============================================ WARNING: possible recursive locking detected syzkaller #0 Not tainted -------------------------------------------- syz.4.13514/26124 is trying to acquire lock: ffff8880636e8f30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] ffff8880636e8f30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: hsr_dev_xmit+0x237/0x360 net/hsr/hsr_device.c:235 but task is already holding lock: ffff88807ddc8f30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] ffff88807ddc8f30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: send_hsr_supervision_frame+0x380/0xcb0 net/hsr/hsr_device.c:330 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 13 locks held by syz.4.13514/26124: #0: ffffffff8f304db0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x3cc/0x570 net/core/net_namespace.c:577 #1: ffffffff8f078d90 (devices_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x1f5/0x2f0 drivers/infiniband/core/device.c:1215 #2: ffffffff8f078f50 (rdma_nets_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x22d/0x2f0 drivers/infiniband/core/device.c:1220 #3: ffff8880798f0f98 (&device->compat_devs_mutex){+.+.}-{4:4}, at: add_one_compat_dev+0xf0/0x650 drivers/infiniband/core/device.c:979 #4: ffffffff8df41aa0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #4: ffffffff8df41aa0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #4: ffffffff8df41aa0 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1195 [inline] #4: ffffffff8df41aa0 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0xa5/0x23d0 arch/x86/kernel/unwind_orc.c:495 #5: ffffc90000007ce0 ((&hsr->announce_timer)){+.-.}-{0:0}, at: call_timer_fn+0xbe/0x590 kernel/time/timer.c:1745 #6: ffffffff8df41aa0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #6: ffffffff8df41aa0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #6: ffffffff8df41aa0 (rcu_read_lock){....}-{1:3}, at: hsr_announce+0x83/0x360 net/hsr/hsr_device.c:419 #7: ffff88807ddc8f30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] #7: ffff88807ddc8f30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: send_hsr_supervision_frame+0x380/0xcb0 net/hsr/hsr_device.c:330 #8: ffffffff8df41aa0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #8: ffffffff8df41aa0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #8: ffffffff8df41aa0 (rcu_read_lock){....}-{1:3}, at: hsr_forward_skb+0x9e/0x2860 net/hsr/hsr_forward.c:738 #9: ffffffff8df41b00 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #9: ffffffff8df41b00 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:918 [inline] #9: ffffffff8df41b00 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x289/0x31c0 net/core/dev.c:4743 #10: ffffffff8df41aa0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #10: ffffffff8df41aa0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #10: ffffffff8df41aa0 (rcu_read_lock){....}-{1:3}, at: br_dev_xmit+0x184/0x1830 net/bridge/br_device.c:52 #11: ffffffff8df41b00 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #11: ffffffff8df41b00 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:918 [inline] #11: ffffffff8df41b00 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x289/0x31c0 net/core/dev.c:4743 #12: ffffffff8df41aa0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #12: ffffffff8df41aa0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #12: ffffffff8df41aa0 (rcu_read_lock){....}-{1:3}, at: hsr_dev_xmit+0x2d/0x360 net/hsr/hsr_device.c:229 stack backtrace: CPU: 0 UID: 0 PID: 26124 Comm: syz.4.13514 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 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+0x2540/0x2cf0 kernel/locking/lockdep.c:5237 lock_acquire+0x107/0x340 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:5273 [inline] netdev_start_xmit include/linux/netdevice.h:5282 [inline] xmit_one net/core/dev.c:3852 [inline] dev_hard_start_xmit+0x2cd/0x800 net/core/dev.c:3868 __dev_queue_xmit+0x149d/0x31c0 net/core/dev.c:4818 dev_queue_xmit include/linux/netdevice.h:3381 [inline] br_dev_queue_push_xmit+0x6c5/0x890 net/bridge/br_forward.c:53 NF_HOOK+0x320/0x3c0 include/linux/netfilter.h:318 br_forward_finish+0xd3/0x130 net/bridge/br_forward.c:66 NF_HOOK+0x320/0x3c0 include/linux/netfilter.h:318 __br_forward+0x397/0x540 net/bridge/br_forward.c:115 br_dev_xmit+0x1198/0x1830 net/bridge/br_device.c:108 __netdev_start_xmit include/linux/netdevice.h:5273 [inline] netdev_start_xmit include/linux/netdevice.h:5282 [inline] xmit_one net/core/dev.c:3852 [inline] dev_hard_start_xmit+0x2cd/0x800 net/core/dev.c:3868 __dev_queue_xmit+0x149d/0x31c0 net/core/dev.c:4818 dev_queue_xmit include/linux/netdevice.h:3381 [inline] hsr_xmit net/hsr/hsr_forward.c:440 [inline] hsr_forward_do net/hsr/hsr_forward.c:581 [inline] hsr_forward_skb+0x158b/0x2860 net/hsr/hsr_forward.c:743 send_hsr_supervision_frame+0x731/0xcb0 net/hsr/hsr_device.c:364 hsr_announce+0x1d5/0x360 net/hsr/hsr_device.c:421 call_timer_fn+0x16e/0x590 kernel/time/timer.c:1748 expire_timers kernel/time/timer.c:1799 [inline] __run_timers kernel/time/timer.c:2373 [inline] __run_timer_base+0x61a/0x860 kernel/time/timer.c:2385 run_timer_base kernel/time/timer.c:2394 [inline] run_timer_softirq+0xb7/0x180 kernel/time/timer.c:2404 handle_softirqs+0x22b/0x7c0 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x60/0x150 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:finish_task_switch+0x242/0x940 kernel/sched/core.c:5114 Code: 0f 84 c2 01 00 00 48 85 db 0f 85 e9 01 00 00 0f 1f 44 00 00 4c 8b 75 d0 4c 89 e7 e8 08 a9 ca 09 e8 b3 10 37 00 fb 4c 8b 65 c0 <49> 8d bc 24 48 16 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0 RSP: 0018:ffffc900045eeaf8 EFLAGS: 00000202 RAX: 0000000000002e43 RBX: 0000000000000000 RCX: 0000000080000001 RDX: 0000000000000006 RSI: ffffffff8d792329 RDI: ffffffff8bc08360 RBP: ffffc900045eeb50 R08: ffffffff8f822377 R09: 1ffffffff1f0446e R10: dffffc0000000000 R11: fffffbfff1f0446f R12: ffff888081011e80 R13: dffffc0000000000 R14: ffff888089da9e80 R15: ffff8880b863b498 context_switch kernel/sched/core.c:5259 [inline] __schedule+0x14a3/0x4fd0 kernel/sched/core.c:6863 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7190 irqentry_exit+0x5e3/0x670 kernel/entry/common.c:216 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:memory_is_nonzero mm/kasan/generic.c:114 [inline] RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:140 [inline] RIP: 0010:memory_is_poisoned mm/kasan/generic.c:172 [inline] RIP: 0010:check_region_inline mm/kasan/generic.c:191 [inline] RIP: 0010:kasan_check_range+0x7d/0x2c0 mm/kasan/generic.c:200 Code: 49 c1 ef 03 49 ba 00 00 00 00 00 fc ff df 4f 8d 1c 17 49 ff c8 4d 89 c1 49 c1 e9 03 48 bb 01 00 00 00 00 fc ff df 4d 8d 34 19 <4d> 89 f4 4d 29 dc 49 83 fc 10 7f 29 4d 85 e4 0f 84 41 01 00 00 4c RSP: 0018:ffffc900045eee80 EFLAGS: 00000a07 RAX: ffffc900045ef001 RBX: dffffc0000000001 RCX: ffffffff81740b6e RDX: 0000000000000001 RSI: 0000000000000010 RDI: ffffc900045ef058 RBP: 0000000000000000 R08: ffffc900045ef067 R09: 1ffff920008bde0c R10: dffffc0000000000 R11: fffff520008bde0b R12: ffffc900045ef058 R13: 1ffff920008bde03 R14: fffff520008bde0d R15: 1ffff920008bde0b __asan_memset+0x22/0x50 mm/kasan/shadow.c:84 unwind_next_frame+0xeae/0x23d0 arch/x86/kernel/unwind_orc.c:607 __unwind_start+0x5b9/0x760 arch/x86/kernel/unwind_orc.c:773 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0xe4/0x150 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x9c/0xe0 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+0x575/0x820 mm/slub.c:5764 __kmemdup_nul mm/util.c:64 [inline] kstrdup+0x42/0x100 mm/util.c:84 __kernfs_new_node+0x9c/0x8a0 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+0x667/0x1170 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_gid_attrs drivers/infiniband/core/sysfs.c:1162 [inline] ib_setup_port_attrs+0x140c/0x2070 drivers/infiniband/core/sysfs.c:1439 add_one_compat_dev+0x449/0x650 drivers/infiniband/core/device.c:1005 rdma_dev_init_net+0x238/0x2f0 drivers/infiniband/core/device.c:1221 ops_init+0x35c/0x5c0 net/core/net_namespace.c:137 setup_net+0x110/0x330 net/core/net_namespace.c:446 copy_net_ns+0x3e3/0x570 net/core/net_namespace.c:581 create_new_namespaces+0x3e7/0x6a0 kernel/nsproxy.c:130 unshare_nsproxy_namespaces+0x11c/0x170 kernel/nsproxy.c:226 ksys_unshare+0x4c8/0x8c0 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+0xec/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f16e7d8f749 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:00007f16e8c5a038 EFLAGS: 00000246 ORIG_RAX: 0000000000000110 RAX: ffffffffffffffda RBX: 00007f16e7fe5fa0 RCX: 00007f16e7d8f749 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000006a040000 RBP: 00007f16e7e13f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f16e7fe6038 R14: 00007f16e7fe5fa0 R15: 00007ffc5a86c708 ---------------- Code disassembly (best guess): 0: 0f 84 c2 01 00 00 je 0x1c8 6: 48 85 db test %rbx,%rbx 9: 0f 85 e9 01 00 00 jne 0x1f8 f: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) 14: 4c 8b 75 d0 mov -0x30(%rbp),%r14 18: 4c 89 e7 mov %r12,%rdi 1b: e8 08 a9 ca 09 call 0x9caa928 20: e8 b3 10 37 00 call 0x3710d8 25: fb sti 26: 4c 8b 65 c0 mov -0x40(%rbp),%r12 * 2a: 49 8d bc 24 48 16 00 lea 0x1648(%r12),%rdi <-- trapping instruction 31: 00 32: 48 89 f8 mov %rdi,%rax 35: 48 c1 e8 03 shr $0x3,%rax 39: 42 0f b6 04 28 movzbl (%rax,%r13,1),%eax 3e: 84 c0 test %al,%al