============================================ WARNING: possible recursive locking detected syzkaller #0 Not tainted -------------------------------------------- modprobe/6447 is trying to acquire lock: ffffc900033690d8 (&rb->spinlock){-.-.}-{2:2}, at: __bpf_ringbuf_reserve+0x1c7/0x5a0 kernel/bpf/ringbuf.c:423 but task is already holding lock: ffffc90003cb90d8 (&rb->spinlock){-.-.}-{2:2}, at: __bpf_ringbuf_reserve+0x1c7/0x5a0 kernel/bpf/ringbuf.c:423 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 4 locks held by modprobe/6447: #0: ffff8880160737a0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:415 [inline] #0: ffff8880160737a0 (&mm->mmap_lock){++++}-{4:4}, at: setup_arg_pages+0x2b3/0xaa0 fs/exec.c:650 #1: ffffffff8aede9a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #1: ffffffff8aede9a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #1: ffffffff8aede9a0 (rcu_read_lock){....}-{1:3}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2256 [inline] #1: ffffffff8aede9a0 (rcu_read_lock){....}-{1:3}, at: bpf_trace_run2+0x186/0x4b0 kernel/trace/bpf_trace.c:2298 #2: ffffc90003cb90d8 (&rb->spinlock){-.-.}-{2:2}, at: __bpf_ringbuf_reserve+0x1c7/0x5a0 kernel/bpf/ringbuf.c:423 #3: ffffffff8aede9a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #3: ffffffff8aede9a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #3: ffffffff8aede9a0 (rcu_read_lock){....}-{1:3}, at: trace_call_bpf+0xb7/0x850 kernel/trace/bpf_trace.c:-1 stack backtrace: CPU: 1 UID: 0 PID: 6447 Comm: modprobe Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_deadlock_bug+0x28b/0x2a0 kernel/locking/lockdep.c:3041 check_deadlock kernel/locking/lockdep.c:3093 [inline] validate_chain+0x1a3f/0x2140 kernel/locking/lockdep.c:3895 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xa7/0xf0 kernel/locking/spinlock.c:162 __bpf_ringbuf_reserve+0x1c7/0x5a0 kernel/bpf/ringbuf.c:423 ____bpf_ringbuf_reserve kernel/bpf/ringbuf.c:474 [inline] bpf_ringbuf_reserve+0x5c/0x70 kernel/bpf/ringbuf.c:466 ___bpf_prog_run+0xf58/0xb2b0 kernel/bpf/core.c:2032 __bpf_prog_run32+0xdb/0x130 kernel/bpf/core.c:2326 bpf_dispatcher_nop_func include/linux/bpf.h:1332 [inline] __bpf_prog_run include/linux/filter.h:718 [inline] bpf_prog_run include/linux/filter.h:725 [inline] bpf_prog_run_array include/linux/bpf.h:2292 [inline] trace_call_bpf+0x326/0x850 kernel/trace/bpf_trace.c:146 perf_trace_run_bpf_submit+0x78/0x170 kernel/events/core.c:10911 do_perf_trace_contention_end include/trace/events/lock.h:122 [inline] perf_trace_contention_end+0x253/0x2f0 include/trace/events/lock.h:122 __do_trace_contention_end include/trace/events/lock.h:122 [inline] trace_contention_end+0x111/0x140 include/trace/events/lock.h:122 __pv_queued_spin_lock_slowpath+0x9f9/0xb60 kernel/locking/qspinlock.c:374 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:557 [inline] queued_spin_lock_slowpath+0x43/0x50 arch/x86/include/asm/qspinlock.h:51 queued_spin_lock include/asm-generic/qspinlock.h:114 [inline] do_raw_spin_lock+0x21f/0x290 kernel/locking/spinlock_debug.c:116 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline] _raw_spin_lock_irqsave+0xb3/0xf0 kernel/locking/spinlock.c:162 __bpf_ringbuf_reserve+0x1c7/0x5a0 kernel/bpf/ringbuf.c:423 ____bpf_ringbuf_reserve kernel/bpf/ringbuf.c:474 [inline] bpf_ringbuf_reserve+0x5c/0x70 kernel/bpf/ringbuf.c:466 ___bpf_prog_run+0xf58/0xb2b0 kernel/bpf/core.c:2032 __bpf_prog_run32+0xdb/0x130 kernel/bpf/core.c:2326 bpf_dispatcher_nop_func include/linux/bpf.h:1332 [inline] __bpf_prog_run include/linux/filter.h:718 [inline] bpf_prog_run include/linux/filter.h:725 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2257 [inline] bpf_trace_run2+0x281/0x4b0 kernel/trace/bpf_trace.c:2298 __bpf_trace_tlb_flush+0xf5/0x150 include/trace/events/tlb.h:38 __do_trace_tlb_flush include/trace/events/tlb.h:38 [inline] trace_tlb_flush+0x115/0x140 include/trace/events/tlb.h:38 flush_tlb_func+0x5b9/0x6c0 arch/x86/mm/tlb.c:1270 flush_tlb_mm_range+0xbac/0x12d0 arch/x86/mm/tlb.c:1456 tlb_flush arch/x86/include/asm/tlb.h:23 [inline] tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:490 [inline] tlb_flush_mmu+0x1a7/0x680 mm/mmu_gather.c:403 tlb_finish_mmu+0xc3/0x1d0 mm/mmu_gather.c:497 relocate_vma_down+0x4b4/0x500 mm/vma_exec.c:87 setup_arg_pages+0x5df/0xaa0 fs/exec.c:690 load_elf_binary+0xba4/0x2790 fs/binfmt_elf.c:1013 search_binary_handler fs/exec.c:1670 [inline] exec_binprm fs/exec.c:1702 [inline] bprm_execve+0x97a/0x13d0 fs/exec.c:1754 kernel_execve+0x8f0/0x9f0 fs/exec.c:1920 call_usermodehelper_exec_async+0x20b/0x360 kernel/umh.c:109 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 modprobe (6447) used greatest stack depth: 20840 bytes left