Re: [syzbot] [usb?] KASAN: slab-use-after-free Read in vhci_cleanup_unlink_list

[Aleksandr Nogikh]

#syz invalid

See the discussion at
https://lore.kernel.org/all/6a88012e.dbb3a75c.13dd47.0007.GAE@xxxxxxxxxx/T/

On Thu, Aug 6, 2026 at 8:07 AM syzbot
<syzbot+f4518ac0a3dd3aafde38@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
>
> syzbot has found a reproducer for the following issue on:
>
> HEAD commit:    0d8395707651 Merge tag 'soc-fixes-7.2-2' of git://git.kern..
> git tree:       upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=1455929e580000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=145fa60d73086782
> dashboard link: https://syzkaller.appspot.com/bug?extid=f4518ac0a3dd3aafde38
> compiler:       gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=12e5bbb9580000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=16ffb7b9580000
>
> Downloadable assets:
> disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-0d839570.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/0b7275b6c889/vmlinux-0d839570.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/b752a676c1dd/bzImage-0d839570.xz
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+f4518ac0a3dd3aafde38@xxxxxxxxxxxxxxxxxxxxxxxxx
>
> vhci_hcd vhci_hcd.0: release socket
> ==================================================================
> BUG: KASAN: slab-use-after-free in vdev_to_vhci_hcd drivers/usb/usbip/vhci.h:171 [inline]
> BUG: KASAN: slab-use-after-free in vhci_cleanup_unlink_list+0x44/0x456 drivers/usb/usbip/vhci_hcd.c:985
> Read of size 4 at addr ffff88802bf5d230 by task kworker/u32:3/5807
>
> CPU: 1 UID: 0 PID: 5807 Comm: kworker/u32:3 Not tainted syzkaller #0 PREEMPT(full)
> Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
> Workqueue: usbip_event event_handler
> Call Trace:
>  <TASK>
>  __dump_stack lib/dump_stack.c:94 [inline]
>  dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
>  print_address_description mm/kasan/report.c:378 [inline]
>  print_report+0x13d/0x4b0 mm/kasan/report.c:482
>  kasan_report+0xdf/0x1c0 mm/kasan/report.c:595
>  vdev_to_vhci_hcd drivers/usb/usbip/vhci.h:171 [inline]
>  vhci_cleanup_unlink_list+0x44/0x456 drivers/usb/usbip/vhci_hcd.c:985
>  vhci_device_unlink_cleanup drivers/usb/usbip/vhci_hcd.c:1028 [inline]
>  vhci_shutdown_connection.cold+0x165/0x37c drivers/usb/usbip/vhci_hcd.c:1069
>  event_handler+0x216/0x570 drivers/usb/usbip/usbip_event.c:79
>  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
>  </TASK>
>
> Allocated by task 1:
>  kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
>  kasan_save_track+0x14/0x30 mm/kasan/common.c:78
>  poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
>  __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415
>  kasan_kmalloc include/linux/kasan.h:263 [inline]
>  __do_kmalloc_node mm/slub.c:5334 [inline]
>  __kmalloc_noprof+0x322/0x820 mm/slub.c:5359
>  _kmalloc_noprof include/linux/slab.h:992 [inline]
>  _kzalloc_noprof include/linux/slab.h:1309 [inline]
>  __usb_create_hcd+0x5e/0xac0 drivers/usb/core/hcd.c:2566
>  vhci_hcd_probe+0x1a5/0x4e0 drivers/usb/usbip/vhci_hcd.c:1394
>  platform_probe+0x106/0x1d0 drivers/base/platform.c:1439
>  call_driver_probe drivers/base/dd.c:628 [inline]
>  really_probe+0x241/0xa60 drivers/base/dd.c:706
>  __driver_probe_device+0x20e/0x450 drivers/base/dd.c:868
>  driver_probe_device+0x4a/0x140 drivers/base/dd.c:898
>  __device_attach_driver+0x1df/0x320 drivers/base/dd.c:1026
>  bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500
>  __device_attach+0x1e4/0x4d0 drivers/base/dd.c:1098
>  device_initial_probe+0xaf/0xd0 drivers/base/dd.c:1153
>  bus_probe_device+0x64/0x160 drivers/base/bus.c:620
>  device_add+0x121d/0x1970 drivers/base/core.c:3772
>  platform_device_add+0x35a/0x800 drivers/base/platform.c:762
>  platform_device_register_full+0x5cf/0x830 drivers/base/platform.c:902
>  vhci_hcd_init+0x1a1/0x2f0 drivers/usb/usbip/vhci_hcd.c:1557
>  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
>
> Freed by task 5926:
>  kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
>  kasan_save_track+0x14/0x30 mm/kasan/common.c:78
>  kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
>  poison_slab_object mm/kasan/common.c:253 [inline]
>  __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285
>  kasan_slab_free include/linux/kasan.h:235 [inline]
>  slab_free_hook mm/slub.c:2677 [inline]
>  slab_free mm/slub.c:6377 [inline]
>  kfree+0x22b/0x6c0 mm/slub.c:6692
>  hcd_release drivers/usb/core/hcd.c:2690 [inline]
>  kref_put include/linux/kref.h:65 [inline]
>  usb_put_hcd drivers/usb/core/hcd.c:2704 [inline]
>  usb_put_hcd+0x149/0x1f0 drivers/usb/core/hcd.c:2701
>  vhci_hcd_remove+0xb5/0x1b0 drivers/usb/usbip/vhci_hcd.c:1431
>  platform_remove+0x5f/0x80 drivers/base/platform.c:1456
>  device_remove+0xcb/0x180 drivers/base/dd.c:616
>  __device_release_driver drivers/base/dd.c:1349 [inline]
>  device_release_driver_internal+0x44e/0x620 drivers/base/dd.c:1372
>  unbind_store+0xf8/0x110 drivers/base/bus.c:244
>  drv_attr_store+0x74/0xb0 drivers/base/bus.c:125
>  sysfs_kf_write+0xf2/0x150 fs/sysfs/file.c:145
>  kernfs_fop_write_iter+0x3e0/0x5f0 fs/kernfs/file.c:345
>  new_sync_write fs/read_write.c:595 [inline]
>  vfs_write+0x6ac/0x1050 fs/read_write.c:687
>  ksys_write+0x12a/0x250 fs/read_write.c:739
>  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
>
> Last potentially related work creation:
>  kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
>  kasan_record_aux_stack+0xa7/0xc0 mm/kasan/generic.c:556
>  insert_work+0x36/0x230 kernel/workqueue.c:2226
>  __queue_work+0x9bc/0x12b0 kernel/workqueue.c:2401
>  queue_work_on+0x1a9/0x1e0 kernel/workqueue.c:2452
>  queue_work include/linux/workqueue.h:699 [inline]
>  usb_hcd_giveback_urb+0x330/0x4a0 drivers/usb/core/hcd.c:1758
>  usb_rh_urb_dequeue drivers/usb/core/hcd.c:845 [inline]
>  unlink1+0x418/0x510 drivers/usb/core/hcd.c:1580
>  usb_hcd_unlink_urb+0x131/0x210 drivers/usb/core/hcd.c:1617
>  usb_kill_urb drivers/usb/core/urb.c:716 [inline]
>  usb_kill_urb+0x121/0x320 drivers/usb/core/urb.c:703
>  hub_quiesce+0x1e9/0x320 drivers/usb/core/hub.c:1412
>  hub_suspend+0x4ab/0x9e0 drivers/usb/core/hub.c:4008
>  usb_suspend_interface drivers/usb/core/driver.c:1323 [inline]
>  usb_suspend_both+0x288/0x950 drivers/usb/core/driver.c:1446
>  usb_runtime_suspend+0x49/0x120 drivers/usb/core/driver.c:2000
>  __rpm_callback+0xc8/0x620 drivers/base/power/runtime.c:406
>  rpm_callback+0x16a/0x1b0 drivers/base/power/runtime.c:460
>  rpm_suspend+0x2f4/0x11a0 drivers/base/power/runtime.c:698
>  __pm_runtime_suspend+0xba/0x1a0 drivers/base/power/runtime.c:1167
>  pm_runtime_autosuspend include/linux/pm_runtime.h:415 [inline]
>  usb_runtime_idle+0x7e/0x90 drivers/usb/core/driver.c:2037
>  rpm_idle+0x322/0x790 drivers/base/power/runtime.c:550
>  pm_runtime_work+0x120/0x150 drivers/base/power/runtime.c:995
>  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
>
> Second to last potentially related work creation:
>  kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
>  kasan_record_aux_stack+0xa7/0xc0 mm/kasan/generic.c:556
>  insert_work+0x36/0x230 kernel/workqueue.c:2226
>  __queue_work+0x9bc/0x12b0 kernel/workqueue.c:2401
>  queue_work_on+0x1a9/0x1e0 kernel/workqueue.c:2452
>  queue_work include/linux/workqueue.h:699 [inline]
>  usb_hcd_giveback_urb+0x3b8/0x4a0 drivers/usb/core/hcd.c:1760
>  rh_call_control drivers/usb/core/hcd.c:706 [inline]
>  rh_urb_enqueue drivers/usb/core/hcd.c:817 [inline]
>  usb_hcd_submit_urb+0xab7/0x2150 drivers/usb/core/hcd.c:1538
>  usb_submit_urb+0x827/0x19b0 drivers/usb/core/urb.c:586
>  usb_start_wait_urb+0x10e/0x580 drivers/usb/core/message.c:62
>  usb_internal_control_msg drivers/usb/core/message.c:117 [inline]
>  usb_control_msg+0x328/0x4b0 drivers/usb/core/message.c:167
>  set_port_feature drivers/usb/core/hub.c:466 [inline]
>  hub_suspend+0x826/0x9e0 drivers/usb/core/hub.c:3996
>  usb_suspend_interface drivers/usb/core/driver.c:1323 [inline]
>  usb_suspend_both+0x288/0x950 drivers/usb/core/driver.c:1446
>  usb_runtime_suspend+0x49/0x120 drivers/usb/core/driver.c:2000
>  __rpm_callback+0xc8/0x620 drivers/base/power/runtime.c:406
>  rpm_callback+0x16a/0x1b0 drivers/base/power/runtime.c:460
>  rpm_suspend+0x2f4/0x11a0 drivers/base/power/runtime.c:698
>  __pm_runtime_suspend+0xba/0x1a0 drivers/base/power/runtime.c:1167
>  pm_runtime_autosuspend include/linux/pm_runtime.h:415 [inline]
>  usb_runtime_idle+0x7e/0x90 drivers/usb/core/driver.c:2037
>  rpm_idle+0x322/0x790 drivers/base/power/runtime.c:550
>  pm_runtime_work+0x120/0x150 drivers/base/power/runtime.c:995
>  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
>
> The buggy address belongs to the object at ffff88802bf5c000
>  which belongs to the cache kmalloc-8k of size 8192
> The buggy address is located 4656 bytes inside of
>  freed 8192-byte region [ffff88802bf5c000, ffff88802bf5e000)
>
> The buggy address belongs to the physical page:
> page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2bf58
> head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
> flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
> page_type: f5(slab)
> raw: 00fff00000000040 ffff88801bc43180 dead000000000122 0000000000000000
> raw: 0000000000000000 0000000800020002 00000000f5000000 0000000000000000
> head: 00fff00000000040 ffff88801bc43180 dead000000000122 0000000000000000
> head: 0000000000000000 0000000800020002 00000000f5000000 0000000000000000
> head: 00fff00000000003 fffffffffffffe01 00000000ffffffff 00000000ffffffff
> head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008
> page dumped because: kasan: bad access detected
> page_owner tracks the page as allocated
> page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, tgid 1 (swapper/0), ts 7941256619, free_ts 7717626992
>  set_page_owner include/linux/page_owner.h:32 [inline]
>  post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1859
>  prep_new_page mm/page_alloc.c:1867 [inline]
>  get_page_from_freelist+0xf48/0x3530 mm/page_alloc.c:3946
>  __alloc_frozen_pages_noprof+0x299/0x2dc0 mm/page_alloc.c:5304
>  alloc_slab_page mm/slub.c:3266 [inline]
>  allocate_slab mm/slub.c:3380 [inline]
>  new_slab+0xa2/0x640 mm/slub.c:3426
>  refill_objects+0xe3/0x410 mm/slub.c:7310
>  refill_sheaf mm/slub.c:2804 [inline]
>  __pcs_replace_empty_main+0x376/0x680 mm/slub.c:4675
>  alloc_from_pcs mm/slub.c:4773 [inline]
>  slab_alloc_node mm/slub.c:4905 [inline]
>  __do_kmalloc_node mm/slub.c:5333 [inline]
>  __kmalloc_noprof+0x66d/0x820 mm/slub.c:5359
>  _kmalloc_noprof include/linux/slab.h:992 [inline]
>  acpi_ut_initialize_buffer+0x144/0x220 drivers/acpi/acpica/utalloc.c:327
>  acpi_rs_create_pci_routing_table+0x135/0xe00 drivers/acpi/acpica/rscreate.c:212
>  acpi_rs_get_prt_method_data+0xc1/0x150 drivers/acpi/acpica/rsutils.c:456
>  acpi_get_irq_routing_table+0xb8/0x140 drivers/acpi/acpica/rsxface.c:137
>  acpi_pci_irq_find_prt_entry+0x179/0xdd0 drivers/acpi/pci_irq.c:215
>  acpi_pci_irq_lookup+0x8e/0x6b0 drivers/acpi/pci_irq.c:299
>  acpi_pci_irq_enable+0x1f5/0x6f0 drivers/acpi/pci_irq.c:414
>  pcibios_enable_device+0xb6/0xe0 arch/x86/pci/common.c:699
>  do_pci_enable_device+0x21f/0x4a0 drivers/pci/pci.c:1998
> page last free pid 1351 tgid 1351 stack trace:
>  reset_page_owner include/linux/page_owner.h:25 [inline]
>  __free_pages_prepare mm/page_alloc.c:1406 [inline]
>  free_pages_prepare+0x586/0xd80 mm/page_alloc.c:1451
>  __free_contig_range_common+0x14f/0x250 mm/page_alloc.c:6897
>  __free_contig_range mm/page_alloc.c:6942 [inline]
>  free_pages_bulk+0x12a/0x200 mm/page_alloc.c:5257
>  vm_area_free_pages+0xad/0x2b0 mm/vmalloc.c:3439
>  vfree mm/vmalloc.c:3488 [inline]
>  vfree+0x107/0x750 mm/vmalloc.c:3462
>  delayed_vfree_work+0x56/0x80 mm/vmalloc.c:3392
>  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
>
> Memory state around the buggy address:
>  ffff88802bf5d100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>  ffff88802bf5d180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> >ffff88802bf5d200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>                                      ^
>  ffff88802bf5d280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>  ffff88802bf5d300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ==================================================================
>
>
> ---
> If you want syzbot to run the reproducer, reply with:
> #syz test: git://repo/address.git branch-or-commit-hash
> If you attach or paste a git patch, syzbot will apply it before testing.