syzbot


possible deadlock in __ipv6_dev_mc_inc

Status: upstream: reported on 2026/03/16 10:33
Subsystems: net
Labels: prio:high
[Documentation on labels]
Reported-by: syzbot+afbcf622635e98bf40d2@syzkaller.appspotmail.com
First crash: 89d, last: 55m
✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision Error
78f28151-21c3-4070-8939-647ca9aad300 assessment-security DenialOfService: ❌ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ✅ UserNamespace: ✅ VMGuestTrigger: ❌ VMHostTrigger: ❌ possible deadlock in __ipv6_dev_mc_inc 2026/05/18 20:55 2026/05/18 21:04 2026/05/18 21:52 9f74d39908454b73546eaf1b8211b48b66e5c0fe
Discussions (3)
Title Replies (including bot) Last reply
[syzbot] Monthly net report (May 2026) 0 (1) 2026/05/23 12:32
[PATCH net v1] net/ipv6: mcast: fix circular locking dependency in __ipv6_dev_mc_inc() 9 (9) 2026/03/23 06:54
[syzbot] [net?] possible deadlock in __ipv6_dev_mc_inc 0 (1) 2026/03/16 10:33

Sample crash report:
(unnamed net_device) (uninitialized): Assigned a random MAC address: 86:93:70:7d:4d:25
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Tainted: G             L     
------------------------------------------------------
kworker/0:1/10 is trying to acquire lock:
ffffffff8ea85540 (fs_reclaim){+.+.}-{0:0}, at: might_alloc include/linux/sched/mm.h:317 [inline]
ffffffff8ea85540 (fs_reclaim){+.+.}-{0:0}, at: slab_pre_alloc_hook mm/slub.c:4521 [inline]
ffffffff8ea85540 (fs_reclaim){+.+.}-{0:0}, at: slab_alloc_node mm/slub.c:4876 [inline]
ffffffff8ea85540 (fs_reclaim){+.+.}-{0:0}, at: __kmalloc_cache_noprof+0x40/0x660 mm/slub.c:5415

but task is already holding lock:
ffff888079c97530 (&idev->mc_lock){+.+.}-{4:4}, at: __ipv6_dev_mc_inc+0x4e/0xa50 net/ipv6/mcast.c:943

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #7 (&idev->mc_lock){+.+.}-{4:4}:
       __mutex_lock_common kernel/locking/mutex.c:646 [inline]
       __mutex_lock+0x1a3/0x1550 kernel/locking/mutex.c:820
       ip6_mc_source+0x1cc/0x17e0 net/ipv6/mcast.c:376
       do_ipv6_mcast_group_source+0x435/0x4c0 net/ipv6/ipv6_sockglue.c:184
       do_ipv6_setsockopt+0x16e9/0x3150 net/ipv6/ipv6_sockglue.c:911
       ipv6_setsockopt+0x59/0x170 net/ipv6/ipv6_sockglue.c:965
       do_sock_setsockopt+0x17c/0x1b0 net/socket.c:2381
       __sys_setsockopt net/socket.c:2406 [inline]
       __do_sys_setsockopt net/socket.c:2412 [inline]
       __se_sys_setsockopt net/socket.c:2409 [inline]
       __x64_sys_setsockopt+0x13d/0x1b0 net/socket.c:2409
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #6 (sk_lock-AF_INET6){+.+.}-{0:0}:
       lock_sock_nested+0x41/0x100 net/core/sock.c:3787
       lock_sock include/net/sock.h:1713 [inline]
       inet_shutdown+0x6a/0x390 net/ipv4/af_inet.c:915
       nbd_mark_nsock_dead+0x2e9/0x560 drivers/block/nbd.c:318
       sock_shutdown+0x15e/0x260 drivers/block/nbd.c:411
       nbd_clear_sock+0x24/0x170 drivers/block/nbd.c:1427
       nbd_config_put+0x2dd/0x580 drivers/block/nbd.c:1451
       nbd_genl_connect+0x19d5/0x1cf0 drivers/block/nbd.c:2248
       genl_family_rcv_msg_doit+0x22a/0x330 net/netlink/genetlink.c:1114
       genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline]
       genl_rcv_msg+0x61c/0x7a0 net/netlink/genetlink.c:1209
       netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2555
       genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218
       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:1899
       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+0x174/0x580 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #5 (&nsock->tx_lock){+.+.}-{4:4}:
       __mutex_lock_common kernel/locking/mutex.c:646 [inline]
       __mutex_lock+0x1a3/0x1550 kernel/locking/mutex.c:820
       nbd_handle_cmd drivers/block/nbd.c:1143 [inline]
       nbd_queue_rq+0x37b/0x1100 drivers/block/nbd.c:1207
       blk_mq_dispatch_rq_list+0xa70/0x1910 block/blk-mq.c:2148
       __blk_mq_do_dispatch_sched block/blk-mq-sched.c:168 [inline]
       blk_mq_do_dispatch_sched block/blk-mq-sched.c:182 [inline]
       __blk_mq_sched_dispatch_requests+0xdcc/0x1600 block/blk-mq-sched.c:307
       blk_mq_sched_dispatch_requests+0xd7/0x190 block/blk-mq-sched.c:329
       blk_mq_run_hw_queue+0x348/0x4f0 block/blk-mq.c:2386
       blk_mq_dispatch_list+0xd16/0xe10 include/linux/spinlock.h:-1
       blk_mq_flush_plug_list+0x48d/0x570 block/blk-mq.c:2997
       __blk_flush_plug+0x3ed/0x4d0 block/blk-core.c:1230
       blk_finish_plug block/blk-core.c:1257 [inline]
       __submit_bio+0x28d/0x580 block/blk-core.c:649
       __submit_bio_noacct_mq block/blk-core.c:722 [inline]
       submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:753
       submit_bh fs/buffer.c:2742 [inline]
       block_read_full_folio+0x599/0x830 fs/buffer.c:2344
       filemap_read_folio+0x137/0x3b0 mm/filemap.c:2502
       do_read_cache_folio+0x358/0x590 mm/filemap.c:4107
       read_mapping_folio include/linux/pagemap.h:1017 [inline]
       read_part_sector+0xb6/0x2b0 block/partitions/core.c:724
       adfspart_check_ICS+0xb1/0x960 block/partitions/acorn.c:356
       check_partition block/partitions/core.c:143 [inline]
       blk_add_partitions block/partitions/core.c:591 [inline]
       bdev_disk_changed+0x817/0x1770 block/partitions/core.c:695
       blkdev_get_whole+0x380/0x510 block/bdev.c:756
       bdev_open+0x31e/0xd30 block/bdev.c:965
       blkdev_open+0x470/0x610 block/fops.c:697
       do_dentry_open+0x822/0x13a0 fs/open.c:947
       vfs_open+0x3b/0x340 fs/open.c:1079
       do_open fs/namei.c:4699 [inline]
       path_openat+0x2e08/0x3860 fs/namei.c:4858
       do_file_open+0x23e/0x4a0 fs/namei.c:4887
       do_sys_openat2+0x113/0x200 fs/open.c:1364
       do_sys_open fs/open.c:1370 [inline]
       __do_sys_openat fs/open.c:1386 [inline]
       __se_sys_openat fs/open.c:1381 [inline]
       __x64_sys_openat+0x138/0x170 fs/open.c:1381
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #4 (&cmd->lock){+.+.}-{4:4}:
       __mutex_lock_common kernel/locking/mutex.c:646 [inline]
       __mutex_lock+0x1a3/0x1550 kernel/locking/mutex.c:820
       nbd_queue_rq+0xc6/0x1100 drivers/block/nbd.c:1199
       blk_mq_dispatch_rq_list+0xa70/0x1910 block/blk-mq.c:2148
       __blk_mq_do_dispatch_sched block/blk-mq-sched.c:168 [inline]
       blk_mq_do_dispatch_sched block/blk-mq-sched.c:182 [inline]
       __blk_mq_sched_dispatch_requests+0xdcc/0x1600 block/blk-mq-sched.c:307
       blk_mq_sched_dispatch_requests+0xd7/0x190 block/blk-mq-sched.c:329
       blk_mq_run_hw_queue+0x348/0x4f0 block/blk-mq.c:2386
       blk_mq_dispatch_list+0xd16/0xe10 include/linux/spinlock.h:-1
       blk_mq_flush_plug_list+0x48d/0x570 block/blk-mq.c:2997
       __blk_flush_plug+0x3ed/0x4d0 block/blk-core.c:1230
       blk_finish_plug block/blk-core.c:1257 [inline]
       __submit_bio+0x28d/0x580 block/blk-core.c:649
       __submit_bio_noacct_mq block/blk-core.c:722 [inline]
       submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:753
       submit_bh fs/buffer.c:2742 [inline]
       block_read_full_folio+0x599/0x830 fs/buffer.c:2344
       filemap_read_folio+0x137/0x3b0 mm/filemap.c:2502
       do_read_cache_folio+0x358/0x590 mm/filemap.c:4107
       read_mapping_folio include/linux/pagemap.h:1017 [inline]
       read_part_sector+0xb6/0x2b0 block/partitions/core.c:724
       adfspart_check_ICS+0xb1/0x960 block/partitions/acorn.c:356
       check_partition block/partitions/core.c:143 [inline]
       blk_add_partitions block/partitions/core.c:591 [inline]
       bdev_disk_changed+0x817/0x1770 block/partitions/core.c:695
       blkdev_get_whole+0x380/0x510 block/bdev.c:756
       bdev_open+0x31e/0xd30 block/bdev.c:965
       blkdev_open+0x470/0x610 block/fops.c:697
       do_dentry_open+0x822/0x13a0 fs/open.c:947
       vfs_open+0x3b/0x340 fs/open.c:1079
       do_open fs/namei.c:4699 [inline]
       path_openat+0x2e08/0x3860 fs/namei.c:4858
       do_file_open+0x23e/0x4a0 fs/namei.c:4887
       do_sys_openat2+0x113/0x200 fs/open.c:1364
       do_sys_open fs/open.c:1370 [inline]
       __do_sys_openat fs/open.c:1386 [inline]
       __se_sys_openat fs/open.c:1381 [inline]
       __x64_sys_openat+0x138/0x170 fs/open.c:1381
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #3 (set->srcu){.+.+}-{0:0}:
       srcu_lock_sync include/linux/srcu.h:199 [inline]
       __synchronize_srcu+0xca/0x300 kernel/rcu/srcutree.c:1481
       elevator_switch+0x1e8/0x7a0 block/elevator.c:576
       elevator_change+0x2cc/0x450 block/elevator.c:681
       elevator_set_default+0x36c/0x430 block/elevator.c:754
       blk_register_queue+0x3e9/0x4e0 block/blk-sysfs.c:987
       __add_disk+0x677/0xd50 block/genhd.c:528
       add_disk_fwnode+0xfb/0x480 block/genhd.c:597
       add_disk include/linux/blkdev.h:794 [inline]
       nbd_dev_add+0x72c/0xb50 drivers/block/nbd.c:1984
       nbd_init+0x168/0x1f0 drivers/block/nbd.c:2692
       do_one_initcall+0x250/0x870 init/main.c:1392
       do_initcall_level+0x104/0x190 init/main.c:1454
       do_initcalls+0x59/0xa0 init/main.c:1470
       kernel_init_freeable+0x2a6/0x3e0 init/main.c:1703
       kernel_init+0x1d/0x1d0 init/main.c:1593
       ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

-> #2 (&q->elevator_lock){+.+.}-{4:4}:
       __mutex_lock_common kernel/locking/mutex.c:646 [inline]
       __mutex_lock+0x1a3/0x1550 kernel/locking/mutex.c:820
       elevator_change+0x1b3/0x450 block/elevator.c:679
       elevator_set_none+0xb5/0x140 block/elevator.c:769
       blk_mq_elv_switch_none block/blk-mq.c:5134 [inline]
       __blk_mq_update_nr_hw_queues block/blk-mq.c:5179 [inline]
       blk_mq_update_nr_hw_queues+0x5e7/0x1a60 block/blk-mq.c:5244
       nbd_start_device+0x17f/0xb10 drivers/block/nbd.c:1489
       nbd_genl_connect+0x165b/0x1cf0 drivers/block/nbd.c:2239
       genl_family_rcv_msg_doit+0x22a/0x330 net/netlink/genetlink.c:1114
       genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline]
       genl_rcv_msg+0x61c/0x7a0 net/netlink/genetlink.c:1209
       netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2555
       genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218
       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:1899
       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+0x174/0x580 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #1 (&q->q_usage_counter(io)#50){++++}-{0:0}:
       blk_alloc_queue+0x546/0x680 block/blk-core.c:461
       blk_mq_alloc_queue block/blk-mq.c:4453 [inline]
       __blk_mq_alloc_disk+0x197/0x390 block/blk-mq.c:4500
       nbd_dev_add+0x499/0xb50 drivers/block/nbd.c:1954
       nbd_init+0x168/0x1f0 drivers/block/nbd.c:2692
       do_one_initcall+0x250/0x870 init/main.c:1392
       do_initcall_level+0x104/0x190 init/main.c:1454
       do_initcalls+0x59/0xa0 init/main.c:1470
       kernel_init_freeable+0x2a6/0x3e0 init/main.c:1703
       kernel_init+0x1d/0x1d0 init/main.c:1593
       ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

-> #0 (fs_reclaim){+.+.}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:3165 [inline]
       check_prevs_add kernel/locking/lockdep.c:3284 [inline]
       validate_chain kernel/locking/lockdep.c:3908 [inline]
       __lock_acquire+0x15a5/0x2cf0 kernel/locking/lockdep.c:5237
       lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868
       __fs_reclaim_acquire mm/page_alloc.c:4320 [inline]
       fs_reclaim_acquire+0x71/0x100 mm/page_alloc.c:4334
       might_alloc include/linux/sched/mm.h:317 [inline]
       slab_pre_alloc_hook mm/slub.c:4521 [inline]
       slab_alloc_node mm/slub.c:4876 [inline]
       __kmalloc_cache_noprof+0x40/0x660 mm/slub.c:5415
       kmalloc_noprof include/linux/slab.h:950 [inline]
       kzalloc_noprof include/linux/slab.h:1188 [inline]
       mca_alloc net/ipv6/mcast.c:871 [inline]
       __ipv6_dev_mc_inc+0x44f/0xa50 net/ipv6/mcast.c:961
       ipv6_add_dev+0xe34/0x13a0 net/ipv6/addrconf.c:472
       addrconf_notify+0x771/0x1050 net/ipv6/addrconf.c:3662
       notifier_call_chain+0x1ad/0x3d0 kernel/notifier.c:85
       call_netdevice_notifiers_extack net/core/dev.c:2287 [inline]
       call_netdevice_notifiers net/core/dev.c:2301 [inline]
       register_netdevice+0x18c9/0x1ec0 net/core/dev.c:11461
       register_netdev+0x40/0x60 net/core/dev.c:11539
       rtl8150_probe+0x399/0x470 drivers/net/usb/rtl8150.c:942
       usb_probe_interface+0x659/0xc70 drivers/usb/core/driver.c:396
       call_driver_probe drivers/base/dd.c:-1 [inline]
       really_probe+0x267/0xaf0 drivers/base/dd.c:709
       __driver_probe_device+0x1ef/0x380 drivers/base/dd.c:871
       driver_probe_device+0x4f/0x240 drivers/base/dd.c:901
       __device_attach_driver+0x279/0x430 drivers/base/dd.c:1029
       bus_for_each_drv+0x258/0x2f0 drivers/base/bus.c:500
       __device_attach+0x2c5/0x450 drivers/base/dd.c:1101
       device_initial_probe+0xa1/0xd0 drivers/base/dd.c:1156
       bus_probe_device+0x12a/0x220 drivers/base/bus.c:613
       device_add+0x7e9/0xbb0 drivers/base/core.c:3706
       usb_set_configuration+0x1a87/0x2110 drivers/usb/core/message.c:2268
       usb_generic_driver_probe+0x8d/0x150 drivers/usb/core/generic.c:250
       usb_probe_device+0x1c4/0x3b0 drivers/usb/core/driver.c:291
       call_driver_probe drivers/base/dd.c:-1 [inline]
       really_probe+0x267/0xaf0 drivers/base/dd.c:709
       __driver_probe_device+0x1ef/0x380 drivers/base/dd.c:871
       driver_probe_device+0x4f/0x240 drivers/base/dd.c:901
       __device_attach_driver+0x279/0x430 drivers/base/dd.c:1029
       bus_for_each_drv+0x258/0x2f0 drivers/base/bus.c:500
       __device_attach+0x2c5/0x450 drivers/base/dd.c:1101
       device_initial_probe+0xa1/0xd0 drivers/base/dd.c:1156
       bus_probe_device+0x12a/0x220 drivers/base/bus.c:613
       device_add+0x7e9/0xbb0 drivers/base/core.c:3706
       usb_new_device+0xa08/0x16f0 drivers/usb/core/hub.c:2695
       hub_port_connect drivers/usb/core/hub.c:5567 [inline]
       hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
       port_event drivers/usb/core/hub.c:5871 [inline]
       hub_event+0x2a1c/0x4f30 drivers/usb/core/hub.c:5953
       process_one_work kernel/workqueue.c:3314 [inline]
       process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3397
       worker_thread+0xa53/0xfc0 kernel/workqueue.c:3478
       kthread+0x389/0x470 kernel/kthread.c:436
       ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

other info that might help us debug this:

Chain exists of:
  fs_reclaim --> sk_lock-AF_INET6 --> &idev->mc_lock

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&idev->mc_lock);
                               lock(sk_lock-AF_INET6);
                               lock(&idev->mc_lock);
  lock(fs_reclaim);

 *** DEADLOCK ***

7 locks held by kworker/0:1/10:
 #0: ffff88801faf9d40 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline]
 #0: ffff88801faf9d40 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397
 #1: ffffc900000f7c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline]
 #1: ffffc900000f7c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397
 #2: ffff88802a42f1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline]
 #2: ffff88802a42f1d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x17f/0x4f30 drivers/usb/core/hub.c:5899
 #3: ffff888059c811d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline]
 #3: ffff888059c811d8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1076
 #4: ffff888043c331a0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline]
 #4: ffff888043c331a0 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1076
 #5: ffffffff8fdc8dc0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock_killable include/linux/rtnetlink.h:145 [inline]
 #5: ffffffff8fdc8dc0 (rtnl_mutex){+.+.}-{4:4}, at: register_netdev+0x18/0x60 net/core/dev.c:11536
 #6: ffff888079c97530 (&idev->mc_lock){+.+.}-{4:4}, at: __ipv6_dev_mc_inc+0x4e/0xa50 net/ipv6/mcast.c:943

stack backtrace:
CPU: 0 UID: 0 PID: 10 Comm: kworker/0:1 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Workqueue: usb_hub_wq hub_event
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_circular_bug+0x2e1/0x300 kernel/locking/lockdep.c:2043
 check_noncircular+0x12e/0x150 kernel/locking/lockdep.c:2175
 check_prev_add kernel/locking/lockdep.c:3165 [inline]
 check_prevs_add kernel/locking/lockdep.c:3284 [inline]
 validate_chain kernel/locking/lockdep.c:3908 [inline]
 __lock_acquire+0x15a5/0x2cf0 kernel/locking/lockdep.c:5237
 lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868
 __fs_reclaim_acquire mm/page_alloc.c:4320 [inline]
 fs_reclaim_acquire+0x71/0x100 mm/page_alloc.c:4334
 might_alloc include/linux/sched/mm.h:317 [inline]
 slab_pre_alloc_hook mm/slub.c:4521 [inline]
 slab_alloc_node mm/slub.c:4876 [inline]
 __kmalloc_cache_noprof+0x40/0x660 mm/slub.c:5415
 kmalloc_noprof include/linux/slab.h:950 [inline]
 kzalloc_noprof include/linux/slab.h:1188 [inline]
 mca_alloc net/ipv6/mcast.c:871 [inline]
 __ipv6_dev_mc_inc+0x44f/0xa50 net/ipv6/mcast.c:961
 ipv6_add_dev+0xe34/0x13a0 net/ipv6/addrconf.c:472
 addrconf_notify+0x771/0x1050 net/ipv6/addrconf.c:3662
 notifier_call_chain+0x1ad/0x3d0 kernel/notifier.c:85
 call_netdevice_notifiers_extack net/core/dev.c:2287 [inline]
 call_netdevice_notifiers net/core/dev.c:2301 [inline]
 register_netdevice+0x18c9/0x1ec0 net/core/dev.c:11461
 register_netdev+0x40/0x60 net/core/dev.c:11539
 rtl8150_probe+0x399/0x470 drivers/net/usb/rtl8150.c:942
 usb_probe_interface+0x659/0xc70 drivers/usb/core/driver.c:396
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x267/0xaf0 drivers/base/dd.c:709
 __driver_probe_device+0x1ef/0x380 drivers/base/dd.c:871
 driver_probe_device+0x4f/0x240 drivers/base/dd.c:901
 __device_attach_driver+0x279/0x430 drivers/base/dd.c:1029
 bus_for_each_drv+0x258/0x2f0 drivers/base/bus.c:500
 __device_attach+0x2c5/0x450 drivers/base/dd.c:1101
 device_initial_probe+0xa1/0xd0 drivers/base/dd.c:1156
 bus_probe_device+0x12a/0x220 drivers/base/bus.c:613
 device_add+0x7e9/0xbb0 drivers/base/core.c:3706
 usb_set_configuration+0x1a87/0x2110 drivers/usb/core/message.c:2268
 usb_generic_driver_probe+0x8d/0x150 drivers/usb/core/generic.c:250
 usb_probe_device+0x1c4/0x3b0 drivers/usb/core/driver.c:291
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x267/0xaf0 drivers/base/dd.c:709
 __driver_probe_device+0x1ef/0x380 drivers/base/dd.c:871
 driver_probe_device+0x4f/0x240 drivers/base/dd.c:901
 __device_attach_driver+0x279/0x430 drivers/base/dd.c:1029
 bus_for_each_drv+0x258/0x2f0 drivers/base/bus.c:500
 __device_attach+0x2c5/0x450 drivers/base/dd.c:1101
 device_initial_probe+0xa1/0xd0 drivers/base/dd.c:1156
 bus_probe_device+0x12a/0x220 drivers/base/bus.c:613
 device_add+0x7e9/0xbb0 drivers/base/core.c:3706
 usb_new_device+0xa08/0x16f0 drivers/usb/core/hub.c:2695
 hub_port_connect drivers/usb/core/hub.c:5567 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
 port_event drivers/usb/core/hub.c:5871 [inline]
 hub_event+0x2a1c/0x4f30 drivers/usb/core/hub.c:5953
 process_one_work kernel/workqueue.c:3314 [inline]
 process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3397
 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3478
 kthread+0x389/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
rtl8150 9-1:1.0: eth17: rtl8150 is detected
usb 9-1: USB disconnect, device number 13

Crashes (414):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/06/07 07:57 upstream 979c294509f9 cc095639 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root possible deadlock in __ipv6_dev_mc_inc
2026/06/06 04:35 upstream c10130c234c8 cc095639 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root possible deadlock in __ipv6_dev_mc_inc
2026/06/03 18:20 upstream ba3e43a9e601 234057e5 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root possible deadlock in __ipv6_dev_mc_inc
2026/06/02 22:16 upstream 6f3ed7fec72f 62fe1528 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root possible deadlock in __ipv6_dev_mc_inc
2026/05/10 19:14 upstream aa54b1d27fe0 29233ece .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root possible deadlock in __ipv6_dev_mc_inc
2026/03/12 10:29 upstream 80234b5ab240 4efadf07 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root possible deadlock in __ipv6_dev_mc_inc
2026/06/08 22:34 upstream 2d3090a8aeb5 656e94c6 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream possible deadlock in __ipv6_dev_mc_inc
2026/06/08 15:02 upstream 4549871118cf 656e94c6 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream possible deadlock in __ipv6_dev_mc_inc
2026/06/08 09:22 upstream 4549871118cf cc095639 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream possible deadlock in __ipv6_dev_mc_inc
2026/06/08 07:31 upstream 4549871118cf cc095639 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream possible deadlock in __ipv6_dev_mc_inc
2026/06/08 05:12 upstream 33d8d8ec31b5 cc095639 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream possible deadlock in __ipv6_dev_mc_inc
2026/06/07 20:10 upstream 33d8d8ec31b5 cc095639 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream possible deadlock in __ipv6_dev_mc_inc
2026/06/07 17:10 upstream 33d8d8ec31b5 cc095639 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream possible deadlock in __ipv6_dev_mc_inc
2026/06/06 02:33 upstream c10130c234c8 cc095639 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream possible deadlock in __ipv6_dev_mc_inc
2026/06/05 16:42 upstream ddd664bbff63 48b6c3fa .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream possible deadlock in __ipv6_dev_mc_inc
2026/06/05 00:26 upstream 9154c4af7829 197909be .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream possible deadlock in __ipv6_dev_mc_inc
2026/06/04 19:31 upstream ba3e43a9e601 197909be .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream possible deadlock in __ipv6_dev_mc_inc
2026/06/04 18:12 upstream ba3e43a9e601 197909be .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream possible deadlock in __ipv6_dev_mc_inc
2026/06/04 12:36 upstream ba3e43a9e601 197909be .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream possible deadlock in __ipv6_dev_mc_inc
2026/06/04 02:53 upstream ba3e43a9e601 197909be .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream possible deadlock in __ipv6_dev_mc_inc
2026/06/03 20:44 upstream ba3e43a9e601 234057e5 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream possible deadlock in __ipv6_dev_mc_inc
2026/06/03 03:24 upstream ba3e43a9e601 3c0d2131 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream possible deadlock in __ipv6_dev_mc_inc
2026/05/30 13:48 upstream f5e5d3509bff 6b4a8443 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream possible deadlock in __ipv6_dev_mc_inc
2026/05/28 22:44 upstream 8fde5d1d47f6 4624854e .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream possible deadlock in __ipv6_dev_mc_inc
2026/05/27 19:14 upstream eb3f4b7426cf cd9726af .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream possible deadlock in __ipv6_dev_mc_inc
2026/05/27 10:48 upstream eb3f4b7426cf cd9726af .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream possible deadlock in __ipv6_dev_mc_inc
2026/05/27 06:48 upstream d60ec36cab33 2b01f00e .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream possible deadlock in __ipv6_dev_mc_inc
2026/05/27 05:35 upstream d60ec36cab33 2b01f00e .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream possible deadlock in __ipv6_dev_mc_inc
2026/05/27 02:17 upstream d60ec36cab33 2b01f00e .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream possible deadlock in __ipv6_dev_mc_inc
2026/05/27 02:06 upstream d60ec36cab33 2b01f00e .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream possible deadlock in __ipv6_dev_mc_inc
2026/06/09 09:47 upstream 2d3090a8aeb5 656e94c6 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 possible deadlock in __ipv6_dev_mc_inc
2026/05/22 10:23 upstream 6779b50faa56 fbbd21af .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 possible deadlock in __ipv6_dev_mc_inc
2026/06/08 00:50 net 9772589b57e4 cc095639 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce possible deadlock in __ipv6_dev_mc_inc
2026/06/05 21:04 net 4aacf509e537 48b6c3fa .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce possible deadlock in __ipv6_dev_mc_inc
2026/06/05 06:28 net 4aacf509e537 197909be .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce possible deadlock in __ipv6_dev_mc_inc
2026/06/04 16:56 net c05fa14db43e 197909be .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce possible deadlock in __ipv6_dev_mc_inc
2026/06/06 11:32 net-next 2eb9a81a7f73 cc095639 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in __ipv6_dev_mc_inc
2026/06/04 08:44 net-next a87533a80831 197909be .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in __ipv6_dev_mc_inc
2026/06/03 23:52 net-next dfcc2ff12925 197909be .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in __ipv6_dev_mc_inc
2026/06/03 15:27 net-next dfcc2ff12925 234057e5 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in __ipv6_dev_mc_inc
2026/06/02 16:45 net-next 51e4eca2d360 62fe1528 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in __ipv6_dev_mc_inc
2026/06/02 02:17 net-next 0906c117f81c 1095583b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in __ipv6_dev_mc_inc
2026/06/01 18:52 net-next c2c0486c5680 8d8eeb3a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in __ipv6_dev_mc_inc
2026/05/31 10:11 net-next 841559836550 6b4a8443 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in __ipv6_dev_mc_inc
2026/05/30 11:00 net-next 841559836550 6b4a8443 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in __ipv6_dev_mc_inc
2026/05/30 09:22 net-next 841559836550 6b4a8443 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in __ipv6_dev_mc_inc
2026/05/30 06:27 net-next 841559836550 6b4a8443 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in __ipv6_dev_mc_inc
2026/05/29 20:00 net-next 841559836550 6b4a8443 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in __ipv6_dev_mc_inc
2026/05/29 08:51 net-next 9a82e387e27a 4624854e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in __ipv6_dev_mc_inc
2026/05/28 16:47 net-next 0cf905cb9a12 9a5a7e5e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in __ipv6_dev_mc_inc
2026/05/26 22:58 net-next 18b9f739d3f2 2b01f00e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in __ipv6_dev_mc_inc
2026/05/26 15:51 net-next 3baa7ba4ab98 a3e47276 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in __ipv6_dev_mc_inc
2026/03/30 05:39 linux-next 3b058d1aeeef 356bdfc9 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce possible deadlock in __ipv6_dev_mc_inc
2026/03/21 16:19 linux-next 785f0eb2f85d 5b92003d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root possible deadlock in __ipv6_dev_mc_inc
* Struck through repros no longer work on HEAD.