KASAN: use-after-free Read in roccat_disconnect

Status: upstream: reported C repro on 2026/11/01 22:08
Reported-by: syzbot+857525b5dddc0bc4d0e1@syzkaller.appspotmail.com
First crash: 6d04h, last: 2d06h
▶ ▼ Similar bugs (7)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-5-10 KASAN: use-after-free Read in roccat_disconnect 19 syz, C 10 5d14h 50d 0/2 upstream: reported C repro on 2026/09/18 05:49
android-5-15 KASAN: use-after-free Read in roccat_disconnect 19 syz, C 12 4d05h 57d 0/2 upstream: reported C repro on 2026/09/11 19:13
android-6-1 KASAN: use-after-free Read in roccat_disconnect 19 syz, C 14 4d05h 16d 0/2 upstream: reported C repro on 2026/10/22 14:43
linux-5.15 KASAN: use-after-free Read in roccat_disconnect 19 syz, C 9 19h56m 12d 0/3 upstream: reported C repro on 2026/10/26 05:36
linux-6.6 KASAN: slab-use-after-free Read in roccat_disconnect 19 syz, C 9 6d11h 16d 0/2 upstream: reported C repro on 2026/10/22 21:24
android-6-12 KASAN: slab-use-after-free Read in roccat_disconnect origin:lts 19 syz, C 39 3d05h 55d 0/1 premoderation: reported C repro on 2026/09/13 11:34
upstream KASAN: slab-use-after-free Read in roccat_disconnect prio:high input usb 19 syz, C error error 20 46d 66d 2/29 upstream: reported C repro on 2026/09/02 18:57

Sample crash report:
usb 1-1: USB disconnect, device number 2
==================================================================
BUG: KASAN: use-after-free in roccat_disconnect+0x236/0x240 drivers/hid/hid-roccat.c:382
Read of size 4 at addr ffff888145369808 by task kworker/1:1/26

CPU: 1 PID: 26 Comm: kworker/1:1 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026
Workqueue: usb_hub_wq hub_event
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:316 [inline]
 print_report+0xa8/0x210 mm/kasan/report.c:420
 kasan_report+0x10b/0x140 mm/kasan/report.c:524
 roccat_disconnect+0x236/0x240 drivers/hid/hid-roccat.c:382
 savu_remove_specials drivers/hid/hid-roccat-savu.c:107 [inline]
 savu_remove+0xe5/0x160 drivers/hid/hid-roccat-savu.c:147
 hid_device_remove+0xba/0x1b0 drivers/hid/hid-core.c:2762
 device_remove drivers/base/dd.c:547 [inline]
 __device_release_driver drivers/base/dd.c:1279 [inline]
 device_release_driver_internal+0x47d/0x7c0 drivers/base/dd.c:1305
 bus_remove_device+0x2dd/0x400 drivers/base/bus.c:531
 device_del+0x63f/0xa80 drivers/base/core.c:3901
 hid_remove_device drivers/hid/hid-core.c:2938 [inline]
 hid_destroy_device+0x66/0x100 drivers/hid/hid-core.c:2957
 usbhid_disconnect+0x9b/0xc0 drivers/hid/usbhid/hid-core.c:1470
 usb_unbind_interface+0x200/0x870 drivers/usb/core/driver.c:457
 device_remove drivers/base/dd.c:549 [inline]
 __device_release_driver drivers/base/dd.c:1279 [inline]
 device_release_driver_internal+0x4cf/0x7c0 drivers/base/dd.c:1305
 bus_remove_device+0x2dd/0x400 drivers/base/bus.c:531
 device_del+0x63f/0xa80 drivers/base/core.c:3901
 usb_disable_device+0x3e7/0x8a0 drivers/usb/core/message.c:1478
 usb_disconnect+0x33c/0x8a0 drivers/usb/core/hub.c:2324
 hub_port_connect drivers/usb/core/hub.c:5371 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5667 [inline]
 port_event drivers/usb/core/hub.c:5827 [inline]
 hub_event+0x1d27/0x5200 drivers/usb/core/hub.c:5909
 process_one_work+0x8ab/0x1160 kernel/workqueue.c:2292
 worker_thread+0xaf5/0x12a0 kernel/workqueue.c:2439
 kthread+0x29d/0x330 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>

Allocated by task 4323:
 kasan_save_stack mm/kasan/common.c:46 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:53
 ____kasan_kmalloc mm/kasan/common.c:375 [inline]
 __kasan_kmalloc+0x8e/0xa0 mm/kasan/common.c:384
 kmalloc include/linux/slab.h:563 [inline]
 kzalloc include/linux/slab.h:699 [inline]
 roccat_connect+0x59/0x490 drivers/hid/hid-roccat.c:315
 savu_init_specials drivers/hid/hid-roccat-savu.c:81 [inline]
 savu_probe+0x1af/0x350 drivers/hid/hid-roccat-savu.c:131
 __hid_device_probe drivers/hid/hid-core.c:2704 [inline]
 hid_device_probe+0x2b8/0x520 drivers/hid/hid-core.c:2743
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x24a/0xb40 drivers/base/dd.c:638
 __driver_probe_device+0x1f5/0x390 drivers/base/dd.c:804
 driver_probe_device+0x4f/0x420 drivers/base/dd.c:834
 __device_attach_driver+0x2c6/0x510 drivers/base/dd.c:962
 bus_for_each_drv+0x184/0x210 drivers/base/bus.c:429
 __device_attach+0x2a7/0x480 drivers/base/dd.c:1034
 bus_probe_device+0xba/0x1d0 drivers/base/bus.c:489
 device_add+0xbcf/0x1050 drivers/base/core.c:3713
 hid_add_device+0x361/0x500 drivers/hid/hid-core.c:2889
 usbhid_probe+0xc3f/0x1010 drivers/hid/usbhid/hid-core.c:1443
 usb_probe_interface+0x6e7/0xcf0 drivers/usb/core/driver.c:395
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x24a/0xb40 drivers/base/dd.c:638
 __driver_probe_device+0x1f5/0x390 drivers/base/dd.c:804
 driver_probe_device+0x4f/0x420 drivers/base/dd.c:834
 __device_attach_driver+0x2c6/0x510 drivers/base/dd.c:962
 bus_for_each_drv+0x184/0x210 drivers/base/bus.c:429
 __device_attach+0x2a7/0x480 drivers/base/dd.c:1034
 bus_probe_device+0xba/0x1d0 drivers/base/bus.c:489
 device_add+0xbcf/0x1050 drivers/base/core.c:3713
 usb_set_configuration+0x1ad8/0x2140 drivers/usb/core/message.c:2229
 usb_generic_driver_probe+0x89/0x150 drivers/usb/core/generic.c:238
 usb_probe_device+0x126/0x250 drivers/usb/core/driver.c:291
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x24a/0xb40 drivers/base/dd.c:638
 __driver_probe_device+0x1f5/0x390 drivers/base/dd.c:804
 driver_probe_device+0x4f/0x420 drivers/base/dd.c:834
 __device_attach_driver+0x2c6/0x510 drivers/base/dd.c:962
 bus_for_each_drv+0x184/0x210 drivers/base/bus.c:429
 __device_attach+0x2a7/0x480 drivers/base/dd.c:1034
 bus_probe_device+0xba/0x1d0 drivers/base/bus.c:489
 device_add+0xbcf/0x1050 drivers/base/core.c:3713
 usb_new_device+0xa01/0x15e0 drivers/usb/core/hub.c:2669
 hub_port_connect drivers/usb/core/hub.c:5527 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5667 [inline]
 port_event drivers/usb/core/hub.c:5827 [inline]
 hub_event+0x2b2f/0x5200 drivers/usb/core/hub.c:5909
 process_one_work+0x8ab/0x1160 kernel/workqueue.c:2292
 worker_thread+0xaf5/0x12a0 kernel/workqueue.c:2439
 kthread+0x29d/0x330 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

Freed by task 4463:
 kasan_save_stack mm/kasan/common.c:46 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:53
 kasan_save_free_info+0x27/0x40 mm/kasan/generic.c:516
 ____kasan_slab_free+0x126/0x1f0 mm/kasan/common.c:237
 kasan_slab_free include/linux/kasan.h:177 [inline]
 slab_free_hook mm/slub.c:1735 [inline]
 slab_free_freelist_hook+0x133/0x1b0 mm/slub.c:1761
 slab_free mm/slub.c:3694 [inline]
 __kmem_cache_free+0xb6/0x200 mm/slub.c:3707
 roccat_release+0x2a6/0x370 drivers/hid/hid-roccat.c:238
 __fput+0x20a/0x8b0 fs/file_table.c:320
 task_work_run+0x1d0/0x260 kernel/task_work.c:203
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:180
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:213
 __syscall_exit_to_user_mode_work kernel/entry/common.c:295 [inline]
 syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:306
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

The buggy address belongs to the object at ffff888145369800
 which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 8 bytes inside of
 1024-byte region [ffff888145369800, ffff888145369c00)

The buggy address belongs to the physical page:
page:ffffea000514da00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x145368
head:ffffea000514da00 order:3 compound_mapcount:0 compound_pincount:0
flags: 0x57ff00000010200(slab|head|node=1|zone=2|lastcpupid=0x7ff)
raw: 057ff00000010200 0000000000000000 dead000000000001 ffff888018441dc0
raw: 0000000000000000 0000000000100010 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, tgid 1 (swapper/0), ts 6709586395, free_ts 0
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x173/0x1a0 mm/page_alloc.c:2560
 prep_new_page mm/page_alloc.c:2567 [inline]
 get_page_from_freelist+0x206b/0x2180 mm/page_alloc.c:4358
 __alloc_pages+0x1ec/0x4f0 mm/page_alloc.c:5658
 alloc_page_interleave+0x24/0x1e0 mm/mempolicy.c:2117
 alloc_slab_page+0x5d/0x180 mm/slub.c:1805
 allocate_slab mm/slub.c:1950 [inline]
 new_slab+0x87/0x2d0 mm/slub.c:2003
 ___slab_alloc+0xbc5/0x1240 mm/slub.c:3161
 __slab_alloc mm/slub.c:3247 [inline]
 slab_alloc_node mm/slub.c:3332 [inline]
 __kmem_cache_alloc_node+0x126/0x270 mm/slub.c:3405
 __do_kmalloc_node mm/slab_common.c:935 [inline]
 __kmalloc+0xa3/0x240 mm/slab_common.c:949
 kmalloc_array include/linux/slab.h:615 [inline]
 vp_request_msix_vectors drivers/virtio/virtio_pci_common.c:115 [inline]
 vp_find_vqs_msix+0x352/0x1030 drivers/virtio/virtio_pci_common.c:311
 vp_find_vqs+0x4a/0x4b0 drivers/virtio/virtio_pci_common.c:409
 virtio_find_vqs include/linux/virtio_config.h:227 [inline]
 virtscsi_init+0x4e1/0x8d0 drivers/scsi/virtio_scsi.c:817
 virtscsi_probe+0x35b/0xcc0 drivers/scsi/virtio_scsi.c:874
 virtio_dev_probe+0x8b4/0xae0 drivers/virtio/virtio.c:305
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x24a/0xb40 drivers/base/dd.c:638
 __driver_probe_device+0x1f5/0x390 drivers/base/dd.c:804
page_owner free stack trace missing

Memory state around the buggy address:
 ffff888145369700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888145369780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888145369800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                      ^
 ffff888145369880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888145369900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Crashes (9):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/11/05 19:20 linux-6.1.y 08889840163e 2ee8459f .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan KASAN: use-after-free Read in roccat_disconnect
2026/11/05 17:53 linux-6.1.y 08889840163e 2ee8459f .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan KASAN: use-after-free Read in roccat_disconnect
2026/11/02 01:10 linux-6.1.y 08889840163e 25a0ae84 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan KASAN: use-after-free Read in roccat_disconnect
2026/11/02 17:43 linux-6.1.y 08889840163e 6969b601 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan KASAN: use-after-free Read in roccat_disconnect
2026/11/02 17:43 linux-6.1.y 08889840163e 6969b601 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan KASAN: use-after-free Read in roccat_disconnect
2026/11/01 23:19 linux-6.1.y 08889840163e 25a0ae84 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan KASAN: use-after-free Read in roccat_disconnect
2026/11/01 22:17 linux-6.1.y 08889840163e 25a0ae84 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan KASAN: use-after-free Read in roccat_disconnect
2026/11/01 22:15 linux-6.1.y 08889840163e 25a0ae84 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan KASAN: use-after-free Read in roccat_disconnect
2026/11/01 22:07 linux-6.1.y 08889840163e 25a0ae84 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan KASAN: use-after-free Read in roccat_disconnect
* Struck through repros no longer work on HEAD.