============================================ WARNING: possible recursive locking detected 6.15.0-rc1-syzkaller-00220-g6a325aed130b #0 Not tainted -------------------------------------------- syz-executor/9198 is trying to acquire lock: ffff88805f9a2f30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] ffff88805f9a2f30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: hsr_dev_xmit+0x18a/0x210 net/hsr/hsr_device.c:234 but task is already holding lock: ffff888027b12f30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] ffff888027b12f30 (&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 11 locks held by syz-executor/9198: #0: ffffffff8f890b20 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8f890b20 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8f890b20 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x22/0x250 net/core/rtnetlink.c:570 #1: ffffffff900fd448 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff900fd448 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff900fd448 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xd68/0x1fe0 net/core/rtnetlink.c:4067 #2: ffffc90000007bc0 ((&ndev->rs_timer)){+.-.}-{0:0}, at: call_timer_fn+0xc2/0x650 kernel/time/timer.c:1786 #3: ffffffff8ed3dfe0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #3: ffffffff8ed3dfe0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #3: ffffffff8ed3dfe0 (rcu_read_lock){....}-{1:3}, at: ndisc_send_skb+0x1ef/0x1560 net/ipv6/ndisc.c:484 #4: ffffffff8ed3dfe0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #4: ffffffff8ed3dfe0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #4: ffffffff8ed3dfe0 (rcu_read_lock){....}-{1:3}, at: ip6_finish_output2+0x701/0x1750 net/ipv6/ip6_output.c:126 #5: ffffffff8ed3e040 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #5: ffffffff8ed3e040 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:892 [inline] #5: ffffffff8ed3e040 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x2f9/0x3f60 net/core/dev.c:4604 #6: ffff888027b12f30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] #6: ffff888027b12f30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: hsr_dev_xmit+0x18a/0x210 net/hsr/hsr_device.c:234 #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: hsr_forward_skb+0xb8/0x2d20 net/hsr/hsr_forward.c:728 #8: ffffffff8ed3e040 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #8: ffffffff8ed3e040 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:892 [inline] #8: ffffffff8ed3e040 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x2f9/0x3f60 net/core/dev.c:4604 #9: ffffffff8ed3dfe0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #9: ffffffff8ed3dfe0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #9: ffffffff8ed3dfe0 (rcu_read_lock){....}-{1:3}, at: br_dev_xmit+0x220/0x1c00 net/bridge/br_device.c:52 #10: ffffffff8ed3e040 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #10: ffffffff8ed3e040 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:892 [inline] #10: ffffffff8ed3e040 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x2f9/0x3f60 net/core/dev.c:4604 stack backtrace: CPU: 0 UID: 0 PID: 9198 Comm: syz-executor Not tainted 6.15.0-rc1-syzkaller-00220-g6a325aed130b #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:5209 [inline] netdev_start_xmit include/linux/netdevice.h:5218 [inline] xmit_one net/core/dev.c:3826 [inline] dev_hard_start_xmit+0x2d9/0x830 net/core/dev.c:3842 __dev_queue_xmit+0x1b80/0x3f60 net/core/dev.c:4679 dev_queue_xmit include/linux/netdevice.h:3355 [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 br_dev_xmit+0x12ac/0x1c00 net/bridge/br_device.c:-1 __netdev_start_xmit include/linux/netdevice.h:5209 [inline] netdev_start_xmit include/linux/netdevice.h:5218 [inline] xmit_one net/core/dev.c:3826 [inline] dev_hard_start_xmit+0x2d9/0x830 net/core/dev.c:3842 __dev_queue_xmit+0x1b80/0x3f60 net/core/dev.c:4679 dev_queue_xmit include/linux/netdevice.h:3355 [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:5209 [inline] netdev_start_xmit include/linux/netdevice.h:5218 [inline] xmit_one net/core/dev.c:3826 [inline] dev_hard_start_xmit+0x2d9/0x830 net/core/dev.c:3842 __dev_queue_xmit+0x1b80/0x3f60 net/core/dev.c:4679 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:4038 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:kasan_byte_accessible+0x16/0x20 mm/kasan/generic.c:201 Code: 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 66 0f 1f 00 48 c1 ef 03 48 b8 00 00 00 00 00 fc ff df 0f b6 04 07 <3c> 08 0f 92 c0 c3 cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc9000b61e9d0 EFLAGS: 00000a06 RAX: 0000000000000000 RBX: ffff88801da82528 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff8c2ebe2e RDI: 1ffff11003b504a5 RBP: ffffffff93670020 R08: 0000000000000001 R09: 0000000000000000 R10: dffffc0000000000 R11: fffffbfff20bef8f R12: 0000000000000001 R13: 0000000000000000 R14: ffffffff8c2ebe2e R15: ffff88801da82528 __kasan_check_byte+0x14/0x40 mm/kasan/common.c:556 kasan_check_byte include/linux/kasan.h:399 [inline] lock_acquire+0x89/0x2f0 kernel/locking/lockdep.c:5840 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] class_to_subsys+0x41/0x120 drivers/base/class.c:50 device_add+0x96f/0xbf0 drivers/base/core.c:3680 netdev_register_kobject+0x157/0x2f0 net/core/net-sysfs.c:2336 register_netdevice+0x12b0/0x1b80 net/core/dev.c:11062 veth_newlink+0x4c3/0xb80 drivers/net/veth.c:1818 rtnl_newlink_create+0x39b/0xcb0 net/core/rtnetlink.c:3836 __rtnl_newlink net/core/rtnetlink.c:3953 [inline] rtnl_newlink+0x18b0/0x1fe0 net/core/rtnetlink.c:4068 rtnetlink_rcv_msg+0x80f/0xd70 net/core/rtnetlink.c:6958 netlink_rcv_skb+0x208/0x480 net/netlink/af_netlink.c:2534 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline] netlink_unicast+0x7f8/0x9a0 net/netlink/af_netlink.c:1339 netlink_sendmsg+0x8c3/0xcd0 net/netlink/af_netlink.c:1883 sock_sendmsg_nosec net/socket.c:712 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:727 __sys_sendto+0x365/0x4c0 net/socket.c:2180 __do_sys_sendto net/socket.c:2187 [inline] __se_sys_sendto net/socket.c:2183 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2183 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: 0033:0x7f684118effc Code: 2a 5f 02 00 44 8b 4c 24 2c 4c 8b 44 24 20 89 c5 44 8b 54 24 28 48 8b 54 24 18 b8 2c 00 00 00 48 8b 74 24 10 8b 7c 24 08 0f 05 <48> 3d 00 f0 ff ff 77 34 89 ef 48 89 44 24 08 e8 70 5f 02 00 48 8b RSP: 002b:00007ffe3457dbe0 EFLAGS: 00000293 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f6841ed4620 RCX: 00007f684118effc RDX: 0000000000000064 RSI: 00007f6841ed4670 RDI: 0000000000000003 RBP: 0000000000000000 R08: 00007ffe3457dc34 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003 R13: 0000000000000000 R14: 00007f6841ed4670 R15: 0000000000000000 ---------------- Code disassembly (best guess): 0: 00 00 add %al,(%rax) 2: 00 00 add %al,(%rax) 4: 90 nop 5: 90 nop 6: 90 nop 7: 90 nop 8: 90 nop 9: 90 nop a: 90 nop b: 90 nop c: 90 nop d: 90 nop e: 90 nop f: 90 nop 10: 90 nop 11: 90 nop 12: 90 nop 13: 90 nop 14: 66 0f 1f 00 nopw (%rax) 18: 48 c1 ef 03 shr $0x3,%rdi 1c: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 23: fc ff df 26: 0f b6 04 07 movzbl (%rdi,%rax,1),%eax * 2a: 3c 08 cmp $0x8,%al <-- trapping instruction 2c: 0f 92 c0 setb %al 2f: c3 ret 30: cc int3 31: cc int3 32: cc int3 33: cc int3 34: 90 nop 35: 90 nop 36: 90 nop 37: 90 nop 38: 90 nop 39: 90 nop 3a: 90 nop 3b: 90 nop 3c: 90 nop 3d: 90 nop 3e: 90 nop 3f: 90 nop