possible deadlock in kernfs_link_sibling (2)

Status: upstream: reported on 2026/03/17 17:33
Subsystems: kernfs
Labels: prio:low
[Documentation on labels]
Reported-by: syzbot+dd764a450d93885d847f@syzkaller.appspotmail.com
First crash: 148d, last: 21m
▶ ▼ ✨ AI Jobs (2)
ID Workflow Result Correct Bug Created Started Finished Revision
165765ce assessment-security DenialOfService: ❌ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ ❓ possible deadlock in kernfs_link_sibling (2) 2026/05/31 17:24 2026/05/31 17:24 2026/05/31 18:25 6b4a8443
5b51ca2f assessment-security 💥 possible deadlock in kernfs_link_sibling (2) 2026/05/15 05:52 2026/05/15 05:52 2026/05/15 05:53 6ccb967e
▶ ▼ Discussions (4)
Title Replies (including bot) Last reply
[syzbot] Monthly kernfs report (May 2026) 0 (1) 2026/05/31 04:32
[syzbot] Monthly kernfs report (Apr 2026) 0 (1) 2026/04/29 20:32
Re: [syzbot] possible deadlock in kernfs_link_sibling (2) 1 (1) 2026/03/18 15:23
[syzbot] [kernfs?] possible deadlock in kernfs_link_sibling (2) 0 (1) 2026/03/17 17:33
▶ ▼ Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream possible deadlock in kernfs_link_sibling kernfs 4 30 306d 338d 0/29 closed as invalid on 2025/10/25 16:44

Sample crash report:
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.0.1994/12634 is trying to acquire lock:
ffff88801caf7a10 (&root->kernfs_iattr_rwsem){++++}-{4:4}, at: kernfs_link_sibling+0x555/0x850 fs/kernfs/dir.c:411

but task is already holding lock:
ffff88801caf7980 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_add_one+0x38/0xaa0 fs/kernfs/dir.c:825

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #9 (&root->kernfs_rwsem){++++}-{4:4}:
       lock_acquire kernel/locking/lockdep.c:5868 [inline]
       lock_acquire+0x1b9/0x370 kernel/locking/lockdep.c:5825
       down_write+0x8b/0x1f0 kernel/locking/rwsem.c:1631
       kernfs_add_one+0x38/0xaa0 fs/kernfs/dir.c:825
       kernfs_create_dir_ns+0x157/0x2b0 fs/kernfs/dir.c:1130
       internal_create_group+0x36f/0xfb0 fs/sysfs/group.c:176
       cpuhp_invoke_callback+0x3b4/0x9a0 kernel/cpu.c:194
       cpuhp_issue_call+0x1b8/0x970 kernel/cpu.c:2354
       __cpuhp_setup_state_cpuslocked+0x431/0x880 kernel/cpu.c:2507
       __cpuhp_setup_state+0xf4/0x2f0 kernel/cpu.c:2536
       do_one_initcall+0x11d/0x700 init/main.c:1347
       do_initcall_level init/main.c:1409 [inline]
       do_initcalls init/main.c:1425 [inline]
       do_basic_setup init/main.c:1445 [inline]
       kernel_init_freeable+0x6ea/0x7b0 init/main.c:1658
       kernel_init+0x1f/0x1e0 init/main.c:1548
       ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

-> #8 (cpuhp_state_mutex){+.+.}-{4:4}:

-> #7 (cpu_hotplug_lock){++++}-{0:0}:
       lock_acquire kernel/locking/lockdep.c:5868 [inline]
       lock_acquire+0x1b9/0x370 kernel/locking/lockdep.c:5825
       percpu_down_read_internal include/linux/percpu-rwsem.h:53 [inline]
       percpu_down_read include/linux/percpu-rwsem.h:77 [inline]
       cpus_read_lock+0x42/0x170 kernel/cpu.c:490
       static_key_slow_inc+0x12/0x30 kernel/jump_label.c:190
       nbd_reconnect_socket drivers/block/nbd.c:1379 [inline]
       nbd_genl_reconfigure+0xd82/0x1a00 drivers/block/nbd.c:2468
       genl_family_rcv_msg_doit+0x214/0x300 net/netlink/genetlink.c:1114
       genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline]
       genl_rcv_msg+0x560/0x800 net/netlink/genetlink.c:1209
       netlink_rcv_skb+0x159/0x420 net/netlink/af_netlink.c:2556
       genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218
       netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
       netlink_unicast+0x585/0x850 net/netlink/af_netlink.c:1345
       netlink_sendmsg+0x8b0/0xda0 net/netlink/af_netlink.c:1900
       sock_sendmsg_nosec net/socket.c:775 [inline]
       __sock_sendmsg net/socket.c:790 [inline]
       ____sys_sendmsg+0xa4d/0xbe0 net/socket.c:2684
       ___sys_sendmsg+0x190/0x1e0 net/socket.c:2738
       __sys_sendmsg+0x160/0x210 net/socket.c:2770
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #6 (&nsock->tx_lock){+.+.}-{4:4}:
       lock_acquire kernel/locking/lockdep.c:5868 [inline]
       lock_acquire+0x1b9/0x370 kernel/locking/lockdep.c:5825
       __mutex_lock_common kernel/locking/mutex.c:646 [inline]
       __mutex_lock+0x1a4/0x1bd0 kernel/locking/mutex.c:821
       nbd_handle_cmd drivers/block/nbd.c:1143 [inline]
       nbd_queue_rq+0x428/0x1080 drivers/block/nbd.c:1207
       blk_mq_dispatch_rq_list+0x422/0x1e70 block/blk-mq.c:2117
       __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+0xcea/0x1620 block/blk-mq-sched.c:307
       blk_mq_sched_dispatch_requests+0xd7/0x1c0 block/blk-mq-sched.c:329
       blk_mq_run_work_fn+0x135/0x380 block/blk-mq.c:2531
       process_one_work+0xa23/0x1940 kernel/workqueue.c:3322
       process_scheduled_works kernel/workqueue.c:3405 [inline]
       worker_thread+0x5ef/0xe50 kernel/workqueue.c:3486
       kthread+0x370/0x450 kernel/kthread.c:436
       ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

-> #5 (&cmd->lock){+.+.}-{4:4}:
       lock_acquire kernel/locking/lockdep.c:5868 [inline]
       lock_acquire+0x1b9/0x370 kernel/locking/lockdep.c:5825
       __mutex_lock_common kernel/locking/mutex.c:646 [inline]
       __mutex_lock+0x1a4/0x1bd0 kernel/locking/mutex.c:821
       nbd_queue_rq+0xba/0x1080 drivers/block/nbd.c:1199
       blk_mq_dispatch_rq_list+0x422/0x1e70 block/blk-mq.c:2117
       __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+0xcea/0x1620 block/blk-mq-sched.c:307
       blk_mq_sched_dispatch_requests+0xd7/0x1c0 block/blk-mq-sched.c:329
       blk_mq_run_work_fn+0x135/0x380 block/blk-mq.c:2531
       process_one_work+0xa23/0x1940 kernel/workqueue.c:3322
       process_scheduled_works kernel/workqueue.c:3405 [inline]
       worker_thread+0x5ef/0xe50 kernel/workqueue.c:3486
       kthread+0x370/0x450 kernel/kthread.c:436
       ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

-> #4 (set->srcu){.+.+}-{0:0}:
       lock_sync kernel/locking/lockdep.c:5916 [inline]
       lock_sync+0x9d/0x110 kernel/locking/lockdep.c:5904
       srcu_lock_sync include/linux/srcu.h:199 [inline]
       __synchronize_srcu+0xa2/0x300 kernel/rcu/srcutree.c:1481
       blk_mq_wait_quiesce_done block/blk-mq.c:284 [inline]
       blk_mq_wait_quiesce_done block/blk-mq.c:281 [inline]
       blk_mq_quiesce_queue block/blk-mq.c:304 [inline]
       blk_mq_quiesce_queue+0x149/0x1c0 block/blk-mq.c:299
       elevator_switch+0x17b/0x7e0 block/elevator.c:576
       elevator_change+0x352/0x530 block/elevator.c:681
       elevator_set_default+0x29e/0x360 block/elevator.c:754
       blk_register_queue+0x48e/0x630 block/blk-sysfs.c:992
       __add_disk+0x73f/0xe40 block/genhd.c:524
       add_disk_fwnode+0x118/0x480 block/genhd.c:593
       add_disk include/linux/blkdev.h:800 [inline]
       nbd_dev_add+0x77a/0xb10 drivers/block/nbd.c:2021
       nbd_init+0x291/0x2b0 drivers/block/nbd.c:2729
       do_one_initcall+0x11d/0x700 init/main.c:1347
       do_initcall_level init/main.c:1409 [inline]
       do_initcalls init/main.c:1425 [inline]
       do_basic_setup init/main.c:1445 [inline]
       kernel_init_freeable+0x6ea/0x7b0 init/main.c:1658
       kernel_init+0x1f/0x1e0 init/main.c:1548
       ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

-> #3 (&q->elevator_lock){+.+.}-{4:4}:
       lock_acquire kernel/locking/lockdep.c:5868 [inline]
       lock_acquire+0x1b9/0x370 kernel/locking/lockdep.c:5825
       __mutex_lock_common kernel/locking/mutex.c:646 [inline]
       __mutex_lock+0x1a4/0x1bd0 kernel/locking/mutex.c:821
       elevator_change+0x1bc/0x530 block/elevator.c:679
       elevator_set_none+0x92/0xf0 block/elevator.c:769
       blk_mq_elv_switch_none block/blk-mq.c:5101 [inline]
       __blk_mq_update_nr_hw_queues block/blk-mq.c:5146 [inline]
       blk_mq_update_nr_hw_queues+0x4c1/0x15f0 block/blk-mq.c:5211
       nbd_start_device+0x1a6/0xbd0 drivers/block/nbd.c:1526
       nbd_genl_connect+0xff2/0x1a40 drivers/block/nbd.c:2276
       genl_family_rcv_msg_doit+0x214/0x300 net/netlink/genetlink.c:1114
       genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline]
       genl_rcv_msg+0x560/0x800 net/netlink/genetlink.c:1209
       netlink_rcv_skb+0x159/0x420 net/netlink/af_netlink.c:2556
       genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218
       netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
       netlink_unicast+0x585/0x850 net/netlink/af_netlink.c:1345
       netlink_sendmsg+0x8b0/0xda0 net/netlink/af_netlink.c:1900
       sock_sendmsg_nosec net/socket.c:775 [inline]
       __sock_sendmsg net/socket.c:790 [inline]
       ____sys_sendmsg+0xa4d/0xbe0 net/socket.c:2684
       ___sys_sendmsg+0x190/0x1e0 net/socket.c:2738
       __sys_sendmsg+0x160/0x210 net/socket.c:2770
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #2 (&q->q_usage_counter(io)#51){++++}-{0:0}:
       lock_acquire kernel/locking/lockdep.c:5868 [inline]
       lock_acquire+0x1b9/0x370 kernel/locking/lockdep.c:5825
       blk_alloc_queue+0x610/0x790 block/blk-core.c:504
       blk_mq_alloc_queue+0x174/0x290 block/blk-mq.c:4420
       __blk_mq_alloc_disk+0x29/0x120 block/blk-mq.c:4467
       nbd_dev_add+0x492/0xb10 drivers/block/nbd.c:1991
       nbd_init+0x291/0x2b0 drivers/block/nbd.c:2729
       do_one_initcall+0x11d/0x700 init/main.c:1347
       do_initcall_level init/main.c:1409 [inline]
       do_initcalls init/main.c:1425 [inline]
       do_basic_setup init/main.c:1445 [inline]
       kernel_init_freeable+0x6ea/0x7b0 init/main.c:1658
       kernel_init+0x1f/0x1e0 init/main.c:1548
       ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

-> #1 (fs_reclaim){+.+.}-{0:0}:
       lock_acquire kernel/locking/lockdep.c:5868 [inline]
       lock_acquire+0x1b9/0x370 kernel/locking/lockdep.c:5825
       __fs_reclaim_acquire mm/page_alloc.c:4329 [inline]
       fs_reclaim_acquire+0xc4/0x100 mm/page_alloc.c:4343
       might_alloc include/linux/sched/mm.h:317 [inline]
       slab_pre_alloc_hook mm/slub.c:4565 [inline]
       slab_alloc_node mm/slub.c:4925 [inline]
       kmem_cache_alloc_noprof+0x63/0x6a0 mm/slub.c:4959
       __kernfs_iattrs+0x126/0x450 fs/kernfs/inode.c:36
       kernfs_iattrs fs/kernfs/inode.c:60 [inline]
       __kernfs_setattr+0x4d/0x3c0 fs/kernfs/inode.c:73
       kernfs_iop_setattr+0xda/0x130 fs/kernfs/inode.c:127
       notify_change+0xb25/0x1330 fs/attr.c:556
       do_truncate+0x1df/0x240 fs/open.c:68
       handle_truncate fs/namei.c:4305 [inline]
       do_open fs/namei.c:4704 [inline]
       path_openat+0x370f/0x4280 fs/namei.c:4863
       do_file_open+0x20e/0x430 fs/namei.c:4892
       do_sys_openat2+0x10f/0x1e0 fs/open.c:1368
       do_sys_open fs/open.c:1374 [inline]
       __do_sys_openat fs/open.c:1390 [inline]
       __se_sys_openat fs/open.c:1385 [inline]
       __x64_sys_openat+0x12d/0x210 fs/open.c:1385
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (&root->kernfs_iattr_rwsem){++++}-{4:4}:
       check_prev_add+0xeb/0xe60 kernel/locking/lockdep.c:3165
       check_prevs_add kernel/locking/lockdep.c:3284 [inline]
       validate_chain kernel/locking/lockdep.c:3908 [inline]
       __lock_acquire+0x136c/0x1a40 kernel/locking/lockdep.c:5237
       lock_acquire kernel/locking/lockdep.c:5868 [inline]
       lock_acquire+0x1b9/0x370 kernel/locking/lockdep.c:5825
       down_write+0x8b/0x1f0 kernel/locking/rwsem.c:1631
       kernfs_link_sibling+0x555/0x850 fs/kernfs/dir.c:411
       kernfs_add_one+0x1e7/0xaa0 fs/kernfs/dir.c:844
       kernfs_create_dir_ns+0x157/0x2b0 fs/kernfs/dir.c:1130
       sysfs_create_dir_ns+0x13a/0x2b0 fs/sysfs/dir.c:59
       create_dir lib/kobject.c:73 [inline]
       kobject_add_internal+0x2c8/0x930 lib/kobject.c:240
       kobject_add_varg lib/kobject.c:374 [inline]
       kobject_add+0x16a/0x1e0 lib/kobject.c:426
       elv_register_queue block/elevator.c:463 [inline]
       elevator_change_done+0x252/0x650 block/elevator.c:643
       elv_update_nr_hw_queues+0x1ea/0x2b0 block/elevator.c:716
       blk_mq_elv_switch_back block/blk-mq.c:5056 [inline]
       __blk_mq_update_nr_hw_queues block/blk-mq.c:5186 [inline]
       blk_mq_update_nr_hw_queues+0x900/0x15f0 block/blk-mq.c:5211
       nbd_start_device+0x1a6/0xbd0 drivers/block/nbd.c:1526
       nbd_genl_connect+0xff2/0x1a40 drivers/block/nbd.c:2276
       genl_family_rcv_msg_doit+0x214/0x300 net/netlink/genetlink.c:1114
       genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline]
       genl_rcv_msg+0x560/0x800 net/netlink/genetlink.c:1209
       netlink_rcv_skb+0x159/0x420 net/netlink/af_netlink.c:2556
       genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218
       netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
       netlink_unicast+0x585/0x850 net/netlink/af_netlink.c:1345
       netlink_sendmsg+0x8b0/0xda0 net/netlink/af_netlink.c:1900
       sock_sendmsg_nosec net/socket.c:775 [inline]
       __sock_sendmsg net/socket.c:790 [inline]
       ____sys_sendmsg+0xa4d/0xbe0 net/socket.c:2684
       ___sys_sendmsg+0x190/0x1e0 net/socket.c:2738
       __sys_sendmsg+0x160/0x210 net/socket.c:2770
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

other info that might help us debug this:

Chain exists of:
  &root->kernfs_iattr_rwsem --> cpuhp_state_mutex --> &root->kernfs_rwsem

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&root->kernfs_rwsem);
                               lock(cpuhp_state_mutex);
                               lock(&root->kernfs_rwsem);
  lock(&root->kernfs_iattr_rwsem);

 *** DEADLOCK ***

5 locks held by syz.0.1994/12634:
 #0: ffffffff90b4a6c8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
 #1: ffffffff90b4a780 (genl_mutex){+.+.}-{4:4}, at: genl_lock net/netlink/genetlink.c:35 [inline]
 #1: ffffffff90b4a780 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:60 [inline]
 #1: ffffffff90b4a780 (genl_mutex){+.+.}-{4:4}, at: genl_op_lock net/netlink/genetlink.c:57 [inline]
 #1: ffffffff90b4a780 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x57b/0x800 net/netlink/genetlink.c:1208
 #2: ffff88802750f1c0 (&set->update_nr_hwq_lock){++++}-{4:4}, at: blk_mq_update_nr_hw_queues+0x9d/0x15f0 block/blk-mq.c:5209
 #3: ffff88802750f0d0 (&set->tag_list_lock){+.+.}-{4:4}, at: blk_mq_update_nr_hw_queues+0xb0/0x15f0 block/blk-mq.c:5210
 #4: ffff88801caf7980 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_add_one+0x38/0xaa0 fs/kernfs/dir.c:825

stack backtrace:
CPU: 0 UID: 0 PID: 12634 Comm: syz.0.1994 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/10/2026
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 print_circular_bug.cold+0x178/0x1c7 kernel/locking/lockdep.c:2043
 check_noncircular+0x146/0x160 kernel/locking/lockdep.c:2175
 check_prev_add+0xeb/0xe60 kernel/locking/lockdep.c:3165
 check_prevs_add kernel/locking/lockdep.c:3284 [inline]
 validate_chain kernel/locking/lockdep.c:3908 [inline]
 __lock_acquire+0x136c/0x1a40 kernel/locking/lockdep.c:5237
 lock_acquire kernel/locking/lockdep.c:5868 [inline]
 lock_acquire+0x1b9/0x370 kernel/locking/lockdep.c:5825
 down_write+0x8b/0x1f0 kernel/locking/rwsem.c:1631
 kernfs_link_sibling+0x555/0x850 fs/kernfs/dir.c:411
 kernfs_add_one+0x1e7/0xaa0 fs/kernfs/dir.c:844
 kernfs_create_dir_ns+0x157/0x2b0 fs/kernfs/dir.c:1130
 sysfs_create_dir_ns+0x13a/0x2b0 fs/sysfs/dir.c:59
 create_dir lib/kobject.c:73 [inline]
 kobject_add_internal+0x2c8/0x930 lib/kobject.c:240
 kobject_add_varg lib/kobject.c:374 [inline]
 kobject_add+0x16a/0x1e0 lib/kobject.c:426
 elv_register_queue block/elevator.c:463 [inline]
 elevator_change_done+0x252/0x650 block/elevator.c:643
 elv_update_nr_hw_queues+0x1ea/0x2b0 block/elevator.c:716
 blk_mq_elv_switch_back block/blk-mq.c:5056 [inline]
 __blk_mq_update_nr_hw_queues block/blk-mq.c:5186 [inline]
 blk_mq_update_nr_hw_queues+0x900/0x15f0 block/blk-mq.c:5211
 nbd_start_device+0x1a6/0xbd0 drivers/block/nbd.c:1526
 nbd_genl_connect+0xff2/0x1a40 drivers/block/nbd.c:2276
 genl_family_rcv_msg_doit+0x214/0x300 net/netlink/genetlink.c:1114
 genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline]
 genl_rcv_msg+0x560/0x800 net/netlink/genetlink.c:1209
 netlink_rcv_skb+0x159/0x420 net/netlink/af_netlink.c:2556
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218
 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
 netlink_unicast+0x585/0x850 net/netlink/af_netlink.c:1345
 netlink_sendmsg+0x8b0/0xda0 net/netlink/af_netlink.c:1900
 sock_sendmsg_nosec net/socket.c:775 [inline]
 __sock_sendmsg net/socket.c:790 [inline]
 ____sys_sendmsg+0xa4d/0xbe0 net/socket.c:2684
 ___sys_sendmsg+0x190/0x1e0 net/socket.c:2738
 __sys_sendmsg+0x160/0x210 net/socket.c:2770
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7efe96d9de59
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:00007efe97c42028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007efe97025fa0 RCX: 00007efe96d9de59
RDX: 0000000000000004 RSI: 0000200000001ac0 RDI: 0000000000000038
RBP: 00007efe96e33e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007efe97026038 R14: 00007efe97025fa0 R15: 00007ffd37a53128
 </TASK>

Crashes (7064):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/07/13 00:42 upstream 44696aa3a489 d78ea535 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root possible deadlock in kernfs_link_sibling
2026/06/11 13:35 upstream 9716c086c8e8 d93a6ab6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root possible deadlock in kernfs_link_sibling
2026/06/02 16:56 upstream 6f3ed7fec72f 62fe1528 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto possible deadlock in kernfs_link_sibling
2026/06/02 11:21 upstream 6f3ed7fec72f 62fe1528 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root possible deadlock in kernfs_link_sibling
2026/05/31 02:07 upstream 174914ea5513 6b4a8443 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root possible deadlock in kernfs_link_sibling
2026/05/13 06:11 upstream c21b90f77687 a0949470 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root possible deadlock in kernfs_link_sibling
2026/04/25 15:12 upstream 27d128c1cff6 9c2d0995 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root possible deadlock in kernfs_link_sibling
2026/03/17 04:22 upstream 2d1373e4246d 0737c18f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root possible deadlock in kernfs_link_sibling
2026/07/25 07:41 upstream 0ce37745d4bf 4a865b71 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream possible deadlock in kernfs_link_sibling
2026/03/13 17:29 upstream 0257f64bdac7 351cb5cf .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream possible deadlock in kernfs_link_sibling
2026/07/23 18:01 upstream 4539944e5151 4a865b71 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 possible deadlock in kernfs_link_sibling
2026/08/09 16:40 net dd057113ac7b 5d63f80b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce possible deadlock in kernfs_link_sibling
2026/08/09 11:21 net dd057113ac7b 5d63f80b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce possible deadlock in kernfs_link_sibling
2026/08/09 05:05 net dd057113ac7b 5d63f80b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce possible deadlock in kernfs_link_sibling
2026/08/09 03:30 net dd057113ac7b 5d63f80b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce possible deadlock in kernfs_link_sibling
2026/08/08 23:27 net dd057113ac7b 5d63f80b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce possible deadlock in kernfs_link_sibling
2026/08/08 15:20 net dd057113ac7b 5d63f80b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce possible deadlock in kernfs_link_sibling
2026/08/08 09:17 net 3dbb44d88b1e e4ef95d6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce possible deadlock in kernfs_link_sibling
2026/08/08 07:35 net 3dbb44d88b1e e4ef95d6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce possible deadlock in kernfs_link_sibling
2026/08/08 06:32 net 3dbb44d88b1e e4ef95d6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce possible deadlock in kernfs_link_sibling
2026/08/08 05:27 net 3dbb44d88b1e e4ef95d6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce possible deadlock in kernfs_link_sibling
2026/08/08 03:46 net 3dbb44d88b1e e4ef95d6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce possible deadlock in kernfs_link_sibling
2026/08/08 02:31 net 3dbb44d88b1e e4ef95d6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce possible deadlock in kernfs_link_sibling
2026/08/07 16:21 net 594d90519502 e4ef95d6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce possible deadlock in kernfs_link_sibling
2026/08/07 16:00 net 594d90519502 e4ef95d6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce possible deadlock in kernfs_link_sibling
2026/08/07 10:30 net 594d90519502 c38879ea .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce possible deadlock in kernfs_link_sibling
2026/08/07 07:06 net 594d90519502 c38879ea .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce possible deadlock in kernfs_link_sibling
2026/08/07 04:55 net 594d90519502 c38879ea .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce possible deadlock in kernfs_link_sibling
2026/08/07 02:57 net 7e2d693af0d4 c38879ea .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce possible deadlock in kernfs_link_sibling
2026/08/07 00:00 net 7e2d693af0d4 c38879ea .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce possible deadlock in kernfs_link_sibling
2026/08/06 22:02 net 7e2d693af0d4 c38879ea .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce possible deadlock in kernfs_link_sibling
2026/08/06 14:55 net 7e2d693af0d4 c38879ea .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce possible deadlock in kernfs_link_sibling
2026/08/06 11:05 net 9113e98eb7e3 cd5b1963 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce possible deadlock in kernfs_link_sibling
2026/08/06 09:43 net 9113e98eb7e3 cd5b1963 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce possible deadlock in kernfs_link_sibling
2026/08/06 02:37 net 9113e98eb7e3 cd5b1963 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce possible deadlock in kernfs_link_sibling
2026/08/06 01:15 net 9113e98eb7e3 cd5b1963 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce possible deadlock in kernfs_link_sibling
2026/08/05 23:37 net aa2e13ae8d3c cd5b1963 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce possible deadlock in kernfs_link_sibling
2026/08/05 19:26 net aa2e13ae8d3c b3eac40e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce possible deadlock in kernfs_link_sibling
2026/08/05 18:00 net aa2e13ae8d3c b3eac40e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce possible deadlock in kernfs_link_sibling
2026/08/05 13:35 net aa2e13ae8d3c b3eac40e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce possible deadlock in kernfs_link_sibling
2026/08/05 10:41 net aa2e13ae8d3c b3eac40e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce possible deadlock in kernfs_link_sibling
2026/08/09 13:12 net-next 001b5d347d8b 5d63f80b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in kernfs_link_sibling
2026/08/09 10:40 net-next 001b5d347d8b 5d63f80b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in kernfs_link_sibling
2026/08/09 09:31 net-next 001b5d347d8b 5d63f80b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in kernfs_link_sibling
2026/08/09 07:14 net-next 001b5d347d8b 5d63f80b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in kernfs_link_sibling
2026/08/08 20:12 net-next 001b5d347d8b 5d63f80b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in kernfs_link_sibling
2026/08/08 16:48 net-next 001b5d347d8b 5d63f80b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in kernfs_link_sibling
2026/08/08 10:23 net-next 3a30302b9391 e4ef95d6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in kernfs_link_sibling
2026/08/08 07:58 net-next 3a30302b9391 e4ef95d6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in kernfs_link_sibling
2026/08/07 22:44 net-next 4fa4977a0d90 e4ef95d6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in kernfs_link_sibling
2026/08/07 19:58 net-next 4fa4977a0d90 e4ef95d6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in kernfs_link_sibling
2026/08/07 18:17 net-next 4fa4977a0d90 e4ef95d6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in kernfs_link_sibling
2026/08/07 08:40 net-next 4fa4977a0d90 c38879ea .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in kernfs_link_sibling
2026/08/06 18:28 net-next f37228367375 c38879ea .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in kernfs_link_sibling
2026/08/06 04:38 net-next cb59bfd419d0 cd5b1963 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in kernfs_link_sibling
2026/08/05 15:01 net-next a23b36233d41 b3eac40e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in kernfs_link_sibling
2026/05/30 14:10 linux-next f7af91adc230 6b4a8443 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce possible deadlock in kernfs_link_sibling
2026/05/18 02:03 linux-next e98d21c170b0 de5aae85 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root possible deadlock in kernfs_link_sibling
2026/06/25 00:28 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 92e3f6ef4ffb cfa969bf .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 possible deadlock in kernfs_link_sibling
* Struck through repros no longer work on HEAD.