syzbot

INFO: task syz.1.4491:22653 blocked for more than 143 seconds.
      Tainted: G     U              6.16.0-rc4-syzkaller-00123-g4c06e63b9203 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.4491      state:D stack:28264 pid:22653 tgid:22650 ppid:5850   task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5396 [inline]
 __schedule+0x116a/0x5de0 kernel/sched/core.c:6785
 __schedule_loop kernel/sched/core.c:6863 [inline]
 schedule+0xe7/0x3a0 kernel/sched/core.c:6878
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6935
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x6c7/0xb90 kernel/locking/mutex.c:747
 nfsd_nl_version_get_doit+0x18a/0x800 fs/nfsd/nfsctl.c:1847
 genl_family_rcv_msg_doit+0x209/0x2f0 net/netlink/genetlink.c:1115
 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
 genl_rcv_msg+0x55c/0x800 net/netlink/genetlink.c:1210
 netlink_rcv_skb+0x158/0x420 net/netlink/af_netlink.c:2534
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline]
 netlink_unicast+0x53a/0x7f0 net/netlink/af_netlink.c:1339
 netlink_sendmsg+0x8d1/0xdd0 net/netlink/af_netlink.c:1883
 sock_sendmsg_nosec net/socket.c:712 [inline]
 __sock_sendmsg net/socket.c:727 [inline]
 ____sys_sendmsg+0xa98/0xc70 net/socket.c:2566
 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2620
 __sys_sendmsg+0x16d/0x220 net/socket.c:2652
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x490 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fedd2d8e929
RSP: 002b:00007fedd0bf6038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fedd2fb6080 RCX: 00007fedd2d8e929
RDX: 0000000000000800 RSI: 0000200000000140 RDI: 0000000000000003
RBP: 00007fedd2e10b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007fedd2fb6080 R15: 00007ffe3fe0da68
 </TASK>
INFO: lockdep is turned off.
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Tainted: G     U              6.16.0-rc4-syzkaller-00123-g4c06e63b9203 #0 PREEMPT(full) 
Tainted: [U]=USER
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline]
 watchdog+0xf70/0x12c0 kernel/hung_task.c:470
 kthread+0x3c5/0x780 kernel/kthread.c:464
 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 21029 Comm: kworker/u8:9 Tainted: G     U              6.16.0-rc4-syzkaller-00123-g4c06e63b9203 #0 PREEMPT(full) 
Tainted: [U]=USER
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: events_unbound cfg80211_wiphy_work
RIP: 0010:kasan_save_stack+0x49/0x60 mm/kasan/common.c:49
Code: 02 00 00 48 89 e3 48 89 df f3 48 ab 48 89 df e8 7d d2 85 ff 44 89 e1 89 ea 48 89 df 89 c6 e8 9e 7f e9 02 48 81 c4 00 02 00 00 <5b> 5d 41 5c c3 cc cc cc cc 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f
RSP: 0018:ffffc9000b9cfa18 EFLAGS: 00000286
RAX: 00000000040a0272 RBX: ffffc9000b9cf818 RCX: ffff88805b1ce050
RDX: 00000000a0d840f8 RSI: ffffffff812c009a RDI: 000000003b998927
RBP: 0000000000000000 R08: ffffffff9138dbc8 R09: ffff88823ae52410
R10: ffffc9000b9cf6e8 R11: 0000000000002c00 R12: 0000000000000001
R13: 0000000000212110 R14: ffffea0001b28300 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff888124822000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4e434e7d60 CR3: 000000000e382000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:576
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x51/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2381 [inline]
 slab_free mm/slub.c:4643 [inline]
 kmem_cache_free+0x2d1/0x4d0 mm/slub.c:4745
 skb_kfree_head net/core/skbuff.c:1046 [inline]
 skb_kfree_head net/core/skbuff.c:1043 [inline]
 skb_free_head+0x1b7/0x210 net/core/skbuff.c:1060
 skb_release_data+0x776/0x9c0 net/core/skbuff.c:1087
 skb_release_all net/core/skbuff.c:1152 [inline]
 __kfree_skb net/core/skbuff.c:1166 [inline]
 sk_skb_reason_drop+0x129/0x1a0 net/core/skbuff.c:1204
 kfree_skb_reason include/linux/skbuff.h:1275 [inline]
 kfree_skb include/linux/skbuff.h:1284 [inline]
 ieee80211_iface_work+0x434/0x1020 net/mac80211/iface.c:1724
 cfg80211_wiphy_work+0x3dc/0x550 net/wireless/core.c:435
 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238
 process_scheduled_works kernel/workqueue.c:3321 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402
 kthread+0x3c5/0x780 kernel/kthread.c:464
 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
vkms_vblank_simulate: vblank timer overrun