KASAN: slab-use-after-free Read in roccat_disconnect

Status: upstream: reported C repro on 2026/09/02 18:57
Subsystems: input usb
Labels: prio:high
[Documentation on labels]
Reported-by: syzbot+c492a9e154f81127551f@syzkaller.appspotmail.com
First crash: 48d, last: 26d
Cause bisection: failed (error log, bisect log)
  
▶ ▼ ✨ AI Patch Versions (1)
Version Stage Reported Report Link Job
1 moderation 2026/09/02 21:21 Discussion 01ccbae5-1a81-4a52-8c81-46a50f2410b6
▶ ▼ ✨ AI Jobs (2)
ID Workflow Result Correct Bug Created Started Finished Revision
01ccbae5 patching ❓ KASAN: slab-use-after-free Read in roccat_disconnect 2026/09/02 20:16 2026/09/02 20:16 2026/09/02 21:21 9941e97d
f5f1bd85 assessment-security DenialOfService: ✅ Exploitable: ✅ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ✅ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ ❓ KASAN: slab-use-after-free Read in roccat_disconnect 2026/09/02 01:38 2026/09/02 01:38 2026/09/02 02:06 587f6b29
▶ ▼ Discussions (2)
Title Replies (including bot) Last reply
[PATCH] HID: roccat: fix use-after-free and uninitialized-mutex races 3 (3) 2026/10/18 10:55
[syzbot] [input?] [usb?] KASAN: slab-use-after-free Read in roccat_disconnect 0 (6) 2026/10/16 11:06
▶ ▼ Similar bugs (4)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-6-12 KASAN: slab-use-after-free Read in roccat_disconnect 19 syz, C 21 20d 35d 0/1 premoderation: reported C repro on 2026/09/13 11:34
android-5-10 KASAN: use-after-free Read in roccat_disconnect 19 syz, C 4 15d 30d 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 6 8d11h 37d 0/2 upstream: reported C repro on 2026/09/11 19:13
android-6-1 KASAN: use-after-free Read in roccat_disconnect 19 2 26d 26d 0/2 premoderation: reported on 2026/09/22 18:49
▶ ▼ Last patch testing requests (8)
Created Duration User Patch Repo Result
2026/10/16 11:06 21m dmantipov@yandex.ru patch https://git.kernel.org/pub/scm/linux/kernel/git/hid/hid.git for-7.4/roccat OK job log log
2026/10/16 10:42 22m dmantipov@yandex.ru patch https://git.kernel.org/pub/scm/linux/kernel/git/hid/hid.git for-7.4/roccat report job log log
2026/10/08 22:50 3h39m retest repro upstream no crash job log log
2026/10/08 22:50 6h55m retest repro upstream no crash job log log
2026/10/06 23:10 15m retest repro upstream error job log
2026/09/29 06:32 47m dmantipov@yandex.ru patch https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 72d3fcf802c45d00b300f25b848a93c3a2bd7c7e OK job log log
2026/09/02 23:48 1h32m kartikey406@gmail.com patch upstream OK job log log
2026/09/02 23:07 21m kartikey406@gmail.com patch upstream report job log log
▶ ▼ Cause bisection attempts (4)
Created Duration User Patch Repo Result
2026/09/29 04:02 15h16m bisect upstream error job log
2026/09/20 16:36 0m bisect upstream error
2026/09/10 06:13 0m bisect upstream error
2026/09/02 03:13 0m bisect upstream error

Sample crash report:
usb 5-1: USB disconnect, device number 8
==================================================================
BUG: KASAN: slab-use-after-free in roccat_disconnect+0x23d/0x250 drivers/hid/hid-roccat.c:382
Read of size 4 at addr ffff8880316d8808 by task kworker/0:10/5734

CPU: 0 UID: 0 PID: 5734 Comm: kworker/0:10 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: usb_hub_wq hub_event
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_address_description+0x55/0x1e0 mm/kasan/report.c:378
 print_report+0x58/0x70 mm/kasan/report.c:482
 kasan_report+0x117/0x150 mm/kasan/report.c:595
 roccat_disconnect+0x23d/0x250 drivers/hid/hid-roccat.c:382
 savu_remove_specials drivers/hid/hid-roccat-savu.c:110 [inline]
 savu_remove+0xe9/0x160 drivers/hid/hid-roccat-savu.c:150
 hid_device_remove+0xc5/0x1c0 drivers/hid/hid-core.c:2897
 device_remove drivers/base/dd.c:616 [inline]
 __device_release_driver drivers/base/dd.c:1349 [inline]
 device_release_driver_internal+0x48b/0x880 drivers/base/dd.c:1372
 bus_remove_device+0x444/0x560 drivers/base/bus.c:664
 device_del+0x524/0x8f0 drivers/base/core.c:3965
 hid_remove_device drivers/hid/hid-core.c:3126 [inline]
 hid_destroy_device+0x6b/0x1b0 drivers/hid/hid-core.c:3148
 usbhid_disconnect+0x9f/0xc0 drivers/hid/usbhid/hid-core.c:1479
 usb_unbind_interface+0x295/0x9f0 drivers/usb/core/driver.c:461
 device_remove drivers/base/dd.c:618 [inline]
 __device_release_driver drivers/base/dd.c:1349 [inline]
 device_release_driver_internal+0x4f5/0x880 drivers/base/dd.c:1372
 bus_remove_device+0x444/0x560 drivers/base/bus.c:664
 device_del+0x524/0x8f0 drivers/base/core.c:3965
 usb_disable_device+0x3d4/0x8d0 drivers/usb/core/message.c:1478
 usb_disconnect+0x346/0x9a0 drivers/usb/core/hub.c:2350
 hub_port_connect drivers/usb/core/hub.c:5420 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5720 [inline]
 port_event drivers/usb/core/hub.c:5884 [inline]
 hub_event+0x1bbb/0x4d30 drivers/usb/core/hub.c:5966
 process_one_work kernel/workqueue.c:3396 [inline]
 process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3479
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3560
 kthread+0x38b/0x480 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Allocated by task 5414:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __kmalloc_cache_noprof+0x321/0x600 mm/slub.c:5563
 _kmalloc_noprof include/linux/slab.h:991 [inline]
 _kzalloc_noprof include/linux/slab.h:1312 [inline]
 roccat_connect+0x5d/0x4a0 drivers/hid/hid-roccat.c:315
 savu_init_specials drivers/hid/hid-roccat-savu.c:84 [inline]
 savu_probe+0x18e/0x340 drivers/hid/hid-roccat-savu.c:134
 __hid_device_probe drivers/hid/hid-core.c:2839 [inline]
 hid_device_probe+0x46a/0x870 drivers/hid/hid-core.c:2878
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x254/0xae0 drivers/base/dd.c:706
 __driver_probe_device+0x1e8/0x360 drivers/base/dd.c:868
 driver_probe_device+0x4f/0x240 drivers/base/dd.c:898
 __device_attach_driver+0x270/0x410 drivers/base/dd.c:1026
 bus_for_each_drv+0x258/0x2f0 drivers/base/bus.c:500
 __device_attach+0x2c4/0x450 drivers/base/dd.c:1098
 device_initial_probe+0xa1/0xd0 drivers/base/dd.c:1153
 bus_probe_device+0x12a/0x220 drivers/base/bus.c:620
 device_add+0x7d7/0xb80 drivers/base/core.c:3776
 hid_add_device+0x272/0x3e0 drivers/hid/hid-core.c:3065
 usbhid_probe+0x9d4/0xde0 drivers/hid/usbhid/hid-core.c:1452
 usb_probe_interface+0x788/0xe50 drivers/usb/core/driver.c:399
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x254/0xae0 drivers/base/dd.c:706
 __driver_probe_device+0x1e8/0x360 drivers/base/dd.c:868
 driver_probe_device+0x4f/0x240 drivers/base/dd.c:898
 __device_attach_driver+0x270/0x410 drivers/base/dd.c:1026
 bus_for_each_drv+0x258/0x2f0 drivers/base/bus.c:500
 __device_attach+0x2c4/0x450 drivers/base/dd.c:1098
 device_initial_probe+0xa1/0xd0 drivers/base/dd.c:1153
 bus_probe_device+0x12a/0x220 drivers/base/bus.c:620
 device_add+0x7d7/0xb80 drivers/base/core.c:3776
 usb_set_configuration+0x1ad8/0x2180 drivers/usb/core/message.c:2268
 usb_generic_driver_probe+0x8d/0x150 drivers/usb/core/generic.c:250
 usb_probe_device+0x1c3/0x3b0 drivers/usb/core/driver.c:293
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x254/0xae0 drivers/base/dd.c:706
 __driver_probe_device+0x1e8/0x360 drivers/base/dd.c:868
 driver_probe_device+0x4f/0x240 drivers/base/dd.c:898
 __device_attach_driver+0x270/0x410 drivers/base/dd.c:1026
 bus_for_each_drv+0x258/0x2f0 drivers/base/bus.c:500
 __device_attach+0x2c4/0x450 drivers/base/dd.c:1098
 device_initial_probe+0xa1/0xd0 drivers/base/dd.c:1153
 bus_probe_device+0x12a/0x220 drivers/base/bus.c:620
 device_add+0x7d7/0xb80 drivers/base/core.c:3776
 usb_new_device+0x9aa/0x1690 drivers/usb/core/hub.c:2708
 hub_port_connect drivers/usb/core/hub.c:5580 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5720 [inline]
 port_event drivers/usb/core/hub.c:5884 [inline]
 hub_event+0x28e8/0x4d30 drivers/usb/core/hub.c:5966
 process_one_work kernel/workqueue.c:3396 [inline]
 process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3479
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3560
 kthread+0x38b/0x480 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Freed by task 5943:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2748 [inline]
 slab_free mm/slub.c:6508 [inline]
 kfree+0x1c5/0x650 mm/slub.c:6801
 roccat_release+0x2ad/0x380 drivers/hid/hid-roccat.c:238
 __fput+0x418/0xa50 fs/file_table.c:512
 task_work_run+0x1d9/0x270 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:70 [inline]
 exit_to_user_mode_loop+0x204/0x770 kernel/entry/common.c:101
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:343 [inline]
 do_syscall_64+0x328/0x520 arch/x86/entry/syscall_64.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff8880316d8800
 which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 8 bytes inside of
 freed 1024-byte region [ffff8880316d8800, ffff8880316d8c00)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x316d8
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x4fff00000000040(head|node=1|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 04fff00000000040 ffff88801b041dc0 dead000000000100 dead000000000122
raw: 0000000000000000 0000000000080008 00000000f5000000 0000000000000000
head: 04fff00000000040 ffff88801b041dc0 dead000000000100 dead000000000122
head: 0000000000000000 0000000000080008 00000000f5000000 0000000000000000
head: 04fff00000000002 ffffffffffffff01 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000004
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5307, tgid 5307 (syz-executor), ts 97735148060
 set_page_owner include/linux/page_owner.h:33 [inline]
 post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1871
 prep_new_page mm/page_alloc.c:1879 [inline]
 get_page_from_freelist+0x2209/0x2280 mm/page_alloc.c:3943
 __alloc_frozen_pages_noprof+0x217/0x5a0 mm/page_alloc.c:5436
 alloc_slab_page mm/slub.c:3347 [inline]
 allocate_slab+0x7d/0x620 mm/slub.c:3462
 new_slab mm/slub.c:3513 [inline]
 refill_objects+0x2d5/0x350 mm/slub.c:7417
 refill_sheaf mm/slub.c:2885 [inline]
 __pcs_replace_empty_main+0x2c8/0x6c0 mm/slub.c:4774
 alloc_from_pcs mm/slub.c:4850 [inline]
 slab_alloc_node mm/slub.c:4984 [inline]
 __kmalloc_cache_noprof+0x39b/0x600 mm/slub.c:5559
 _kmalloc_noprof include/linux/slab.h:991 [inline]
 _kzalloc_noprof include/linux/slab.h:1312 [inline]
 afs_alloc_call+0x79/0x560 fs/afs/rxrpc.c:171
 afs_charge_preallocation+0x273/0x570 fs/afs/rxrpc.c:755
 afs_open_socket+0x33c/0x3f0 fs/afs/rxrpc.c:112
 afs_net_init+0x67d/0x880 fs/afs/main.c:116
 ops_init+0x35d/0x5d0 net/core/net_namespace.c:137
 setup_net+0x118/0x350 net/core/net_namespace.c:443
 copy_net_ns+0x53b/0x780 net/core/net_namespace.c:582
 create_new_namespaces+0x3f0/0x6b0 kernel/nsproxy.c:132
 unshare_nsproxy_namespaces+0x149/0x190 kernel/nsproxy.c:234
page last free pid 5308 tgid 5308 ts 97732120630 stack trace:
 reset_page_owner include/linux/page_owner.h:26 [inline]
 __free_pages_prepare mm/page_alloc.c:1418 [inline]
 __free_frozen_pages+0xc93/0xd90 mm/page_alloc.c:2962
 stack_depot_save_flags+0x41e/0x7f0 lib/stackdepot.c:735
 kasan_save_stack mm/kasan/common.c:58 [inline]
 kasan_save_track+0x4f/0x80 mm/kasan/common.c:78
 unpoison_slab_object mm/kasan/common.c:340 [inline]
 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4683 [inline]
 slab_alloc_node mm/slub.c:4996 [inline]
 kmem_cache_alloc_noprof+0x2b9/0x600 mm/slub.c:5010
 __kernfs_new_node+0xe6/0x980 fs/kernfs/dir.c:665
 kernfs_new_node+0xea/0x140 fs/kernfs/dir.c:751
 __kernfs_create_file+0x4b/0x2e0 fs/kernfs/file.c:1050
 sysfs_add_file_mode_ns+0x237/0x300 fs/sysfs/file.c:316
 create_files fs/sysfs/group.c:82 [inline]
 internal_create_group+0x679/0x1180 fs/sysfs/group.c:189
 internal_create_groups fs/sysfs/group.c:229 [inline]
 sysfs_create_groups+0x59/0x120 fs/sysfs/group.c:255
 device_add_groups drivers/base/core.c:2911 [inline]
 device_add_attrs+0xde/0x600 drivers/base/core.c:2975
 device_add+0x488/0xb80 drivers/base/core.c:3715
 wiphy_register+0x1fc8/0x2ff0 net/wireless/core.c:1158
 ieee80211_register_hw+0x3d3d/0x4a50 net/mac80211/main.c:1626
 mac80211_hwsim_new_radio+0x3258/0x56b0 drivers/net/wireless/virtual/mac80211_hwsim_main.c:6138

Memory state around the buggy address:
 ffff8880316d8700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880316d8780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8880316d8800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                      ^
 ffff8880316d8880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880316d8900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Crashes (20):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/09/15 21:25 upstream f6e7b42bf05b f41e228a .config console log report syz / log [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-use-after-free Read in roccat_disconnect
2026/09/21 17:59 upstream 93f51579e7df 853b104b .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root KASAN: slab-use-after-free Read in roccat_disconnect
2026/09/05 01:34 upstream bc35965f6940 3f042c7b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root KASAN: slab-use-after-free Read in roccat_disconnect
2026/09/05 01:29 upstream bc35965f6940 3f042c7b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root KASAN: slab-use-after-free Read in roccat_disconnect
2026/09/02 04:04 upstream 786262be6048 587f6b29 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root KASAN: slab-use-after-free Read in roccat_disconnect
2026/09/02 03:08 upstream 786262be6048 587f6b29 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root KASAN: slab-use-after-free Read in roccat_disconnect
2026/09/22 21:46 upstream c4e9f74da438 3e2106e5 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-use-after-free Read in roccat_disconnect
2026/09/22 21:46 upstream c4e9f74da438 3e2106e5 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-use-after-free Read in roccat_disconnect
2026/09/21 02:06 upstream 518e5b794c06 853b104b .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: slab-use-after-free Read in roccat_disconnect
2026/09/21 02:05 upstream 518e5b794c06 853b104b .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: slab-use-after-free Read in roccat_disconnect
2026/09/21 02:05 upstream 518e5b794c06 853b104b .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: slab-use-after-free Read in roccat_disconnect
2026/09/07 19:11 upstream df2908090cda 5e4626f5 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: slab-use-after-free Read in roccat_disconnect
2026/09/07 19:06 upstream df2908090cda 5e4626f5 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: slab-use-after-free Read in roccat_disconnect
2026/09/07 19:05 upstream df2908090cda 5e4626f5 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: slab-use-after-free Read in roccat_disconnect
2026/09/04 18:33 upstream bc35965f6940 44dda43b .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-use-after-free Read in roccat_disconnect
2026/09/04 18:32 upstream bc35965f6940 44dda43b .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-use-after-free Read in roccat_disconnect
2026/09/01 20:31 upstream bf1079577a11 587f6b29 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-use-after-free Read in roccat_disconnect
2026/09/01 20:31 upstream bf1079577a11 587f6b29 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-use-after-free Read in roccat_disconnect
2026/09/01 20:30 upstream bf1079577a11 587f6b29 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-use-after-free Read in roccat_disconnect
2026/08/31 18:43 upstream cee9395acd80 00e9c810 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: slab-use-after-free Read in roccat_disconnect
* Struck through repros no longer work on HEAD.