syzbot

kvm: exiting hardware virtualization
==================================================================
BUG: KASAN: use-after-free in __mutex_waiter_is_first kernel/locking/mutex.c:191 [inline]
BUG: KASAN: use-after-free in __mutex_lock_common+0xc85/0x2390 kernel/locking/mutex.c:671
Read of size 8 at addr ffff88807ad4b160 by task init/17280

CPU: 0 PID: 17280 Comm: init Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
 print_address_description+0x60/0x2d0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:434 [inline]
 kasan_report+0xdf/0x130 mm/kasan/report.c:451
 __mutex_waiter_is_first kernel/locking/mutex.c:191 [inline]
 __mutex_lock_common+0xc85/0x2390 kernel/locking/mutex.c:671
 __mutex_lock kernel/locking/mutex.c:729 [inline]
 mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
 device_lock include/linux/device.h:764 [inline]
 device_shutdown+0x1fc/0x5e0 drivers/base/core.c:4549
 kernel_shutdown_prepare kernel/reboot.c:266 [inline]
 kernel_power_off+0x4f/0xb0 kernel/reboot.c:291
 __do_sys_reboot kernel/reboot.c:366 [inline]
 __se_sys_reboot+0x391/0x3b0 kernel/reboot.c:312
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f6a91dbd8d3
Code: ff 45 31 c9 6a 13 45 31 c0 31 c9 e8 67 8b f8 ff 48 83 c4 18 c3 66 90 89 fa be 69 19 12 28 bf ad de e1 fe b8 a9 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 05 c3 0f 1f 40 00 48 8b 15 f1 24 0d 00 f7 d8
RSP: 002b:00007ffed2c9e428 EFLAGS: 00000246 ORIG_RAX: 00000000000000a9
RAX: ffffffffffffffda RBX: 000000000000000c RCX: 00007f6a91dbd8d3
RDX: 000000004321fedc RSI: 0000000028121969 RDI: 00000000fee1dead
RBP: 000000004321fedc R08: 0000000000000000 R09: 0000000000000000
R10: 00007ffed2c9e400 R11: 0000000000000246 R12: 00007f6a91f60490
R13: 00007ffed2c9e47c R14: 00007f6a91f98000 R15: 000055a072b1fd98
 </TASK>

Allocated by task 13540:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:434 [inline]
 ____kasan_kmalloc mm/kasan/common.c:513 [inline]
 __kasan_kmalloc+0xb5/0xf0 mm/kasan/common.c:522
 kmalloc include/linux/slab.h:607 [inline]
 kzalloc include/linux/slab.h:738 [inline]
 nsim_bus_dev_new drivers/net/netdevsim/bus.c:408 [inline]
 new_device_store+0x194/0x740 drivers/net/netdevsim/bus.c:302
 kernfs_fop_write_iter+0x379/0x4c0 fs/kernfs/file.c:296
 call_write_iter include/linux/fs.h:2173 [inline]
 new_sync_write fs/read_write.c:507 [inline]
 vfs_write+0x712/0xd00 fs/read_write.c:594
 ksys_write+0x14d/0x250 fs/read_write.c:647
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

Freed by task 16989:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:46
 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360
 ____kasan_slab_free+0xd5/0x110 mm/kasan/common.c:366
 kasan_slab_free include/linux/kasan.h:230 [inline]
 slab_free_hook mm/slub.c:1710 [inline]
 slab_free_freelist_hook+0xea/0x170 mm/slub.c:1736
 slab_free mm/slub.c:3504 [inline]
 kfree+0xef/0x2a0 mm/slub.c:4564
 nsim_bus_dev_del drivers/net/netdevsim/bus.c:457 [inline]
 del_device_store+0x2d0/0x380 drivers/net/netdevsim/bus.c:354
 kernfs_fop_write_iter+0x379/0x4c0 fs/kernfs/file.c:296
 call_write_iter include/linux/fs.h:2173 [inline]
 new_sync_write fs/read_write.c:507 [inline]
 vfs_write+0x712/0xd00 fs/read_write.c:594
 ksys_write+0x14d/0x250 fs/read_write.c:647
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

Last potentially related work creation:
 kasan_save_stack+0x35/0x60 mm/kasan/common.c:38
 kasan_record_aux_stack+0xb8/0x100 mm/kasan/generic.c:348
 __call_rcu kernel/rcu/tree.c:3011 [inline]
 call_rcu+0x182/0x930 kernel/rcu/tree.c:3091
 qdisc_put net/sched/sch_generic.c:1047 [inline]
 shutdown_scheduler_queue net/sched/sch_generic.c:1100 [inline]
 netdev_for_each_tx_queue include/linux/netdevice.h:2388 [inline]
 dev_shutdown+0x19f/0x710 net/sched/sch_generic.c:1408
 unregister_netdevice_many+0xa0c/0x18f0 net/core/dev.c:11127
 unregister_netdevice_queue+0x31c/0x360 net/core/dev.c:11067
 unregister_netdevice include/linux/netdevice.h:3029 [inline]
 __tun_detach+0xd4a/0x1500 drivers/net/tun.c:686
 tun_detach drivers/net/tun.c:702 [inline]
 tun_chr_close+0x109/0x1b0 drivers/net/tun.c:3440
 __fput+0x234/0x930 fs/file_table.c:311
 task_work_run+0x125/0x1a0 kernel/task_work.c:188
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop+0x10f/0x130 kernel/entry/common.c:181
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214
 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
 syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

Second to last potentially related work creation:
 kasan_save_stack+0x35/0x60 mm/kasan/common.c:38
 kasan_record_aux_stack+0xb8/0x100 mm/kasan/generic.c:348
 __call_rcu kernel/rcu/tree.c:3011 [inline]
 call_rcu+0x182/0x930 kernel/rcu/tree.c:3091
 qdisc_put net/sched/sch_generic.c:1047 [inline]
 shutdown_scheduler_queue net/sched/sch_generic.c:1100 [inline]
 netdev_for_each_tx_queue include/linux/netdevice.h:2388 [inline]
 dev_shutdown+0x19f/0x710 net/sched/sch_generic.c:1408
 unregister_netdevice_many+0xa0c/0x18f0 net/core/dev.c:11127
 unregister_netdevice_queue+0x31c/0x360 net/core/dev.c:11067
 unregister_netdevice include/linux/netdevice.h:3029 [inline]
 __tun_detach+0xd4a/0x1500 drivers/net/tun.c:686
 tun_detach drivers/net/tun.c:702 [inline]
 tun_chr_close+0x109/0x1b0 drivers/net/tun.c:3440
 __fput+0x234/0x930 fs/file_table.c:311
 task_work_run+0x125/0x1a0 kernel/task_work.c:188
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop+0x10f/0x130 kernel/entry/common.c:181
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214
 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
 syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

The buggy address belongs to the object at ffff88807ad4b000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 352 bytes inside of
 2048-byte region [ffff88807ad4b000, ffff88807ad4b800)
The buggy address belongs to the page:
page:ffffea0001eb5200 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88807ad4f000 pfn:0x7ad48
head:ffffea0001eb5200 order:3 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 ffffea0001525008 ffffea00006ef008 ffff888016842000
raw: ffff88807ad4f000 0000000000080007 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0x1d2a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 5836, ts 134008795312, free_ts 132565097537
 prep_new_page mm/page_alloc.c:2426 [inline]
 get_page_from_freelist+0x1b77/0x1c60 mm/page_alloc.c:4192
 __alloc_pages+0x1e1/0x470 mm/page_alloc.c:5487
 alloc_slab_page mm/slub.c:1780 [inline]
 allocate_slab mm/slub.c:1917 [inline]
 new_slab+0xc0/0x4b0 mm/slub.c:1980
 ___slab_alloc+0x81e/0xdf0 mm/slub.c:3013
 __slab_alloc mm/slub.c:3100 [inline]
 slab_alloc_node mm/slub.c:3191 [inline]
 __kmalloc_node_track_caller+0x1fc/0x3a0 mm/slub.c:4963
 kmalloc_reserve net/core/skbuff.c:356 [inline]
 pskb_expand_head+0x127/0x10f0 net/core/skbuff.c:1709
 skb_expand_head+0x1a9/0x480 net/core/skbuff.c:1867
 ip6_finish_output2+0x1215/0x1500 net/ipv6/ip6_output.c:74
 ip6tunnel_xmit include/net/ip6_tunnel.h:160 [inline]
 udp_tunnel6_xmit_skb+0x539/0x9c0 net/ipv6/ip6_udp_tunnel.c:109
 send6+0x54c/0x840 drivers/net/wireguard/socket.c:152
 wg_socket_send_skb_to_peer+0x10d/0x1c0 drivers/net/wireguard/socket.c:178
 wg_packet_send_handshake_initiation drivers/net/wireguard/send.c:40 [inline]
 wg_packet_handshake_send_worker+0x1d8/0x310 drivers/net/wireguard/send.c:51
 process_one_work+0x863/0x1000 kernel/workqueue.c:2310
 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1340 [inline]
 free_pcp_prepare mm/page_alloc.c:1391 [inline]
 free_unref_page_prepare+0x637/0x6c0 mm/page_alloc.c:3317
 free_unref_page+0x94/0x280 mm/page_alloc.c:3396
 free_slab mm/slub.c:2020 [inline]
 discard_slab mm/slub.c:2026 [inline]
 __unfreeze_partials+0x1a5/0x200 mm/slub.c:2512
 put_cpu_partial+0x12d/0x190 mm/slub.c:2592
 qlist_free_all+0x35/0x90 mm/kasan/quarantine.c:176
 kasan_quarantine_reduce+0x150/0x160 mm/kasan/quarantine.c:283
 __kasan_slab_alloc+0x2f/0xd0 mm/kasan/common.c:444
 kasan_slab_alloc include/linux/kasan.h:254 [inline]
 slab_post_alloc_hook+0x4c/0x380 mm/slab.h:519
 slab_alloc_node mm/slub.c:3225 [inline]
 __kmalloc_node_track_caller+0x156/0x3a0 mm/slub.c:4963
 kmalloc_reserve net/core/skbuff.c:356 [inline]
 __alloc_skb+0x22c/0x750 net/core/skbuff.c:427
 alloc_skb include/linux/skbuff.h:1162 [inline]
 nlmsg_new include/net/netlink.h:953 [inline]
 inet_netconf_notify_devconf+0x16f/0x230 net/ipv4/devinet.c:2121
 __devinet_sysctl_unregister net/ipv4/devinet.c:2630 [inline]
 devinet_sysctl_unregister net/ipv4/devinet.c:2654 [inline]
 inetdev_destroy net/ipv4/devinet.c:326 [inline]
 inetdev_event+0x71c/0x1360 net/ipv4/devinet.c:1611
 notifier_call_chain kernel/notifier.c:83 [inline]
 raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:391
 call_netdevice_notifiers_extack net/core/dev.c:2061 [inline]
 call_netdevice_notifiers net/core/dev.c:2075 [inline]
 unregister_netdevice_many+0xf57/0x18f0 net/core/dev.c:11134
 unregister_netdevice_queue+0x31c/0x360 net/core/dev.c:11067
 unregister_netdevice include/linux/netdevice.h:3029 [inline]
 __tun_detach+0xd4a/0x1500 drivers/net/tun.c:686

Memory state around the buggy address:
 ffff88807ad4b000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88807ad4b080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88807ad4b100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                       ^
 ffff88807ad4b180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88807ad4b200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================