============================================ WARNING: possible recursive locking detected 6.14.0-syzkaller-13305-g61f96e684edd #0 Not tainted -------------------------------------------- syz.4.242/6950 is trying to acquire lock: ffff888053a66f30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] ffff888053a66f30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: hsr_dev_xmit+0x18a/0x210 net/hsr/hsr_device.c:234 but task is already holding lock: ffff888032ec4f30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] ffff888032ec4f30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: hsr_dev_xmit+0x18a/0x210 net/hsr/hsr_device.c:234 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 15 locks held by syz.4.242/6950: #0: ffffffff900efe90 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x328/0x570 net/core/net_namespace.c:514 #1: ffffffff8fe63b90 (devices_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x19c/0x280 drivers/infiniband/core/device.c:1178 #2: ffffffff8fe63d50 (rdma_nets_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x1ea/0x280 drivers/infiniband/core/device.c:1183 #3: ffff88807e7ecf60 (&device->compat_devs_mutex){+.+.}-{4:4}, at: add_one_compat_dev+0x10d/0x7a0 drivers/infiniband/core/device.c:942 #4: ffff88801bef7148 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_add_one+0x41/0x530 fs/kernfs/dir.c:791 #5: ffffffff8ed3dfe0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #5: ffffffff8ed3dfe0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #5: ffffffff8ed3dfe0 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1155 [inline] #5: ffffffff8ed3dfe0 (rcu_read_lock){....}-{1:3}, at: kernfs_root+0x1c/0x230 fs/kernfs/kernfs-internal.h:73 #6: ffffc90000007bc0 ((&ndev->rs_timer)){+.-.}-{0:0}, at: call_timer_fn+0xc2/0x650 kernel/time/timer.c:1786 #7: ffffffff8ed3dfe0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #7: ffffffff8ed3dfe0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #7: ffffffff8ed3dfe0 (rcu_read_lock){....}-{1:3}, at: ndisc_send_skb+0x1ef/0x1560 net/ipv6/ndisc.c:484 #8: ffffffff8ed3dfe0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #8: ffffffff8ed3dfe0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #8: ffffffff8ed3dfe0 (rcu_read_lock){....}-{1:3}, at: ip6_finish_output2+0x701/0x1750 net/ipv6/ip6_output.c:126 #9: ffffffff8ed3e040 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #9: ffffffff8ed3e040 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:892 [inline] #9: ffffffff8ed3e040 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x2f9/0x3f60 net/core/dev.c:4561 #10: ffff888032ec4f30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] #10: ffff888032ec4f30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: hsr_dev_xmit+0x18a/0x210 net/hsr/hsr_device.c:234 #11: ffffffff8ed3dfe0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #11: ffffffff8ed3dfe0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #11: ffffffff8ed3dfe0 (rcu_read_lock){....}-{1:3}, at: hsr_forward_skb+0xb8/0x2d20 net/hsr/hsr_forward.c:728 #12: ffffffff8ed3e040 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #12: ffffffff8ed3e040 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:892 [inline] #12: ffffffff8ed3e040 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x2f9/0x3f60 net/core/dev.c:4561 #13: ffffffff8ed3dfe0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #13: ffffffff8ed3dfe0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #13: ffffffff8ed3dfe0 (rcu_read_lock){....}-{1:3}, at: br_dev_xmit+0x220/0x1c00 net/bridge/br_device.c:52 #14: ffffffff8ed3e040 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #14: ffffffff8ed3e040 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:892 [inline] #14: ffffffff8ed3e040 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x2f9/0x3f60 net/core/dev.c:4561 stack backtrace: CPU: 0 UID: 0 PID: 6950 Comm: syz.4.242 Not tainted 6.14.0-syzkaller-13305-g61f96e684edd #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_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] hsr_dev_xmit+0x18a/0x210 net/hsr/hsr_device.c:234 __netdev_start_xmit include/linux/netdevice.h:5201 [inline] netdev_start_xmit include/linux/netdevice.h:5210 [inline] xmit_one net/core/dev.c:3783 [inline] dev_hard_start_xmit+0x2d4/0x840 net/core/dev.c:3799 __dev_queue_xmit+0x1b80/0x3f60 net/core/dev.c:4636 dev_queue_xmit include/linux/netdevice.h:3350 [inline] br_dev_queue_push_xmit+0x771/0x950 net/bridge/br_forward.c:53 NF_HOOK+0x3ac/0x460 include/linux/netfilter.h:314 br_forward_finish+0xd8/0x130 net/bridge/br_forward.c:66 NF_HOOK+0x3ac/0x460 include/linux/netfilter.h:314 __br_forward+0x46a/0x640 net/bridge/br_forward.c:115 deliver_clone net/bridge/br_forward.c:131 [inline] maybe_deliver+0xb3/0x150 net/bridge/br_forward.c:190 br_flood+0x2e4/0x680 net/bridge/br_forward.c:237 br_dev_xmit+0x12ac/0x1c00 net/bridge/br_device.c:-1 __netdev_start_xmit include/linux/netdevice.h:5201 [inline] netdev_start_xmit include/linux/netdevice.h:5210 [inline] xmit_one net/core/dev.c:3783 [inline] dev_hard_start_xmit+0x2d4/0x840 net/core/dev.c:3799 __dev_queue_xmit+0x1b80/0x3f60 net/core/dev.c:4636 dev_queue_xmit include/linux/netdevice.h:3350 [inline] hsr_xmit net/hsr/hsr_forward.c:430 [inline] hsr_forward_do net/hsr/hsr_forward.c:571 [inline] hsr_forward_skb+0x184c/0x2d20 net/hsr/hsr_forward.c:733 hsr_dev_xmit+0x195/0x210 net/hsr/hsr_device.c:235 __netdev_start_xmit include/linux/netdevice.h:5201 [inline] netdev_start_xmit include/linux/netdevice.h:5210 [inline] xmit_one net/core/dev.c:3783 [inline] dev_hard_start_xmit+0x2d4/0x840 net/core/dev.c:3799 __dev_queue_xmit+0x1b80/0x3f60 net/core/dev.c:4636 neigh_output include/net/neighbour.h:539 [inline] ip6_finish_output2+0x1296/0x1750 net/ipv6/ip6_output.c:141 __ip6_finish_output net/ipv6/ip6_output.c:-1 [inline] ip6_finish_output+0x421/0x840 net/ipv6/ip6_output.c:226 NF_HOOK include/linux/netfilter.h:314 [inline] ndisc_send_skb+0xb58/0x1560 net/ipv6/ndisc.c:513 addrconf_rs_timer+0x380/0x680 net/ipv6/addrconf.c:4037 call_timer_fn+0x189/0x650 kernel/time/timer.c:1789 expire_timers kernel/time/timer.c:1840 [inline] __run_timers kernel/time/timer.c:2414 [inline] __run_timer_base+0x66e/0x8e0 kernel/time/timer.c:2426 run_timer_base kernel/time/timer.c:2435 [inline] run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2445 handle_softirqs+0x2d6/0x9b0 kernel/softirq.c:579 __do_softirq kernel/softirq.c:613 [inline] invoke_softirq kernel/softirq.c:453 [inline] __irq_exit_rcu+0xfb/0x220 kernel/softirq.c:680 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_acquire+0x167/0x2f0 arch/x86/include/asm/irqflags.h:-1 Code: c7 44 24 10 00 00 00 00 9c 8f 44 24 10 f7 44 24 10 00 02 00 00 0f 85 fd 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 65 48 8b 45 00 <48> 3b 44 24 38 0f 85 72 01 00 00 48 83 c4 40 5b 41 5c 41 5d 41 5e RSP: 0018:ffffc9000484f3f8 EFLAGS: 00000206 RAX: 60424aacb0edd400 RBX: ffffffff8ed3dfe0 RCX: 60424aacb0edd400 RDX: 0000000000000000 RSI: ffffffff8e4fce8a RDI: ffffffff8ca1b120 RBP: ffffffff9368a020 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000002 R14: 0000000000000246 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] class_rcu_constructor include/linux/rcupdate.h:1155 [inline] kernfs_root+0x39/0x230 fs/kernfs/kernfs-internal.h:73 kernfs_root_is_locked fs/kernfs/kernfs-internal.h:107 [inline] kernfs_rcu_name fs/kernfs/kernfs-internal.h:112 [inline] kernfs_sd_compare fs/kernfs/dir.c:349 [inline] kernfs_link_sibling+0xf1/0x3b0 fs/kernfs/dir.c:380 kernfs_add_one+0x1ef/0x530 fs/kernfs/dir.c:810 __kernfs_create_file+0x22e/0x2e0 fs/kernfs/file.c:1067 sysfs_add_file_mode_ns+0x24a/0x310 fs/sysfs/file.c:319 create_files fs/sysfs/group.c:76 [inline] internal_create_group+0x7ea/0x1320 fs/sysfs/group.c:183 internal_create_groups fs/sysfs/group.c:223 [inline] sysfs_create_groups+0x56/0x120 fs/sysfs/group.c:249 setup_port drivers/infiniband/core/sysfs.c:1247 [inline] ib_setup_port_attrs+0xfc7/0x2490 drivers/infiniband/core/sysfs.c:1433 add_one_compat_dev+0x59e/0x7a0 drivers/infiniband/core/device.c:968 rdma_dev_init_net+0x1f5/0x280 drivers/infiniband/core/device.c:1184 ops_init+0x349/0x5b0 net/core/net_namespace.c:138 setup_net+0x289/0x9f0 net/core/net_namespace.c:364 copy_net_ns+0x33f/0x570 net/core/net_namespace.c:518 create_new_namespaces+0x425/0x7b0 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0x124/0x180 kernel/nsproxy.c:228 ksys_unshare+0x5e2/0xad0 kernel/fork.c:3375 __do_sys_unshare kernel/fork.c:3446 [inline] __se_sys_unshare kernel/fork.c:3444 [inline] __x64_sys_unshare+0x38/0x40 kernel/fork.c:3444 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: 0033:0x7f412398d169 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:00007f412473d038 EFLAGS: 00000246 ORIG_RAX: 0000000000000110 RAX: ffffffffffffffda RBX: 00007f4123ba5fa0 RCX: 00007f412398d169 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000062040200 RBP: 00007f4123a0e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f4123ba5fa0 R15: 00007ffe4ef6c8e8 ---------------- Code disassembly (best guess): 0: c7 44 24 10 00 00 00 movl $0x0,0x10(%rsp) 7: 00 8: 9c pushf 9: 8f 44 24 10 pop 0x10(%rsp) d: f7 44 24 10 00 02 00 testl $0x200,0x10(%rsp) 14: 00 15: 0f 85 fd 00 00 00 jne 0x118 1b: 41 f7 c6 00 02 00 00 test $0x200,%r14d 22: 74 01 je 0x25 24: fb sti 25: 65 48 8b 45 00 mov %gs:0x0(%rbp),%rax * 2a: 48 3b 44 24 38 cmp 0x38(%rsp),%rax <-- trapping instruction 2f: 0f 85 72 01 00 00 jne 0x1a7 35: 48 83 c4 40 add $0x40,%rsp 39: 5b pop %rbx 3a: 41 5c pop %r12 3c: 41 5d pop %r13 3e: 41 5e pop %r14