============================================ WARNING: possible recursive locking detected syzkaller #0 Not tainted -------------------------------------------- modprobe/12550 is trying to acquire lock: ffffc9000f8290d8 (&rb->spinlock){-.-.}-{2:2}, at: __bpf_ringbuf_reserve+0x1c8/0x5a0 kernel/bpf/ringbuf.c:425 but task is already holding lock: ffffc9000c6ea0d8 (&rb->spinlock){-.-.}-{2:2}, at: __bpf_ringbuf_reserve+0x1c8/0x5a0 kernel/bpf/ringbuf.c:425 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&rb->spinlock); lock(&rb->spinlock); *** DEADLOCK *** May be due to missing lock nesting notation 6 locks held by modprobe/12550: #0: ffff88802d24b120 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:124 [inline] #0: ffff88802d24b120 (&mm->mmap_lock){++++}-{3:3}, at: vm_mmap_pgoff+0x168/0x400 mm/util.c:554 #1: ffff888030cd1f58 (&anon_vma->rwsem){++++}-{3:3}, at: anon_vma_lock_read include/linux/rmap.h:131 [inline] #1: ffff888030cd1f58 (&anon_vma->rwsem){++++}-{3:3}, at: validate_mm+0x1a8/0x420 mm/mmap.c:316 #2: ffff8880b8f3c018 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:558 #3: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #3: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #3: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2321 [inline] #3: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run4+0xfd/0x420 kernel/trace/bpf_trace.c:2363 #4: ffffc9000c6ea0d8 (&rb->spinlock){-.-.}-{2:2}, at: __bpf_ringbuf_reserve+0x1c8/0x5a0 kernel/bpf/ringbuf.c:425 #5: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #5: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #5: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: trace_call_bpf+0xc3/0x690 kernel/trace/bpf_trace.c:142 stack backtrace: CPU: 1 PID: 12550 Comm: modprobe Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106 check_deadlock kernel/locking/lockdep.c:3062 [inline] validate_chain kernel/locking/lockdep.c:3856 [inline] __lock_acquire+0x5d40/0x7c80 kernel/locking/lockdep.c:5137 lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xa8/0xf0 kernel/locking/spinlock.c:162 __bpf_ringbuf_reserve+0x1c8/0x5a0 kernel/bpf/ringbuf.c:425 ____bpf_ringbuf_reserve kernel/bpf/ringbuf.c:476 [inline] bpf_ringbuf_reserve+0x5c/0x70 kernel/bpf/ringbuf.c:468 bpf_prog_df2ea1bb7efca089+0x35/0x4f bpf_dispatcher_nop_func include/linux/bpf.h:1224 [inline] __bpf_prog_run include/linux/filter.h:612 [inline] bpf_prog_run include/linux/filter.h:619 [inline] bpf_prog_run_array include/linux/bpf.h:1994 [inline] trace_call_bpf+0x321/0x690 kernel/trace/bpf_trace.c:143 perf_trace_run_bpf_submit+0x7a/0x1c0 kernel/events/core.c:10263 perf_trace_contention_begin+0x254/0x2f0 include/trace/events/lock.h:95 trace_contention_begin+0xe9/0x110 include/trace/events/lock.h:95 __pv_queued_spin_lock_slowpath+0xe0/0x9d0 kernel/locking/qspinlock.c:405 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:586 [inline] queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline] queued_spin_lock include/asm-generic/qspinlock.h:114 [inline] do_raw_spin_lock+0x24e/0x2c0 kernel/locking/spinlock_debug.c:115 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline] _raw_spin_lock_irqsave+0xb4/0xf0 kernel/locking/spinlock.c:162 __bpf_ringbuf_reserve+0x1c8/0x5a0 kernel/bpf/ringbuf.c:425 ____bpf_ringbuf_reserve kernel/bpf/ringbuf.c:476 [inline] bpf_ringbuf_reserve+0x5c/0x70 kernel/bpf/ringbuf.c:468 bpf_prog_f5164495852e6435+0x30/0x4a bpf_dispatcher_nop_func include/linux/bpf.h:1224 [inline] __bpf_prog_run include/linux/filter.h:612 [inline] bpf_prog_run include/linux/filter.h:619 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2322 [inline] bpf_trace_run4+0x1f9/0x420 kernel/trace/bpf_trace.c:2363 __bpf_trace_sched_switch+0x17b/0x1e0 include/trace/events/sched.h:222 __traceiter_sched_switch+0x93/0xc0 include/trace/events/sched.h:222 trace_sched_switch include/trace/events/sched.h:222 [inline] __schedule+0x2197/0x44d0 kernel/sched/core.c:6696 preempt_schedule_notrace+0xce/0x110 kernel/sched/core.c:6959 preempt_schedule_notrace_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:46 trace_lock_release include/trace/events/lock.h:69 [inline] lock_release+0x871/0x8b0 kernel/locking/lockdep.c:5765 up_read+0x16/0x20 kernel/locking/rwsem.c:1615 anon_vma_unlock_read include/linux/rmap.h:141 [inline] validate_mm+0x223/0x420 mm/mmap.c:319 __split_vma+0xa93/0xc00 mm/mmap.c:2425 do_vmi_align_munmap+0x377/0x1660 mm/mmap.c:2514 do_vmi_munmap+0x252/0x2d0 mm/mmap.c:2660 __mmap_region mm/mmap.c:2710 [inline] mmap_region+0x741/0x2020 mm/mmap.c:2941 do_mmap+0x92f/0x10a0 mm/mmap.c:1385 vm_mmap_pgoff+0x1c0/0x400 mm/util.c:556 ksys_mmap_pgoff+0x520/0x700 mm/mmap.c:1431 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fda66cd0242 Code: 08 00 04 00 00 eb e2 90 41 f7 c1 ff 0f 00 00 75 27 55 89 cd 53 48 89 fb 48 85 ff 74 33 41 89 ea 48 89 df b8 09 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 5e 5b 5d c3 0f 1f 00 c7 05 46 40 01 00 16 00 RSP: 002b:00007ffc2bf49718 EFLAGS: 00000206 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007fda66946000 RCX: 00007fda66cd0242 RDX: 0000000000000005 RSI: 0000000000037000 RDI: 00007fda66946000 RBP: 0000000000000812 R08: 0000000000000000 R09: 0000000000003000 R10: 0000000000000812 R11: 0000000000000206 R12: 00007ffc2bf49768 R13: 00007fda669af6b0 R14: 00007ffc2bf49b50 R15: 00000fff857e92e6