============================================ WARNING: possible recursive locking detected 6.8.0-syzkaller-08073-g480e035fc4c7-dirty #0 Not tainted -------------------------------------------- kworker/0:1/8 is trying to acquire lock: ffff88806df74da0 (&hsr->seqnr_lock/1){+.-.}-{2:2}, at: hsr_dev_xmit+0x157/0x200 net/hsr/hsr_device.c:230 but task is already holding lock: ffff888069ca6da0 (&hsr->seqnr_lock/1){+.-.}-{2:2}, at: hsr_dev_xmit+0x157/0x200 net/hsr/hsr_device.c:230 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&hsr->seqnr_lock/1); lock(&hsr->seqnr_lock/1); *** DEADLOCK *** May be due to missing lock nesting notation 11 locks held by kworker/0:1/8: #0: ffff888029984d48 ((wq_completion)mld){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3229 [inline] #0: ffff888029984d48 ((wq_completion)mld){+.+.}-{0:0}, at: process_scheduled_works+0x8e0/0x1770 kernel/workqueue.c:3335 #1: ffffc900000d7d00 ((work_completion)(&(&idev->mc_ifc_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3230 [inline] #1: ffffc900000d7d00 ((work_completion)(&(&idev->mc_ifc_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x91b/0x1770 kernel/workqueue.c:3335 #2: ffff88806a227538 (&idev->mc_lock){+.+.}-{3:3}, at: mld_ifc_work+0x2d/0xd90 net/ipv6/mcast.c:2649 #3: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline] #3: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline] #3: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: mld_sendpack+0x1de/0xda0 net/ipv6/mcast.c:1790 #4: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline] #4: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline] #4: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: ip6_finish_output2+0x712/0x1670 net/ipv6/ip6_output.c:122 #5: ffffffff8e132080 (rcu_read_lock_bh){....}-{1:2}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #5: ffffffff8e132080 (rcu_read_lock_bh){....}-{1:2}, at: rcu_read_lock_bh include/linux/rcupdate.h:802 [inline] #5: ffffffff8e132080 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x2c4/0x3b10 net/core/dev.c:4260 #6: ffff888069ca6da0 (&hsr->seqnr_lock/1){+.-.}-{2:2}, at: hsr_dev_xmit+0x157/0x200 net/hsr/hsr_device.c:230 #7: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline] #7: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline] #7: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: hsr_forward_skb+0xae/0x2400 net/hsr/hsr_forward.c:614 #8: ffffffff8e132080 (rcu_read_lock_bh){....}-{1:2}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #8: ffffffff8e132080 (rcu_read_lock_bh){....}-{1:2}, at: rcu_read_lock_bh include/linux/rcupdate.h:802 [inline] #8: ffffffff8e132080 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x2c4/0x3b10 net/core/dev.c:4260 #9: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline] #9: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline] #9: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: br_dev_xmit+0x1b9/0x1a10 net/bridge/br_device.c:44 #10: ffffffff8e132080 (rcu_read_lock_bh){....}-{1:2}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #10: ffffffff8e132080 (rcu_read_lock_bh){....}-{1:2}, at: rcu_read_lock_bh include/linux/rcupdate.h:802 [inline] #10: ffffffff8e132080 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x2c4/0x3b10 net/core/dev.c:4260 stack backtrace: CPU: 0 PID: 8 Comm: kworker/0:1 Not tainted 6.8.0-syzkaller-08073-g480e035fc4c7-dirty #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Workqueue: mld mld_ifc_work Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 check_deadlock kernel/locking/lockdep.c:3062 [inline] validate_chain+0x15c1/0x58e0 kernel/locking/lockdep.c:3856 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137 lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754 _raw_spin_lock_nested+0x31/0x40 kernel/locking/spinlock.c:378 hsr_dev_xmit+0x157/0x200 net/hsr/hsr_device.c:230 __netdev_start_xmit include/linux/netdevice.h:4903 [inline] netdev_start_xmit include/linux/netdevice.h:4917 [inline] xmit_one net/core/dev.c:3531 [inline] dev_hard_start_xmit+0x26a/0x790 net/core/dev.c:3547 __dev_queue_xmit+0x19f4/0x3b10 net/core/dev.c:4335 dev_queue_xmit include/linux/netdevice.h:3091 [inline] br_dev_queue_push_xmit+0x701/0x8d0 net/bridge/br_forward.c:53 NF_HOOK+0x3a7/0x460 include/linux/netfilter.h:314 br_forward_finish+0xe5/0x140 net/bridge/br_forward.c:66 NF_HOOK+0x3a7/0x460 include/linux/netfilter.h:314 __br_forward+0x489/0x660 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+0x2e4/0x660 net/bridge/br_forward.c:236 br_dev_xmit+0x118c/0x1a10 __netdev_start_xmit include/linux/netdevice.h:4903 [inline] netdev_start_xmit include/linux/netdevice.h:4917 [inline] xmit_one net/core/dev.c:3531 [inline] dev_hard_start_xmit+0x26a/0x790 net/core/dev.c:3547 __dev_queue_xmit+0x19f4/0x3b10 net/core/dev.c:4335 dev_queue_xmit include/linux/netdevice.h:3091 [inline] hsr_xmit net/hsr/hsr_forward.c:380 [inline] hsr_forward_do net/hsr/hsr_forward.c:471 [inline] hsr_forward_skb+0x183f/0x2400 net/hsr/hsr_forward.c:619 hsr_dev_xmit+0x162/0x200 net/hsr/hsr_device.c:231 __netdev_start_xmit include/linux/netdevice.h:4903 [inline] netdev_start_xmit include/linux/netdevice.h:4917 [inline] xmit_one net/core/dev.c:3531 [inline] dev_hard_start_xmit+0x26a/0x790 net/core/dev.c:3547 __dev_queue_xmit+0x19f4/0x3b10 net/core/dev.c:4335 neigh_output include/net/neighbour.h:542 [inline] ip6_finish_output2+0xff8/0x1670 net/ipv6/ip6_output.c:137 ip6_finish_output+0x41e/0x810 net/ipv6/ip6_output.c:222 NF_HOOK+0x9e/0x430 include/linux/netfilter.h:314 mld_sendpack+0x838/0xda0 net/ipv6/mcast.c:1818 mld_send_cr net/ipv6/mcast.c:2119 [inline] mld_ifc_work+0x7d6/0xd90 net/ipv6/mcast.c:2650 process_one_work kernel/workqueue.c:3254 [inline] process_scheduled_works+0xa00/0x1770 kernel/workqueue.c:3335 worker_thread+0x86d/0xd70 kernel/workqueue.c:3416 kthread+0x2f0/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243