KASAN: use-after-free Read in vhci_urb

Kernel	Title	Rank 🛈	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
linux-5.15	KASAN: use-after-free Read in vhci_urb_enqueue (2)	19				1	74d	74d	0/3	upstream: reported on 2025/06/15 13:28
usb 42-1: device descriptor read/8, error -71
usb 42-1: SetAddress Request (3) to port 0
==================================================================
BUG: KASAN: use-after-free in kobject_put+0x2a0/0x460 lib/kobject.c:757
Read of size 1 at addr ffff8880770b00e4 by task kworker/0:7/5186

CPU: 0 PID: 5186 Comm: kworker/0:7 Not tainted 5.15.178-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Workqueue: usb_hub_wq hub_event
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106
 print_address_description+0x63/0x3b0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:434 [inline]
 kasan_report+0x16b/0x1c0 mm/kasan/report.c:451
 kobject_put+0x2a0/0x460 lib/kobject.c:757
 vhci_urb_enqueue+0x9bc/0xf30 drivers/usb/usbip/vhci_hcd.c:767
 usb_hcd_submit_urb+0x368/0x1de0 drivers/usb/core/hcd.c:1559
 usb_start_wait_urb+0x10f/0x510 drivers/usb/core/message.c:58
 usb_internal_control_msg drivers/usb/core/message.c:102 [inline]
 usb_control_msg+0x2ad/0x4c0 drivers/usb/core/message.c:153
 hub_set_address drivers/usb/core/hub.c:4659 [inline]
 hub_port_init+0xc1e/0x27d0 drivers/usb/core/hub.c:4971
 hub_port_connect drivers/usb/core/hub.c:5386 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5597 [inline]
 port_event drivers/usb/core/hub.c:5743 [inline]
 hub_event+0x28ed/0x54c0 drivers/usb/core/hub.c:5825
 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310
 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457
 kthread+0x3f6/0x4f0 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>

Allocated by task 5186:
 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+0xba/0xf0 mm/kasan/common.c:513
 kasan_kmalloc include/linux/kasan.h:264 [inline]
 kmem_cache_alloc_trace+0x143/0x290 mm/slub.c:3247
 kmalloc include/linux/slab.h:591 [inline]
 kzalloc include/linux/slab.h:721 [inline]
 usb_alloc_dev+0x5b/0xe50 drivers/usb/core/usb.c:704
 hub_port_connect drivers/usb/core/hub.c:5359 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5597 [inline]
 port_event drivers/usb/core/hub.c:5743 [inline]
 hub_event+0x2290/0x54c0 drivers/usb/core/hub.c:5825
 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310
 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457
 kthread+0x3f6/0x4f0 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287

Freed by task 154:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track+0x4b/0x80 mm/kasan/common.c:46
 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360
 ____kasan_slab_free+0xd8/0x120 mm/kasan/common.c:366
 kasan_slab_free include/linux/kasan.h:230 [inline]
 slab_free_hook mm/slub.c:1705 [inline]
 slab_free_freelist_hook+0xdd/0x160 mm/slub.c:1731
 slab_free mm/slub.c:3499 [inline]
 kfree+0xf1/0x270 mm/slub.c:4559
 device_release+0x91/0x1c0
 kobject_cleanup lib/kobject.c:713 [inline]
 kobject_release lib/kobject.c:744 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x224/0x460 lib/kobject.c:761
 vhci_device_reset+0x61/0x150 drivers/usb/usbip/vhci_hcd.c:1081
 event_handler+0x2ea/0x4b0 drivers/usb/usbip/usbip_event.c:85
 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310
 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457
 kthread+0x3f6/0x4f0 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287

The buggy address belongs to the object at ffff8880770b0000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 228 bytes inside of
 2048-byte region [ffff8880770b0000, ffff8880770b0800)
The buggy address belongs to the page:
page:ffffea0001dc2c00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x770b0
head:ffffea0001dc2c00 order:3 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 dead000000000100 dead000000000122 ffff888017442000
raw: 0000000000000000 0000000000080008 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 0xd28c0(GFP_NOWAIT|__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 4174, ts 48510871056, free_ts 48455791193
 prep_new_page mm/page_alloc.c:2426 [inline]
 get_page_from_freelist+0x3b78/0x3d40 mm/page_alloc.c:4192
 __alloc_pages+0x272/0x700 mm/page_alloc.c:5465
 alloc_slab_page mm/slub.c:1775 [inline]
 allocate_slab mm/slub.c:1912 [inline]
 new_slab+0xbb/0x4b0 mm/slub.c:1975
 ___slab_alloc+0x6f6/0xe10 mm/slub.c:3008
 __slab_alloc mm/slub.c:3095 [inline]
 slab_alloc_node mm/slub.c:3186 [inline]
 __kmalloc_node_track_caller+0x1f6/0x390 mm/slub.c:4958
 kmalloc_reserve net/core/skbuff.c:356 [inline]
 pskb_expand_head+0x111/0x1130 net/core/skbuff.c:1709
 netlink_trim+0x183/0x220 net/netlink/af_netlink.c:1293
 netlink_broadcast_filtered+0x62/0x11a0 net/netlink/af_netlink.c:1498
 netlink_broadcast net/netlink/af_netlink.c:1543 [inline]
 nlmsg_multicast include/net/netlink.h:1033 [inline]
 nlmsg_notify+0xf7/0x1b0 net/netlink/af_netlink.c:2532
 rtnl_notify net/core/rtnetlink.c:759 [inline]
 rtmsg_ifinfo_send net/core/rtnetlink.c:3905 [inline]
 rtmsg_ifinfo_event net/core/rtnetlink.c:3920 [inline]
 rtnetlink_event+0x155/0x1b0 net/core/rtnetlink.c:5698
 notifier_call_chain kernel/notifier.c:83 [inline]
 raw_notifier_call_chain+0xd0/0x170 kernel/notifier.c:391
 call_netdevice_notifiers_info net/core/dev.c:2018 [inline]
 call_netdevice_notifiers_extack net/core/dev.c:2030 [inline]
 call_netdevice_notifiers net/core/dev.c:2044 [inline]
 dev_set_mac_address+0x325/0x470 net/core/dev.c:9082
 dev_set_mac_address_user+0x2d/0x50 net/core/dev.c:9096
 do_setlink+0x7f0/0x3d80 net/core/rtnetlink.c:2731
 __rtnl_newlink net/core/rtnetlink.c:3447 [inline]
 rtnl_newlink+0x17d6/0x2070 net/core/rtnetlink.c:3569
 rtnetlink_rcv_msg+0x993/0xee0 net/core/rtnetlink.c:5647
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+0xc34/0xcf0 mm/page_alloc.c:3317
 free_unref_page+0x95/0x2d0 mm/page_alloc.c:3396
 free_slab mm/slub.c:2015 [inline]
 discard_slab mm/slub.c:2021 [inline]
 __unfreeze_partials+0x1b7/0x210 mm/slub.c:2507
 put_cpu_partial+0x132/0x1a0 mm/slub.c:2587
 do_slab_free mm/slub.c:3487 [inline]
 ___cache_free+0xe3/0x100 mm/slub.c:3506
 qlist_free_all+0x36/0x90 mm/kasan/quarantine.c:176
 kasan_quarantine_reduce+0x162/0x180 mm/kasan/quarantine.c:283
 __kasan_slab_alloc+0x2f/0xc0 mm/kasan/common.c:444
 kasan_slab_alloc include/linux/kasan.h:254 [inline]
 slab_post_alloc_hook+0x53/0x380 mm/slab.h:519
 slab_alloc_node mm/slub.c:3220 [inline]
 kmem_cache_alloc_node+0x121/0x2c0 mm/slub.c:3256
 __alloc_skb+0xdd/0x590 net/core/skbuff.c:415
 alloc_skb include/linux/skbuff.h:1162 [inline]
 alloc_skb_with_frags+0xa3/0x780 net/core/skbuff.c:6170
 sock_alloc_send_pskb+0x915/0xa50 net/core/sock.c:2533
 mld_newpack+0x1b4/0xa20 net/ipv6/mcast.c:1748
 add_grhead net/ipv6/mcast.c:1851 [inline]
 add_grec+0x1328/0x1770 net/ipv6/mcast.c:1989
 mld_send_cr net/ipv6/mcast.c:2115 [inline]
 mld_ifc_work+0x68f/0xc90 net/ipv6/mcast.c:2653

Memory state around the buggy address:
 ffff8880770aff80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880770b0000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880770b0080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                       ^
 ffff8880770b0100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880770b0180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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