KASAN: use-after-free Read in roccat_disconnect

Status: upstream: reported C repro on 2026/10/26 05:36
Reported-by: syzbot+9fab75fa4229812edfaa@syzkaller.appspotmail.com
First crash: 7d13h, last: 19h42m
▶ ▼ Similar bugs (7)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 KASAN: use-after-free Read in roccat_disconnect 19 syz, C 7 1h44m 21h19m 0/3 upstream: reported C repro on 2026/11/01 22:08
android-5-10 KASAN: use-after-free Read in roccat_disconnect 19 syz, C 10 7h58m 45d 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 10 1d11h 52d 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 12 3h37m 11d 0/2 upstream: reported C repro on 2026/10/22 14:43
linux-6.6 KASAN: slab-use-after-free Read in roccat_disconnect 19 syz, C 9 1d04h 10d 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 29 3h28m 50d 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 40d 61d 2/29 upstream: reported C repro on 2026/09/02 18:57

Sample crash report:
usb 1-1: New USB device strings: Mfr=0, Product=0, SerialNumber=0
usb 1-1: config 0 descriptor??
savu 0003:1E7D:2D5A.0003: hidraw0: USB HID v0.00 Device [HID 1e7d:2d5a] on usb-dummy_hcd.0-1/input0
usb 1-1: USB disconnect, device number 4
==================================================================
BUG: KASAN: use-after-free in roccat_disconnect+0x236/0x240 drivers/hid/hid-roccat.c:382
Read of size 4 at addr ffff88807ac0f808 by task kworker/1:17/4344

CPU: 1 PID: 4344 Comm: kworker/1:17 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+0x188/0x250 lib/dump_stack.c:106
 print_address_description+0x60/0x2d0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:434 [inline]
 kasan_report+0xdf/0x130 mm/kasan/report.c:451
 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:2435
 __device_release_driver drivers/base/dd.c:1247 [inline]
 device_release_driver_internal+0x44c/0x710 drivers/base/dd.c:1282
 bus_remove_device+0x2dd/0x400 drivers/base/bus.c:531
 device_del+0x63f/0xa80 drivers/base/core.c:3615
 hid_remove_device drivers/hid/hid-core.c:2611 [inline]
 hid_destroy_device+0x66/0x100 drivers/hid/hid-core.c:2630
 usbhid_disconnect+0x9b/0xc0 drivers/hid/usbhid/hid-core.c:1470
 usb_unbind_interface+0x203/0x870 drivers/usb/core/driver.c:458
 __device_release_driver drivers/base/dd.c:1249 [inline]
 device_release_driver_internal+0x487/0x710 drivers/base/dd.c:1282
 bus_remove_device+0x2dd/0x400 drivers/base/bus.c:531
 device_del+0x63f/0xa80 drivers/base/core.c:3615
 usb_disable_device+0x3e7/0x8a0 drivers/usb/core/message.c:1478
 usb_disconnect+0x33c/0x8a0 drivers/usb/core/hub.c:2297
 hub_port_connect drivers/usb/core/hub.c:5351 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5647 [inline]
 port_event drivers/usb/core/hub.c:5809 [inline]
 hub_event+0x1d64/0x5260 drivers/usb/core/hub.c:5891
 process_one_work+0x867/0xff0 kernel/workqueue.c:2310
 worker_thread+0xad7/0x12a0 kernel/workqueue.c:2457
 kthread+0x42e/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>

Allocated by task 4344:
 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 mm/kasan/common.c:513 [inline]
 __kasan_kmalloc+0xaf/0xe0 mm/kasan/common.c:522
 kmalloc include/linux/slab.h:607 [inline]
 kzalloc include/linux/slab.h:738 [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:2377 [inline]
 hid_device_probe+0x2cb/0x590 drivers/hid/hid-core.c:2416
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x276/0xc70 drivers/base/dd.c:595
 __driver_probe_device+0x1f5/0x390 drivers/base/dd.c:775
 driver_probe_device+0x4f/0x420 drivers/base/dd.c:805
 __device_attach_driver+0x2b0/0x500 drivers/base/dd.c:927
 bus_for_each_drv+0x184/0x210 drivers/base/bus.c:429
 __device_attach+0x2a7/0x480 drivers/base/dd.c:999
 bus_probe_device+0xba/0x1d0 drivers/base/bus.c:489
 device_add+0xbcf/0x1050 drivers/base/core.c:3427
 hid_add_device+0x361/0x500 drivers/hid/hid-core.c:2562
 usbhid_probe+0xbc5/0xf50 drivers/hid/usbhid/hid-core.c:1443
 usb_probe_interface+0x5be/0xae0 drivers/usb/core/driver.c:396
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x276/0xc70 drivers/base/dd.c:595
 __driver_probe_device+0x1f5/0x390 drivers/base/dd.c:775
 driver_probe_device+0x4f/0x420 drivers/base/dd.c:805
 __device_attach_driver+0x2b0/0x500 drivers/base/dd.c:927
 bus_for_each_drv+0x184/0x210 drivers/base/bus.c:429
 __device_attach+0x2a7/0x480 drivers/base/dd.c:999
 bus_probe_device+0xba/0x1d0 drivers/base/bus.c:489
 device_add+0xbcf/0x1050 drivers/base/core.c:3427
 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:293
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x276/0xc70 drivers/base/dd.c:595
 __driver_probe_device+0x1f5/0x390 drivers/base/dd.c:775
 driver_probe_device+0x4f/0x420 drivers/base/dd.c:805
 __device_attach_driver+0x2b0/0x500 drivers/base/dd.c:927
 bus_for_each_drv+0x184/0x210 drivers/base/bus.c:429
 __device_attach+0x2a7/0x480 drivers/base/dd.c:999
 bus_probe_device+0xba/0x1d0 drivers/base/bus.c:489
 device_add+0xbcf/0x1050 drivers/base/core.c:3427
 usb_new_device+0x9f6/0x15d0 drivers/usb/core/hub.c:2642
 hub_port_connect drivers/usb/core/hub.c:5507 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5647 [inline]
 port_event drivers/usb/core/hub.c:5809 [inline]
 hub_event+0x2b8d/0x5260 drivers/usb/core/hub.c:5891
 process_one_work+0x867/0xff0 kernel/workqueue.c:2310
 worker_thread+0xad7/0x12a0 kernel/workqueue.c:2457
 kthread+0x42e/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287

Freed by task 4417:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:46
 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360
 ____kasan_slab_free+0xd5/0x110 mm/kasan/common.c:366
 kasan_slab_free include/linux/kasan.h:230 [inline]
 slab_free_hook mm/slub.c:1710 [inline]
 slab_free_freelist_hook+0xec/0x170 mm/slub.c:1736
 slab_free mm/slub.c:3504 [inline]
 kfree+0xef/0x2a0 mm/slub.c:4564
 roccat_release+0x2a6/0x370 drivers/hid/hid-roccat.c:238
 __fput+0x212/0x8c0 fs/file_table.c:311
 task_work_run+0x125/0x1a0 kernel/task_work.c:188
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop+0x10f/0x130 kernel/entry/common.c:184
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:217
 __syscall_exit_to_user_mode_work kernel/entry/common.c:299 [inline]
 syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:310
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

The buggy address belongs to the object at ffff88807ac0f800
 which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 8 bytes inside of
 1024-byte region [ffff88807ac0f800, ffff88807ac0fc00)
The buggy address belongs to the page:
page:ffffea0001eb0200 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7ac08
head:ffffea0001eb0200 order:3 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 ffffea0001ecf600 0000000500000005 ffff888017841dc0
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 4181, ts 60496512751, free_ts 60423112030
 prep_new_page mm/page_alloc.c:2426 [inline]
 get_page_from_freelist+0x24f6/0x2670 mm/page_alloc.c:4192
 __alloc_pages+0x1ee/0x480 mm/page_alloc.c:5501
 alloc_slab_page mm/slub.c:1780 [inline]
 allocate_slab mm/slub.c:1917 [inline]
 new_slab+0xc0/0x4b0 mm/slub.c:1980
 ___slab_alloc+0x807/0xdd0 mm/slub.c:3013
 __slab_alloc mm/slub.c:3100 [inline]
 slab_alloc_node mm/slub.c:3191 [inline]
 __kmalloc_node_track_caller+0x13d/0x3a0 mm/slub.c:4963
 kmalloc_reserve net/core/skbuff.c:356 [inline]
 __alloc_skb+0x22c/0x750 net/core/skbuff.c:427
 alloc_skb_fclone include/linux/skbuff.h:1212 [inline]
 sk_stream_alloc_skb+0x204/0xb50 net/ipv4/tcp.c:892
 tcp_sendmsg_locked+0xcbb/0x3330 net/ipv4/tcp.c:1317
 tcp_sendmsg+0x2b/0x40 net/ipv4/tcp.c:1460
 sock_sendmsg_nosec net/socket.c:706 [inline]
 __sock_sendmsg net/socket.c:718 [inline]
 sock_write_iter+0x2a6/0x3a0 net/socket.c:1090
 call_write_iter include/linux/fs.h:2179 [inline]
 new_sync_write fs/read_write.c:507 [inline]
 vfs_write+0x748/0xd70 fs/read_write.c:594
 ksys_write+0x153/0x260 fs/read_write.c:647
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
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+0x637/0x6c0 mm/page_alloc.c:3317
 free_unref_page+0x8f/0x2a0 mm/page_alloc.c:3396
 skb_free_frag include/linux/skbuff.h:3067 [inline]
 skb_free_head net/core/skbuff.c:653 [inline]
 skb_release_data+0x676/0x830 net/core/skbuff.c:677
 skb_release_all net/core/skbuff.c:742 [inline]
 __kfree_skb+0x4c/0x60 net/core/skbuff.c:756
 sk_eat_skb include/net/sock.h:2793 [inline]
 tcp_recvmsg_locked+0x143d/0x2690 net/ipv4/tcp.c:2520
 tcp_recvmsg+0x22a/0x760 net/ipv4/tcp.c:2566
 inet_recvmsg+0x146/0x200 net/ipv4/af_inet.c:868
 sock_recvmsg_nosec net/socket.c:969 [inline]
 sock_recvmsg net/socket.c:987 [inline]
 sock_read_iter+0x2c2/0x380 net/socket.c:1068
 call_read_iter include/linux/fs.h:2173 [inline]
 new_sync_read fs/read_write.c:404 [inline]
 vfs_read+0x75e/0xd50 fs/read_write.c:485
 ksys_read+0x153/0x260 fs/read_write.c:623
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

Memory state around the buggy address:
 ffff88807ac0f700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88807ac0f780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88807ac0f800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                      ^
 ffff88807ac0f880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88807ac0f900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Crashes (7):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/11/01 23:45 linux-5.15.y 700e62ea909a 25a0ae84 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in roccat_disconnect
2026/10/30 05:22 linux-5.15.y 792fbe1537d8 b498adee .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in roccat_disconnect
2026/10/28 04:57 linux-5.15.y 792fbe1537d8 96923c60 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in roccat_disconnect
2026/10/26 09:56 linux-5.15.y 792fbe1537d8 1d9ca40b .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in roccat_disconnect
2026/10/26 08:00 linux-5.15.y 792fbe1537d8 1d9ca40b .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in roccat_disconnect
2026/10/28 16:39 linux-5.15.y 792fbe1537d8 858db2ec .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in roccat_disconnect
2026/10/26 05:36 linux-5.15.y 792fbe1537d8 1d9ca40b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in roccat_disconnect
* Struck through repros no longer work on HEAD.