From: syzbot <syzbot+cade843a1e4af0651f5e@syzkaller.appspotmail.com>
To: gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org,
linux-usb@vger.kernel.org, syzkaller-bugs@googlegroups.com
Subject: [syzbot] [usb?] KASAN: slab-use-after-free Write in usb_giveback_urb_bh
Date: Sat, 22 Aug 2026 18:43:35 -0700 [thread overview]
Message-ID: <6a8a5047.dbb3a75c.13dd47.003e.GAE@google.com> (raw)
Hello,
syzbot found the following issue on:
HEAD commit: a4ff2be345d0 Merge tag 'v7.3-p1' of git://git.kernel.org/p..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1723ee79580000
kernel config: https://syzkaller.appspot.com/x/.config?x=2823969bbc36a8c4
dashboard link: https://syzkaller.appspot.com/bug?extid=cade843a1e4af0651f5e
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/058e33081021/disk-a4ff2be3.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/33ebad2a63ba/vmlinux-a4ff2be3.xz
kernel image: https://storage.googleapis.com/syzbot-assets/6e7b43fa415b/bzImage-a4ff2be3.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+cade843a1e4af0651f5e@syzkaller.appspotmail.com
==================================================================
BUG: KASAN: slab-use-after-free in usb_giveback_urb_bh+0x2b9/0x440 drivers/usb/core/hcd.c:1692
Write of size 8 at addr ffff888029ab0338 by task ksoftirqd/0/15
CPU: 0 UID: 0 PID: 15 Comm: ksoftirqd/0 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
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
usb_giveback_urb_bh+0x2b9/0x440 drivers/usb/core/hcd.c:1692
process_one_work kernel/workqueue.c:3322 [inline]
process_scheduled_works+0xa88/0x14c0 kernel/workqueue.c:3405
bh_worker+0x46a/0x880 kernel/workqueue.c:3708
tasklet_hi_action+0xf/0x70 kernel/softirq.c:1003
handle_softirqs+0x1da/0x6d0 kernel/softirq.c:645
run_ksoftirqd+0x53/0x190 kernel/softirq.c:1108
smpboot_thread_fn+0x565/0xa70 kernel/smpboot.c:160
kthread+0x38b/0x470 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 1:
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]
__do_kmalloc_node mm/slub.c:5334 [inline]
__kmalloc_noprof+0x422/0x780 mm/slub.c:5359
_kmalloc_noprof include/linux/slab.h:992 [inline]
_kzalloc_noprof include/linux/slab.h:1309 [inline]
__usb_create_hcd+0x67/0x900 drivers/usb/core/hcd.c:2566
dummy_hcd_probe+0xf6/0x270 drivers/usb/gadget/udc/dummy_hcd.c:2717
platform_probe+0xf9/0x190 drivers/base/platform.c:1507
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+0x25b/0x2f0 drivers/base/bus.c:500
__device_attach+0x2c7/0x450 drivers/base/dd.c:1098
device_initial_probe+0xa1/0xd0 drivers/base/dd.c:1153
bus_probe_device+0x12d/0x220 drivers/base/bus.c:620
device_add+0x7d7/0xb80 drivers/base/core.c:3776
platform_device_add+0x4bd/0x860 drivers/base/platform.c:833
dummy_hcd_init+0x667/0xd00 drivers/usb/gadget/udc/dummy_hcd.c:2873
do_one_initcall+0x250/0x870 init/main.c:1353
do_initcall_level+0x10a/0x1a0 init/main.c:1415
do_initcalls+0x59/0xa0 init/main.c:1431
kernel_init_freeable+0x29d/0x3e0 init/main.c:1666
kernel_init+0x22/0x1d0 init/main.c:1556
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 8989:
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:2677 [inline]
slab_free mm/slub.c:6377 [inline]
kfree+0x1c5/0x6d0 mm/slub.c:6692
usb_release_dev+0x57/0xe0 drivers/usb/core/usb.c:497
device_release+0xc4/0x1f0 drivers/base/core.c:-1
kobject_cleanup lib/kobject.c:689 [inline]
kobject_release lib/kobject.c:720 [inline]
kref_put include/linux/kref.h:65 [inline]
kobject_put+0x222/0x550 lib/kobject.c:737
usbdev_open+0x1f0/0x790 drivers/usb/core/devio.c:1086
chrdev_open+0x4dc/0x600 fs/char_dev.c:411
do_dentry_open+0x849/0x1420 fs/open.c:996
vfs_open+0x3b/0x350 fs/open.c:1101
do_open fs/namei.c:4837 [inline]
path_openat+0x1448/0x1d60 fs/namei.c:5000
do_file_open+0x23e/0x4a0 fs/namei.c:5029
do_sys_openat2+0x115/0x200 fs/open.c:1417
do_sys_open fs/open.c:1423 [inline]
__do_sys_openat fs/open.c:1439 [inline]
__se_sys_openat fs/open.c:1434 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1434
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Last potentially related work creation:
kasan_save_stack+0x3e/0x60 mm/kasan/common.c:57
kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556
insert_work+0x3d/0x330 kernel/workqueue.c:2226
__queue_work+0xd1e/0x10f0 kernel/workqueue.c:2401
queue_work_on+0x106/0x1d0 kernel/workqueue.c:2452
usb_rh_urb_dequeue drivers/usb/core/hcd.c:845 [inline]
unlink1+0x33d/0x3e0 drivers/usb/core/hcd.c:1580
usb_hcd_flush_endpoint+0x167/0x440 drivers/usb/core/hcd.c:1794
usb_disable_endpoint drivers/usb/core/message.c:1362 [inline]
usb_disable_interface+0x279/0x350 drivers/usb/core/message.c:1408
usb_unbind_interface+0x265/0x9f0 drivers/usb/core/driver.c:456
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+0x449/0x560 drivers/base/bus.c:664
device_del+0x528/0x8f0 drivers/base/core.c:3965
usb_disable_device+0x3d4/0x8d0 drivers/usb/core/message.c:1478
usb_disconnect+0x32d/0x990 drivers/usb/core/hub.c:2345
usb_remove_hcd+0x275/0x670 drivers/usb/core/hcd.c:3059
dummy_hcd_remove+0xed/0x130 drivers/usb/gadget/udc/dummy_hcd.c:2761
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
unbind_store+0x1a4/0x1d0 drivers/base/bus.c:244
kernfs_fop_write_iter+0x3a5/0x540 fs/kernfs/file.c:345
new_sync_write fs/read_write.c:595 [inline]
vfs_write+0x61e/0xbb0 fs/read_write.c:687
ksys_write+0x156/0x270 fs/read_write.c:739
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Second to last potentially related work creation:
kasan_save_stack+0x3e/0x60 mm/kasan/common.c:57
kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556
insert_work+0x3d/0x330 kernel/workqueue.c:2226
__queue_work+0xd1e/0x10f0 kernel/workqueue.c:2401
queue_work_on+0x106/0x1d0 kernel/workqueue.c:2452
rh_call_control drivers/usb/core/hcd.c:706 [inline]
rh_urb_enqueue drivers/usb/core/hcd.c:817 [inline]
usb_hcd_submit_urb+0xa2d/0x1b40 drivers/usb/core/hcd.c:1538
usb_start_wait_urb+0x13f/0x5b0 drivers/usb/core/message.c:62
usb_internal_control_msg drivers/usb/core/message.c:117 [inline]
usb_control_msg+0x234/0x3e0 drivers/usb/core/message.c:167
usb_clear_port_feature drivers/usb/core/hub.c:456 [inline]
port_event drivers/usb/core/hub.c:5773 [inline]
hub_event+0x832/0x4cf0 drivers/usb/core/hub.c:5961
process_one_work kernel/workqueue.c:3322 [inline]
process_scheduled_works+0xa88/0x14c0 kernel/workqueue.c:3405
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486
kthread+0x38b/0x470 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
The buggy address belongs to the object at ffff888029ab0000
which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 824 bytes inside of
freed 2048-byte region [ffff888029ab0000, ffff888029ab0800)
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888029ab6000 pfn:0x29ab0
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x80000000000240(workingset|head|node=0|zone=1)
page_type: f5(slab)
raw: 0080000000000240 ffff88813ffb2000 ffffea0000a7ce10 ffffea0000a55a10
raw: ffff888029ab6000 0000000800080006 00000000f5000000 0000000000000000
head: 0080000000000240 ffff88813ffb2000 ffffea0000a7ce10 ffffea0000a55a10
head: ffff888029ab6000 0000000800080006 00000000f5000000 0000000000000000
head: 0080000000000003 fffffffffffffe01 00000000ffffffff 00000000ffffffff
head: 0000000000000000 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 12235747769, free_ts 11878976125
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1859
prep_new_page mm/page_alloc.c:1867 [inline]
get_page_from_freelist+0x2630/0x26a0 mm/page_alloc.c:3946
__alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5304
alloc_slab_page mm/slub.c:3266 [inline]
allocate_slab+0x79/0x5e0 mm/slub.c:3380
new_slab mm/slub.c:3426 [inline]
refill_objects+0x2d8/0x350 mm/slub.c:7310
refill_sheaf mm/slub.c:2804 [inline]
__pcs_replace_empty_main+0x334/0x690 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+0x54c/0x780 mm/slub.c:5359
_kmalloc_noprof include/linux/slab.h:992 [inline]
_kzalloc_noprof include/linux/slab.h:1309 [inline]
platform_device_alloc+0x39/0x260 drivers/base/platform.c:634
dummy_hcd_init+0x2c9/0xd00 drivers/usb/gadget/udc/dummy_hcd.c:2841
do_one_initcall+0x250/0x870 init/main.c:1353
do_initcall_level+0x10a/0x1a0 init/main.c:1415
do_initcalls+0x59/0xa0 init/main.c:1431
kernel_init_freeable+0x29d/0x3e0 init/main.c:1666
kernel_init+0x22/0x1d0 init/main.c:1556
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
page last free pid 100 tgid 100 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
__free_pages_prepare mm/page_alloc.c:1406 [inline]
free_pages_prepare+0x946/0xa40 mm/page_alloc.c:1451
__free_contig_range_common+0x174/0x340 mm/page_alloc.c:6897
__free_contig_range mm/page_alloc.c:6942 [inline]
free_pages_bulk+0x48/0x120 mm/page_alloc.c:5257
vm_area_free_pages mm/vmalloc.c:3461 [inline]
vfree+0x26d/0x510 mm/vmalloc.c:3510
delayed_vfree_work+0x55/0x80 mm/vmalloc.c:3414
process_one_work kernel/workqueue.c:3322 [inline]
process_scheduled_works+0xa88/0x14c0 kernel/workqueue.c:3405
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486
kthread+0x38b/0x470 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
Memory state around the buggy address:
ffff888029ab0200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888029ab0280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888029ab0300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888029ab0380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888029ab0400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.
syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title
If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)
If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report
If you want to undo deduplication, reply with:
#syz undup
reply other threads:[~2026-08-23 1:43 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=6a8a5047.dbb3a75c.13dd47.003e.GAE@google.com \
--to=syzbot+cade843a1e4af0651f5e@syzkaller.appspotmail.com \
--cc=gregkh@linuxfoundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-usb@vger.kernel.org \
--cc=syzkaller-bugs@googlegroups.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.