============================================ WARNING: possible recursive locking detected syzkaller #0 Not tainted -------------------------------------------- syz.2.9806/12743 is trying to acquire lock: ffff88807bd4af70 (&hsr->seqnr_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] ffff88807bd4af70 (&hsr->seqnr_lock){+.-.}-{3:3}, at: hsr_dev_xmit+0x237/0x360 net/hsr/hsr_device.c:235 but task is already holding lock: ffff88805d564f70 (&hsr->seqnr_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] ffff88805d564f70 (&hsr->seqnr_lock){+.-.}-{3:3}, at: hsr_dev_xmit+0x237/0x360 net/hsr/hsr_device.c:235 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&hsr->seqnr_lock); lock(&hsr->seqnr_lock); *** DEADLOCK *** May be due to missing lock nesting notation 16 locks held by syz.2.9806/12743: #0: ffffffff8f99d690 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x4f7/0x730 net/core/net_namespace.c:577 #1: ffffffff8f7058d0 (devices_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x200/0x2f0 drivers/infiniband/core/device.c:1215 #2: ffffffff8f705a90 (rdma_nets_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x238/0x2f0 drivers/infiniband/core/device.c:1220 #3: ffff88806661cf98 (&device->compat_devs_mutex){+.+.}-{4:4}, at: add_one_compat_dev+0xf0/0x650 drivers/infiniband/core/device.c:979 #4: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #4: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #4: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1195 [inline] #4: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0xa5/0x23c0 arch/x86/kernel/unwind_orc.c:495 #5: ffffc90000007ce0 ((&ndev->rs_timer)){+.-.}-{0:0}, at: call_timer_fn+0xd4/0x5a0 kernel/time/timer.c:1745 #6: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #6: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #6: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: ndisc_send_skb+0x1fd/0x14e0 net/ipv6/ndisc.c:482 #7: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #7: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #7: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: ip6_output+0x126/0x550 net/ipv6/ip6_output.c:234 #8: ffffffff8e55a3c0 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #8: ffffffff8e55a3c0 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:918 [inline] #8: ffffffff8e55a3c0 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x274/0x3850 net/core/dev.c:4754 #9: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #9: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #9: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: hsr_dev_xmit+0x2d/0x360 net/hsr/hsr_device.c:229 #10: ffff88805d564f70 (&hsr->seqnr_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] #10: ffff88805d564f70 (&hsr->seqnr_lock){+.-.}-{3:3}, at: hsr_dev_xmit+0x237/0x360 net/hsr/hsr_device.c:235 #11: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #11: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #11: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: hsr_forward_skb+0xb3/0x2860 net/hsr/hsr_forward.c:738 #12: ffffffff8e55a3c0 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #12: ffffffff8e55a3c0 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:918 [inline] #12: ffffffff8e55a3c0 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x274/0x3850 net/core/dev.c:4754 #13: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #13: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #13: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: br_dev_xmit+0x193/0x1920 net/bridge/br_device.c:52 #14: ffffffff8e55a3c0 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #14: ffffffff8e55a3c0 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:918 [inline] #14: ffffffff8e55a3c0 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x274/0x3850 net/core/dev.c:4754 #15: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #15: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #15: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: hsr_dev_xmit+0x2d/0x360 net/hsr/hsr_device.c:229 stack backtrace: CPU: 0 UID: 0 PID: 12743 Comm: syz.2.9806 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_deadlock_bug+0x279/0x290 kernel/locking/lockdep.c:3041 check_deadlock kernel/locking/lockdep.c:3093 [inline] validate_chain kernel/locking/lockdep.c:3895 [inline] __lock_acquire+0x253f/0x2cf0 kernel/locking/lockdep.c:5237 lock_acquire+0x106/0x330 kernel/locking/lockdep.c:5868 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x36/0x50 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] hsr_dev_xmit+0x237/0x360 net/hsr/hsr_device.c:235 __netdev_start_xmit include/linux/netdevice.h:5275 [inline] netdev_start_xmit include/linux/netdevice.h:5284 [inline] xmit_one net/core/dev.c:3864 [inline] dev_hard_start_xmit+0x2cd/0x7f0 net/core/dev.c:3880 __dev_queue_xmit+0x168f/0x3850 net/core/dev.c:4829 dev_queue_xmit include/linux/netdevice.h:3384 [inline] br_dev_queue_push_xmit+0x370/0x4a0 net/bridge/br_forward.c:53 NF_HOOK+0x360/0x3f0 include/linux/netfilter.h:318 br_forward_finish+0xd3/0x130 net/bridge/br_forward.c:66 NF_HOOK+0x360/0x3f0 include/linux/netfilter.h:318 __br_forward+0x397/0x540 net/bridge/br_forward.c:115 deliver_clone net/bridge/br_forward.c:131 [inline] maybe_deliver net/bridge/br_forward.c:191 [inline] br_flood+0x6ee/0xb80 net/bridge/br_forward.c:238 br_dev_xmit+0x127a/0x1920 net/bridge/br_device.c:108 __netdev_start_xmit include/linux/netdevice.h:5275 [inline] netdev_start_xmit include/linux/netdevice.h:5284 [inline] xmit_one net/core/dev.c:3864 [inline] dev_hard_start_xmit+0x2cd/0x7f0 net/core/dev.c:3880 __dev_queue_xmit+0x168f/0x3850 net/core/dev.c:4829 dev_queue_xmit include/linux/netdevice.h:3384 [inline] hsr_xmit net/hsr/hsr_forward.c:440 [inline] hsr_forward_do net/hsr/hsr_forward.c:581 [inline] hsr_forward_skb+0x157b/0x2860 net/hsr/hsr_forward.c:743 hsr_dev_xmit+0x242/0x360 net/hsr/hsr_device.c:236 __netdev_start_xmit include/linux/netdevice.h:5275 [inline] netdev_start_xmit include/linux/netdevice.h:5284 [inline] xmit_one net/core/dev.c:3864 [inline] dev_hard_start_xmit+0x2cd/0x7f0 net/core/dev.c:3880 __dev_queue_xmit+0x168f/0x3850 net/core/dev.c:4829 NF_HOOK_COND include/linux/netfilter.h:307 [inline] ip6_output+0x340/0x550 net/ipv6/ip6_output.c:246 NF_HOOK include/linux/netfilter.h:318 [inline] ndisc_send_skb+0xbaa/0x14e0 net/ipv6/ndisc.c:512 addrconf_rs_timer+0x395/0x6d0 net/ipv6/addrconf.c:4042 call_timer_fn+0x192/0x5a0 kernel/time/timer.c:1748 expire_timers kernel/time/timer.c:1799 [inline] __run_timers kernel/time/timer.c:2373 [inline] __run_timer_base+0x652/0x8b0 kernel/time/timer.c:2385 run_timer_base kernel/time/timer.c:2394 [inline] run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2404 handle_softirqs+0x22a/0x7c0 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x5f/0x150 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:unwind_next_frame+0x199/0x23c0 arch/x86/kernel/unwind_orc.c:510 Code: 04 28 84 c0 0f 85 45 1b 00 00 4c 89 6c 24 48 4c 89 64 24 20 4c 89 7c 24 50 48 89 5c 24 18 0f b6 1b 48 8b 44 24 30 80 3c 28 00 <4c> 8b 7c 24 10 74 08 4c 89 ff e8 c8 34 b7 00 4d 8b 27 48 83 f3 01 RSP: 0018:ffffc9000bbd6f18 EFLAGS: 00000246 RAX: 1ffff9200177ae06 RBX: 0000000000000000 RCX: 0000000080000001 RDX: 000000001232cfad RSI: ffffffff8c0739e0 RDI: ffffffff8c0739a0 RBP: dffffc0000000000 R08: ffffffff81757195 R09: ffffffff8e55a360 R10: ffffc9000bbd7038 R11: ffffffff81af9170 R12: 1ffff9200177adfd R13: ffffc9000bbd7038 R14: ffffc9000bbd6fe8 R15: ffffffff81757195 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5657 [inline] __kmalloc_node_track_caller_noprof+0x558/0x7f0 mm/slub.c:5768 __kmemdup_nul mm/util.c:64 [inline] kstrdup+0x42/0x100 mm/util.c:84 __kernfs_new_node+0xa9/0x8e0 fs/kernfs/dir.c:633 kernfs_new_node+0x102/0x210 fs/kernfs/dir.c:718 __kernfs_create_file+0x4b/0x2e0 fs/kernfs/file.c:1057 sysfs_add_file_mode_ns+0x238/0x300 fs/sysfs/file.c:313 create_files fs/sysfs/group.c:82 [inline] internal_create_group+0x673/0x1180 fs/sysfs/group.c:189 internal_create_groups fs/sysfs/group.c:229 [inline] sysfs_create_groups+0x59/0x120 fs/sysfs/group.c:255 setup_port drivers/infiniband/core/sysfs.c:1247 [inline] ib_setup_port_attrs+0xe1b/0x2140 drivers/infiniband/core/sysfs.c:1433 add_one_compat_dev+0x448/0x650 drivers/infiniband/core/device.c:1005 rdma_dev_init_net+0x243/0x2f0 drivers/infiniband/core/device.c:1221 ops_init+0x35c/0x5c0 net/core/net_namespace.c:137 setup_net+0x118/0x340 net/core/net_namespace.c:446 copy_net_ns+0x50e/0x730 net/core/net_namespace.c:581 create_new_namespaces+0x3e7/0x6a0 kernel/nsproxy.c:130 unshare_nsproxy_namespaces+0x11a/0x160 kernel/nsproxy.c:226 ksys_unshare+0x4f4/0x900 kernel/fork.c:3171 __do_sys_unshare kernel/fork.c:3242 [inline] __se_sys_unshare kernel/fork.c:3240 [inline] __x64_sys_unshare+0x38/0x50 kernel/fork.c:3240 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f551339aeb9 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f5514202028 EFLAGS: 00000246 ORIG_RAX: 0000000000000110 RAX: ffffffffffffffda RBX: 00007f5513615fa0 RCX: 00007f551339aeb9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000006a040000 RBP: 00007f5513408c1f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f5513616038 R14: 00007f5513615fa0 R15: 00007fffccd07618 ---------------- Code disassembly (best guess): 0: 04 28 add $0x28,%al 2: 84 c0 test %al,%al 4: 0f 85 45 1b 00 00 jne 0x1b4f a: 4c 89 6c 24 48 mov %r13,0x48(%rsp) f: 4c 89 64 24 20 mov %r12,0x20(%rsp) 14: 4c 89 7c 24 50 mov %r15,0x50(%rsp) 19: 48 89 5c 24 18 mov %rbx,0x18(%rsp) 1e: 0f b6 1b movzbl (%rbx),%ebx 21: 48 8b 44 24 30 mov 0x30(%rsp),%rax 26: 80 3c 28 00 cmpb $0x0,(%rax,%rbp,1) * 2a: 4c 8b 7c 24 10 mov 0x10(%rsp),%r15 <-- trapping instruction 2f: 74 08 je 0x39 31: 4c 89 ff mov %r15,%rdi 34: e8 c8 34 b7 00 call 0xb73501 39: 4d 8b 27 mov (%r15),%r12 3c: 48 83 f3 01 xor $0x1,%rbx