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

Status: upstream: reported on 2026/10/22 21:24
Reported-by: syzbot+64f9e5edb744b6172626@syzkaller.appspotmail.com
First crash: 2d15h, last: 1d22h
▶ ▼ Similar bugs (5)
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 26d 42d 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 32d 52d 0/29 upstream: reported C repro on 2026/09/02 18:57
android-5-10 KASAN: use-after-free Read in roccat_disconnect 19 syz, C 4 21d 37d 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 8 2d08h 43d 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 7 2d08h 2d21h 0/2 upstream: reported C repro on 2026/10/22 14:43

Sample crash report:
usb 3-1: config 0 descriptor??
savu 0003:1E7D:2D5A.0001: hidraw0: USB HID v0.00 Device [HID 1e7d:2d5a] on usb-dummy_hcd.2-1/input0
usb 3-1: USB disconnect, device number 2
==================================================================
BUG: KASAN: slab-use-after-free in roccat_disconnect+0x23a/0x240 drivers/hid/hid-roccat.c:382
Read of size 4 at addr ffff8880272a7008 by task kworker/1:0/23

CPU: 1 PID: 23 Comm: kworker/1:0 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
Workqueue: usb_hub_wq hub_event
Call Trace:
 <TASK>
 dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:364 [inline]
 print_report+0xa8/0x210 mm/kasan/report.c:468
 kasan_report+0x117/0x150 mm/kasan/report.c:581
 roccat_disconnect+0x23a/0x240 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+0xbe/0x1c0 drivers/hid/hid-core.c:2772
 device_remove drivers/base/dd.c:626 [inline]
 __device_release_driver drivers/base/dd.c:1351 [inline]
 device_release_driver_internal+0x408/0x6f0 drivers/base/dd.c:1374
 bus_remove_device+0x43b/0x520 drivers/base/bus.c:624
 device_del+0x51f/0x910 drivers/base/core.c:3957
 hid_remove_device drivers/hid/hid-core.c:2950 [inline]
 hid_destroy_device+0x6a/0x100 drivers/hid/hid-core.c:2970
 usbhid_disconnect+0x9f/0xc0 drivers/hid/usbhid/hid-core.c:1475
 usb_unbind_interface+0x204/0x870 drivers/usb/core/driver.c:457
 device_remove drivers/base/dd.c:628 [inline]
 __device_release_driver drivers/base/dd.c:1351 [inline]
 device_release_driver_internal+0x458/0x6f0 drivers/base/dd.c:1374
 bus_remove_device+0x43b/0x520 drivers/base/bus.c:624
 device_del+0x51f/0x910 drivers/base/core.c:3957
 usb_disable_device+0x3ee/0x8a0 drivers/usb/core/message.c:1480
 usb_disconnect+0x340/0x8a0 drivers/usb/core/hub.c:2325
 hub_port_connect drivers/usb/core/hub.c:5379 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5679 [inline]
 port_event drivers/usb/core/hub.c:5843 [inline]
 hub_event+0x1d69/0x4a80 drivers/usb/core/hub.c:5925
 process_one_work kernel/workqueue.c:2657 [inline]
 process_scheduled_works+0xa60/0x1600 kernel/workqueue.c:2734
 worker_thread+0xa5e/0xfe0 kernel/workqueue.c:2815
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>

Allocated by task 23:
 kasan_save_stack mm/kasan/common.c:46 [inline]
 kasan_set_track+0x4e/0x70 mm/kasan/common.c:53
 ____kasan_kmalloc mm/kasan/common.c:375 [inline]
 __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:384
 kmalloc include/linux/slab.h:600 [inline]
 kzalloc include/linux/slab.h:721 [inline]
 roccat_connect+0x5d/0x490 drivers/hid/hid-roccat.c:315
 savu_init_specials drivers/hid/hid-roccat-savu.c:84 [inline]
 savu_probe+0x18e/0x330 drivers/hid/hid-roccat-savu.c:134
 __hid_device_probe drivers/hid/hid-core.c:2714 [inline]
 hid_device_probe+0x283/0x5b0 drivers/hid/hid-core.c:2753
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x24a/0xae0 drivers/base/dd.c:717
 __driver_probe_device+0x1f5/0x390 drivers/base/dd.c:879
 driver_probe_device+0x4f/0x420 drivers/base/dd.c:909
 __device_attach_driver+0x2ca/0x510 drivers/base/dd.c:1037
 bus_for_each_drv+0x252/0x2e0 drivers/base/bus.c:459
 __device_attach+0x2c1/0x420 drivers/base/dd.c:1109
 bus_probe_device+0x180/0x260 drivers/base/bus.c:580
 device_add+0x87c/0xc40 drivers/base/core.c:3768
 hid_add_device+0x365/0x500 drivers/hid/hid-core.c:2899
 usbhid_probe+0xe43/0x1260 drivers/hid/usbhid/hid-core.c:1448
 usb_probe_interface+0x6eb/0xcf0 drivers/usb/core/driver.c:395
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x24a/0xae0 drivers/base/dd.c:717
 __driver_probe_device+0x1f5/0x390 drivers/base/dd.c:879
 driver_probe_device+0x4f/0x420 drivers/base/dd.c:909
 __device_attach_driver+0x2ca/0x510 drivers/base/dd.c:1037
 bus_for_each_drv+0x252/0x2e0 drivers/base/bus.c:459
 __device_attach+0x2c1/0x420 drivers/base/dd.c:1109
 bus_probe_device+0x180/0x260 drivers/base/bus.c:580
 device_add+0x87c/0xc40 drivers/base/core.c:3768
 usb_set_configuration+0x1bad/0x2220 drivers/usb/core/message.c:2271
 usb_generic_driver_probe+0x8d/0x150 drivers/usb/core/generic.c:238
 usb_probe_device+0x12a/0x260 drivers/usb/core/driver.c:291
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x24a/0xae0 drivers/base/dd.c:717
 __driver_probe_device+0x1f5/0x390 drivers/base/dd.c:879
 driver_probe_device+0x4f/0x420 drivers/base/dd.c:909
 __device_attach_driver+0x2ca/0x510 drivers/base/dd.c:1037
 bus_for_each_drv+0x252/0x2e0 drivers/base/bus.c:459
 __device_attach+0x2c1/0x420 drivers/base/dd.c:1109
 bus_probe_device+0x180/0x260 drivers/base/bus.c:580
 device_add+0x87c/0xc40 drivers/base/core.c:3768
 usb_new_device+0x995/0x1550 drivers/usb/core/hub.c:2670
 hub_port_connect drivers/usb/core/hub.c:5539 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5679 [inline]
 port_event drivers/usb/core/hub.c:5843 [inline]
 hub_event+0x29d5/0x4a80 drivers/usb/core/hub.c:5925
 process_one_work kernel/workqueue.c:2657 [inline]
 process_scheduled_works+0xa60/0x1600 kernel/workqueue.c:2734
 worker_thread+0xa5e/0xfe0 kernel/workqueue.c:2815
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293

Freed by task 5891:
 kasan_save_stack mm/kasan/common.c:46 [inline]
 kasan_set_track+0x4e/0x70 mm/kasan/common.c:53
 kasan_save_free_info+0x28/0x40 mm/kasan/generic.c:522
 ____kasan_slab_free+0x126/0x1f0 mm/kasan/common.c:237
 kasan_slab_free include/linux/kasan.h:164 [inline]
 slab_free_hook mm/slub.c:1833 [inline]
 slab_free_freelist_hook+0x154/0x240 mm/slub.c:1859
 slab_free mm/slub.c:3853 [inline]
 __kmem_cache_free+0xba/0x1f0 mm/slub.c:3866
 roccat_release+0x2aa/0x370 drivers/hid/hid-roccat.c:238
 __fput+0x221/0x940 fs/file_table.c:418
 task_work_run+0x1d4/0x260 kernel/task_work.c:245
 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:294 [inline]
 syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:305
 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

The buggy address belongs to the object at ffff8880272a7000
 which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 8 bytes inside of
 freed 1024-byte region [ffff8880272a7000, ffff8880272a7400)

The buggy address belongs to the physical page:
page:ffffea00009ca800 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x272a0
head:ffffea00009ca800 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000840 ffff888018c41dc0 dead000000000122 0000000000000000
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 0x152820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_HARDWALL), pid 142, tgid 142 (kworker/u4:5), ts 92578323805, free_ts 92129098874
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x1c1/0x200 mm/page_alloc.c:1582
 prep_new_page mm/page_alloc.c:1589 [inline]
 get_page_from_freelist+0x2181/0x22a0 mm/page_alloc.c:3221
 __alloc_pages+0x1f0/0x460 mm/page_alloc.c:4501
 alloc_slab_page+0x5d/0x180 mm/slub.c:1903
 allocate_slab mm/slub.c:2050 [inline]
 new_slab+0x87/0x2d0 mm/slub.c:2103
 ___slab_alloc+0xc5c/0x12f0 mm/slub.c:3275
 __slab_alloc mm/slub.c:3361 [inline]
 __slab_alloc_node mm/slub.c:3414 [inline]
 slab_alloc_node mm/slub.c:3508 [inline]
 __kmem_cache_alloc_node+0x122/0x260 mm/slub.c:3557
 __do_kmalloc_node mm/slab_common.c:1006 [inline]
 __kmalloc+0xa7/0x240 mm/slab_common.c:1020
 kmalloc include/linux/slab.h:604 [inline]
 kzalloc include/linux/slab.h:721 [inline]
 neigh_alloc net/core/neighbour.c:495 [inline]
 ___neigh_create+0x6f4/0x23d0 net/core/neighbour.c:649
 ip6_finish_output2+0x1492/0x1550 net/ipv6/ip6_output.c:130
 NF_HOOK_COND include/linux/netfilter.h:305 [inline]
 ip6_output+0x33b/0x530 net/ipv6/ip6_output.c:242
 dst_output include/net/dst.h:470 [inline]
 NF_HOOK include/linux/netfilter.h:316 [inline]
 ndisc_send_skb+0xbb9/0x1480 net/ipv6/ndisc.c:513
 ndisc_send_ns+0xd8/0x160 net/ipv6/ndisc.c:671
 addrconf_dad_work+0xa27/0x1550 net/ipv6/addrconf.c:4283
 process_one_work kernel/workqueue.c:2657 [inline]
 process_scheduled_works+0xa60/0x1600 kernel/workqueue.c:2734
 worker_thread+0xa5e/0xfe0 kernel/workqueue.c:2815
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1182 [inline]
 free_unref_page_prepare+0x7d7/0x8f0 mm/page_alloc.c:2366
 free_unref_page+0x32/0x2e0 mm/page_alloc.c:2459
 discard_slab mm/slub.c:2149 [inline]
 __unfreeze_partials+0x1cf/0x210 mm/slub.c:2689
 put_cpu_partial+0x17c/0x250 mm/slub.c:2765
 __slab_free+0x319/0x400 mm/slub.c:3723
 qlink_free mm/kasan/quarantine.c:166 [inline]
 qlist_free_all+0x75/0xd0 mm/kasan/quarantine.c:185
 kasan_quarantine_reduce+0x143/0x160 mm/kasan/quarantine.c:292
 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:306
 kasan_slab_alloc include/linux/kasan.h:188 [inline]
 slab_post_alloc_hook+0x6a/0x4d0 mm/slab.h:770
 slab_alloc_node mm/slub.c:3518 [inline]
 slab_alloc mm/slub.c:3526 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3533 [inline]
 kmem_cache_alloc+0x17e/0x2d0 mm/slub.c:3542
 vm_area_alloc+0x24/0x1d0 kernel/fork.c:487
 __mmap_region mm/mmap.c:2778 [inline]
 mmap_region+0xcfa/0x2090 mm/mmap.c:2949
 do_mmap+0x98f/0x10a0 mm/mmap.c:1393
 vm_mmap_pgoff+0x1c4/0x3f0 mm/util.c:573
 ksys_mmap_pgoff+0x4c9/0x720 mm/mmap.c:1439
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76

Memory state around the buggy address:
 ffff8880272a6f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880272a6f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8880272a7000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                      ^
 ffff8880272a7080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880272a7100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/10/23 13:32 linux-6.6.y 0aebf2870d53 d566bfda .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in roccat_disconnect
2026/10/22 21:24 linux-6.6.y 0aebf2870d53 b55fad29 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in roccat_disconnect
* Struck through repros no longer work on HEAD.