sit0: entered promiscuous mode ============================================ WARNING: possible recursive locking detected 6.14.0-syzkaller-ga27a97f71394 #0 Not tainted -------------------------------------------- syz.0.953/9013 is trying to acquire lock: ffffc9001a4550d8 (&rb->spinlock){-.-.}-{2:2}, at: __bpf_ringbuf_reserve+0x20e/0x650 kernel/bpf/ringbuf.c:423 but task is already holding lock: ffffc9001a4690d8 (&rb->spinlock){-.-.}-{2:2}, at: __bpf_ringbuf_reserve+0x20e/0x650 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 5 locks held by syz.0.953/9013: #0: ffffffff900fc848 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff900fc848 (rtnl_mutex){+.+.}-{4:4}, at: dev_ioctl+0x806/0x1380 net/core/dev_ioctl.c:820 #1: ffffffff8ed3dfe0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #1: ffffffff8ed3dfe0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #1: ffffffff8ed3dfe0 (rcu_read_lock){....}-{1:3}, at: __inet_dev_addr_type+0x1a1/0x510 net/ipv4/fib_frontend.c:220 #2: ffffffff8ed3dfe0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #2: ffffffff8ed3dfe0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #2: ffffffff8ed3dfe0 (rcu_read_lock){....}-{1:3}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2362 [inline] #2: ffffffff8ed3dfe0 (rcu_read_lock){....}-{1:3}, at: bpf_trace_run4+0x246/0x5a0 kernel/trace/bpf_trace.c:2406 #3: ffffc9001a4690d8 (&rb->spinlock){-.-.}-{2:2}, at: __bpf_ringbuf_reserve+0x20e/0x650 kernel/bpf/ringbuf.c:423 #4: ffffffff8ed3dfe0 (rcu_read_lock){....}-{1:3}, at: trace_call_bpf+0xb9/0x8a0 kernel/trace/bpf_trace.c:-1 stack backtrace: CPU: 1 UID: 0 PID: 9013 Comm: syz.0.953 Not tainted 6.14.0-syzkaller-ga27a97f71394 #0 PREEMPT(full) 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+0x2be/0x2d0 kernel/locking/lockdep.c:3042 check_deadlock kernel/locking/lockdep.c:3094 [inline] validate_chain+0x928/0x24e0 kernel/locking/lockdep.c:3896 __lock_acquire+0xad5/0xd80 kernel/locking/lockdep.c:5235 lock_acquire+0x116/0x2f0 kernel/locking/lockdep.c:5866 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd8/0x130 kernel/locking/spinlock.c:162 __bpf_ringbuf_reserve+0x20e/0x650 kernel/bpf/ringbuf.c:423 ____bpf_ringbuf_output kernel/bpf/ringbuf.c:549 [inline] bpf_ringbuf_output+0x67/0x1e0 kernel/bpf/ringbuf.c:539 bpf_prog_4aaef4562453526c+0x43/0x47 bpf_dispatcher_nop_func include/linux/bpf.h:1316 [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:2215 [inline] trace_call_bpf+0x36a/0x8a0 kernel/trace/bpf_trace.c:146 perf_trace_run_bpf_submit+0x82/0x180 kernel/events/core.c:10807 do_perf_trace_lock include/trace/events/lock.h:50 [inline] perf_trace_lock+0x39c/0x4a0 include/trace/events/lock.h:50 __do_trace_lock_release include/trace/events/lock.h:69 [inline] trace_lock_release include/trace/events/lock.h:69 [inline] lock_release+0x3b4/0x3e0 kernel/locking/lockdep.c:5877 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:149 [inline] _raw_spin_unlock_irqrestore+0x7a/0x140 kernel/locking/spinlock.c:194 __bpf_ringbuf_reserve+0x4c5/0x650 kernel/bpf/ringbuf.c:461 ____bpf_ringbuf_output kernel/bpf/ringbuf.c:549 [inline] bpf_ringbuf_output+0x67/0x1e0 kernel/bpf/ringbuf.c:539 bpf_prog_6a3151ed51c78ee7+0x4c/0x50 bpf_dispatcher_nop_func include/linux/bpf.h:1316 [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:2363 [inline] bpf_trace_run4+0x336/0x5a0 kernel/trace/bpf_trace.c:2406 __bpf_trace_fib_table_lookup+0x2a2/0x3e0 include/trace/events/fib.h:13 __do_trace_fib_table_lookup include/trace/events/fib.h:13 [inline] trace_fib_table_lookup+0x1ca/0x230 include/trace/events/fib.h:13 fib_table_lookup+0x1325/0x1880 net/ipv4/fib_trie.c:-1 __inet_dev_addr_type+0x328/0x510 net/ipv4/fib_frontend.c:225 fib_valid_prefsrc+0xf7/0x1d0 net/ipv4/fib_semantics.c:1340 fib_create_info+0x1cd7/0x2cc0 net/ipv4/fib_semantics.c:1520 fib_table_insert+0x14b/0x1d70 net/ipv4/fib_trie.c:1212 fib_magic+0x3da/0x620 net/ipv4/fib_frontend.c:1133 fib_add_ifaddr+0x398/0x5e0 net/ipv4/fib_frontend.c:1170 fib_netdev_event+0x375/0x490 net/ipv4/fib_frontend.c:1515 notifier_call_chain+0x1a5/0x3f0 kernel/notifier.c:85 __dev_notify_flags+0x209/0x410 net/core/dev.c:-1 netif_change_flags+0xf0/0x1a0 net/core/dev.c:9438 dev_change_flags+0x146/0x270 net/core/dev_api.c:68 dev_ioctl+0x819/0x1380 net/core/dev_ioctl.c:821 sock_do_ioctl+0x233/0x490 net/socket.c:1204 sock_ioctl+0x644/0x900 net/socket.c:1311 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f936698d169 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f93677dc038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f9366ba6080 RCX: 00007f936698d169 RDX: 0000200000000040 RSI: 0000000000008914 RDI: 000000000000000f RBP: 00007f9366a0e990 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f9366ba6080 R15: 00007ffd1d871e48