree.c:2196 [inline] rcu_core+0xafd/0x1830 kernel/rcu/tree.c:2471 __do_softirq+0x2c6/0x980 kernel/softirq.c:554 invoke_softirq kernel/softirq.c:428 [inline] __irq_exit_rcu+0xf2/0x1c0 kernel/softirq.c:633 irq_exit_rcu+0x9/0x30 kernel/softirq.c:645 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1043 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_acquire+0x264/0x550 kernel/locking/lockdep.c:5758 Code: 2b 00 74 08 4c 89 f7 e8 9a f1 87 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:ffffc90013477140 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff9200268ee34 RCX: 0000000000000001 RDX: dffffc0000000000 RSI: ffffffff8bcaca20 RDI: ffffffff8c1f96e0 RBP: ffffc90013477290 R08: ffffffff92f35507 R09: 1ffffffff25e6aa0 R10: dffffc0000000000 R11: fffffbfff25e6aa1 R12: 1ffff9200268ee30 R13: dffffc0000000000 R14: ffffc900134771a0 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:329 [inline] rcu_read_lock include/linux/rcupdate.h:781 [inline] page_ext_get+0x3d/0x2a0 mm/page_ext.c:508 page_table_check_clear+0x59/0x730 mm/page_table_check.c:72 get_and_clear_full_ptes include/linux/pgtable.h:634 [inline] zap_present_folio_ptes mm/memory.c:1479 [inline] zap_present_ptes mm/memory.c:1563 [inline] zap_pte_range mm/memory.c:1605 [inline] zap_pmd_range mm/memory.c:1722 [inline] zap_pud_range mm/memory.c:1751 [inline] zap_p4d_range mm/memory.c:1772 [inline] unmap_page_range+0x31b0/0x4820 mm/memory.c:1793 unmap_vmas+0x3cc/0x5f0 mm/memory.c:1883 exit_mmap+0x2cb/0xd60 mm/mmap.c:3267 __mmput+0x115/0x3c0 kernel/fork.c:1346 exit_mm+0x220/0x310 kernel/exit.c:569 do_exit+0x99e/0x27e0 kernel/exit.c:865 do_group_exit+0x207/0x2c0 kernel/exit.c:1027 get_signal+0x16a1/0x1740 kernel/signal.c:2911 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xc9/0x370 kernel/entry/common.c:218 do_syscall_64+0x102/0x240 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f6e6ea7dea9 Code: Unable to access opcode bytes at 0x7f6e6ea7de7f. RSP: 002b:00007f6e6f738178 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: 0000000000000000 RBX: 00007f6e6ebac058 RCX: 00007f6e6ea7dea9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f6e6ebac058 RBP: 00007f6e6ebac050 R08: 00007f6e6f7386c0 R09: 00007f6e6f7386c0 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f6e6ebac05c R13: 000000000000006e R14: 00007ffe58b5fd00 R15: 00007ffe58b5fde8 ---------------- Code disassembly (best guess): 0: 2b 00 sub (%rax),%eax 2: 74 08 je 0xc 4: 4c 89 f7 mov %r14,%rdi 7: e8 9a f1 87 00 call 0x87f1a6 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