============================================ WARNING: possible recursive locking detected syzkaller #0 Not tainted -------------------------------------------- syz.4.6726/574 is trying to acquire lock: ffff88805b428fb0 (&hsr->seqnr_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:348 [inline] ffff88805b428fb0 (&hsr->seqnr_lock){+.-.}-{3:3}, at: hsr_dev_xmit+0x237/0x360 net/hsr/hsr_device.c:235 but task is already holding lock: ffff88801b7b0fb0 (&hsr->seqnr_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:348 [inline] ffff88801b7b0fb0 (&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 12 locks held by syz.4.6726/574: #0: ffffffff8fdceac0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8fdceac0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8fdceac0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x883/0x1bb0 net/core/rtnetlink.c:4107 #1: ffff888065b90780 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: class_wiphy_constructor include/net/cfg80211.h:6645 [inline] #1: ffff888065b90780 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: ieee80211_stop+0x126/0x220 net/mac80211/iface.c:846 #2: ffff888058c6de50 (&sb->s_type->i_mutex_key#4/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1074 [inline] #2: ffff888058c6de50 (&sb->s_type->i_mutex_key#4/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2914 [inline] #2: ffff888058c6de50 (&sb->s_type->i_mutex_key#4/1){+.+.}-{4:4}, at: start_dirop+0x4f/0x90 fs/namei.c:2938 #3: ffff888078658f20 (&sb->s_type->i_lock_key#9){+.+.}-{3:3}, at: spin_lock include/linux/spinlock.h:342 [inline] #3: ffff888078658f20 (&sb->s_type->i_lock_key#9){+.+.}-{3:3}, at: d_make_persistent+0x77/0x180 fs/dcache.c:2801 #4: ffffc90000007cc0 ((&hsr->announce_timer)){+.-.}-{0:0}, at: call_timer_fn+0xd4/0x5e0 kernel/time/timer.c:1745 #5: ffffffff8e95d020 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #5: ffffffff8e95d020 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #5: ffffffff8e95d020 (rcu_read_lock){....}-{1:3}, at: hsr_announce+0x89/0x370 net/hsr/hsr_device.c:419 #6: ffff88801b7b0fb0 (&hsr->seqnr_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:348 [inline] #6: ffff88801b7b0fb0 (&hsr->seqnr_lock){+.-.}-{3:3}, at: send_hsr_supervision_frame+0x380/0xcb0 net/hsr/hsr_device.c:330 #7: ffffffff8e95d020 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #7: ffffffff8e95d020 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #7: ffffffff8e95d020 (rcu_read_lock){....}-{1:3}, at: hsr_forward_skb+0xbb/0x2a80 net/hsr/hsr_forward.c:738 #8: ffffffff8e95d080 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #8: ffffffff8e95d080 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:891 [inline] #8: ffffffff8e95d080 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x2b6/0x3950 net/core/dev.c:4791 #9: ffffffff8e95d020 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #9: ffffffff8e95d020 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #9: ffffffff8e95d020 (rcu_read_lock){....}-{1:3}, at: br_dev_xmit+0x193/0x1990 net/bridge/br_device.c:52 #10: ffffffff8e95d080 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #10: ffffffff8e95d080 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:891 [inline] #10: ffffffff8e95d080 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x2b6/0x3950 net/core/dev.c:4791 #11: ffffffff8e95d020 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #11: ffffffff8e95d020 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #11: ffffffff8e95d020 (rcu_read_lock){....}-{1:3}, at: hsr_dev_xmit+0x2d/0x360 net/hsr/hsr_device.c:229 stack backtrace: CPU: 0 UID: 0 PID: 574 Comm: syz.4.6726 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 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+0x106/0x350 kernel/locking/lockdep.c:5868 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:150 [inline] _raw_spin_lock_bh+0x36/0x50 kernel/locking/spinlock.c:182 spin_lock_bh include/linux/spinlock.h:348 [inline] hsr_dev_xmit+0x237/0x360 net/hsr/hsr_device.c:235 __netdev_start_xmit include/linux/netdevice.h:5343 [inline] netdev_start_xmit include/linux/netdevice.h:5352 [inline] xmit_one net/core/dev.c:3888 [inline] dev_hard_start_xmit+0x2cd/0x830 net/core/dev.c:3904 __dev_queue_xmit+0x14d9/0x3950 net/core/dev.c:4870 dev_queue_xmit include/linux/netdevice.h:3401 [inline] br_dev_queue_push_xmit+0x370/0x4b0 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+0x12bd/0x1990 net/bridge/br_device.c:108 __netdev_start_xmit include/linux/netdevice.h:5343 [inline] netdev_start_xmit include/linux/netdevice.h:5352 [inline] xmit_one net/core/dev.c:3888 [inline] dev_hard_start_xmit+0x2cd/0x830 net/core/dev.c:3904 __dev_queue_xmit+0x14d9/0x3950 net/core/dev.c:4870 dev_queue_xmit include/linux/netdevice.h:3401 [inline] hsr_xmit net/hsr/hsr_forward.c:440 [inline] hsr_forward_do net/hsr/hsr_forward.c:581 [inline] hsr_forward_skb+0x167e/0x2a80 net/hsr/hsr_forward.c:743 send_hsr_supervision_frame+0x731/0xcb0 net/hsr/hsr_device.c:364 hsr_announce+0x1db/0x370 net/hsr/hsr_device.c:421 call_timer_fn+0x192/0x5e0 kernel/time/timer.c:1748 expire_timers kernel/time/timer.c:1799 [inline] __run_timers kernel/time/timer.c:2374 [inline] __run_timer_base+0x652/0x8b0 kernel/time/timer.c:2386 run_timer_base kernel/time/timer.c:2395 [inline] run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2405 handle_softirqs+0x22a/0x840 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0xca/0x220 kernel/softirq.c:735 irq_exit_rcu+0x9/0x30 kernel/softirq.c:752 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1061 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_acquire+0x221/0x350 kernel/locking/lockdep.c:5872 Code: ff ff ff e8 b1 9d 11 0a f7 44 24 08 00 02 00 00 0f 84 3a ff ff ff 65 48 8b 05 8b 38 9c 11 48 3b 44 24 58 75 33 fb 48 83 c4 60 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 48 8d 3d 98 f2 93 RSP: 0018:ffffc9000edae578 EFLAGS: 00000286 RAX: 76c07306bf4b9700 RBX: 0000000000000000 RCX: 0000000080000001 RDX: 000000007f127300 RSI: ffffffff8e22a119 RDI: ffffffff8c27f000 RBP: ffffffff824ac917 R08: ffffffff824ac917 R09: ffff888078658f20 R10: dffffc0000000000 R11: fffffbfff20642b7 R12: 0000000000000000 R13: ffff888078658f20 R14: 0000000000000001 R15: 0000000000000246 __raw_spin_lock include/linux/spinlock_api_smp.h:158 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:158 spin_lock include/linux/spinlock.h:342 [inline] d_make_persistent+0x77/0x180 fs/dcache.c:2801 __debugfs_create_file+0x1e4/0x400 fs/debugfs/inode.c:450 debugfs_create_file_short+0x3f/0x60 fs/debugfs/inode.c:471 add_common_files net/mac80211/debugfs_netdev.c:827 [inline] add_files net/mac80211/debugfs_netdev.c:946 [inline] ieee80211_debugfs_add_netdev net/mac80211/debugfs_netdev.c:1010 [inline] ieee80211_debugfs_recreate_netdev+0x416/0x1460 net/mac80211/debugfs_netdev.c:1034 drv_remove_interface+0x1ed/0x570 net/mac80211/driver-ops.c:125 ieee80211_do_stop+0x1706/0x2250 net/mac80211/iface.c:750 ieee80211_stop+0x1b1/0x220 net/mac80211/iface.c:856 __dev_close_many+0x36d/0x6e0 net/core/dev.c:1776 __dev_close net/core/dev.c:1788 [inline] __dev_change_flags+0x2cb/0x690 net/core/dev.c:9808 netif_change_flags+0x88/0x1a0 net/core/dev.c:9873 do_setlink+0xf82/0x4590 net/core/rtnetlink.c:3180 rtnl_group_changelink net/core/rtnetlink.c:3812 [inline] __rtnl_newlink net/core/rtnetlink.c:3980 [inline] rtnl_newlink+0x14ca/0x1bb0 net/core/rtnetlink.c:4108 rtnetlink_rcv_msg+0x7d5/0xbe0 net/core/rtnetlink.c:6994 netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2550 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x75c/0x8e0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:787 [inline] __sock_sendmsg net/socket.c:802 [inline] ____sys_sendmsg+0x972/0x9f0 net/socket.c:2698 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2752 __sys_sendmsg net/socket.c:2784 [inline] __do_sys_sendmsg net/socket.c:2789 [inline] __se_sys_sendmsg net/socket.c:2787 [inline] __x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2787 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe77a79c819 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:00007fe7789f6028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fe77aa15fa0 RCX: 00007fe77a79c819 RDX: 0000000000008024 RSI: 0000200000000140 RDI: 0000000000000007 RBP: 00007fe77a832c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fe77aa16038 R14: 00007fe77aa15fa0 R15: 00007ffcd41b42f8 ---------------- Code disassembly (best guess), 2 bytes skipped: 0: ff ljmp (bad) 1: e8 b1 9d 11 0a call 0xa119db7 6: f7 44 24 08 00 02 00 testl $0x200,0x8(%rsp) d: 00 e: 0f 84 3a ff ff ff je 0xffffff4e 14: 65 48 8b 05 8b 38 9c mov %gs:0x119c388b(%rip),%rax # 0x119c38a7 1b: 11 1c: 48 3b 44 24 58 cmp 0x58(%rsp),%rax 21: 75 33 jne 0x56 23: fb sti 24: 48 83 c4 60 add $0x60,%rsp * 28: 5b pop %rbx <-- trapping instruction 29: 41 5c pop %r12 2b: 41 5d pop %r13 2d: 41 5e pop %r14 2f: 41 5f pop %r15 31: 5d pop %rbp 32: c3 ret 33: cc int3 34: cc int3 35: cc int3 36: cc int3 37: cc int3 38: 48 rex.W 39: 8d .byte 0x8d 3a: 3d .byte 0x3d 3b: 98 cwtl 3c: f2 93 repnz xchg %eax,%ebx