From: syzbot <syzbot+bc537ca7a0efe33988eb@syzkaller.appspotmail.com>
To: bentiss@kernel.org, jikos@kernel.org,
linux-input@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-usb@vger.kernel.org, syzkaller-bugs@googlegroups.com
Subject: Re: [syzbot] [input?] [usb?] KASAN: slab-use-after-free Read in report_descriptor_read
Date: Sat, 15 Aug 2026 20:03:26 -0700 [thread overview]
Message-ID: <6a81287e.10853dc7.22f513.000c.GAE@google.com> (raw)
In-Reply-To: <683199ed.a70a0220.29d4a0.07f6.GAE@google.com>
syzbot has found a reproducer for the following issue on:
HEAD commit: bdab5605259b usb: gadget: uvc: fix dangling pointers in uv..
git tree: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing
console output: https://syzkaller.appspot.com/x/log.txt?x=163fb279580000
kernel config: https://syzkaller.appspot.com/x/.config?x=8bdeea7ee6735f91
dashboard link: https://syzkaller.appspot.com/bug?extid=bc537ca7a0efe33988eb
compiler: gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1108aa25580000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/2cb2fdbdd7b7/disk-bdab5605.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/f801d31c2001/vmlinux-bdab5605.xz
kernel image: https://storage.googleapis.com/syzbot-assets/9002a6e0ae14/bzImage-bdab5605.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+bc537ca7a0efe33988eb@syzkaller.appspotmail.com
==================================================================
BUG: KASAN: slab-use-after-free in report_descriptor_read+0xbb/0x100 drivers/hid/hid-core.c:2272
Read of size 24 at addr ffff888120aa1480 by task fido_id/6160
CPU: 1 UID: 0 PID: 6160 Comm: fido_id Not tainted syzkaller #0 PREEMPT(lazy)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0x13d/0x4b0 mm/kasan/report.c:482
kasan_report+0xdf/0x1c0 mm/kasan/report.c:595
check_region_inline mm/kasan/generic.c:186 [inline]
kasan_check_range+0x10f/0x1e0 mm/kasan/generic.c:200
__asan_memcpy+0x23/0x60 mm/kasan/shadow.c:105
report_descriptor_read+0xbb/0x100 drivers/hid/hid-core.c:2272
sysfs_kf_bin_read+0x156/0x210 fs/sysfs/file.c:102
kernfs_file_read_iter fs/kernfs/file.c:262 [inline]
kernfs_fop_read_iter+0x32b/0x610 fs/kernfs/file.c:291
new_sync_read fs/read_write.c:493 [inline]
vfs_read+0x82e/0xb40 fs/read_write.c:574
ksys_read+0x12a/0x250 fs/read_write.c:716
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x10b/0x7f0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fcdd3a5e407
Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007ffd1213c0d0 EFLAGS: 00000202 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007fcdd3970880 RCX: 00007fcdd3a5e407
RDX: 0000000000001000 RSI: 00007ffd1213c120 RDI: 0000000000000004
RBP: 0000558f17e1d2c0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000558f17e1c4c0
R13: 00007ffd1213c120 R14: 0000000000000004 R15: 0000558ee8aae4d8
</TASK>
Allocated by task 2921:
kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
kasan_save_track+0x14/0x30 mm/kasan/common.c:78
poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
__kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:415
kasan_kmalloc include/linux/kasan.h:263 [inline]
__do_kmalloc_node mm/slub.c:5334 [inline]
__kmalloc_node_track_caller_noprof+0x318/0x7d0 mm/slub.c:5471
kmemdup_noprof+0x29/0x60 mm/util.c:138
kmemdup_noprof include/linux/fortify-string.h:715 [inline]
hid_open_report+0x214/0x810 drivers/hid/hid-core.c:1376
hid_parse include/linux/hid.h:1206 [inline]
lg_probe+0x246/0x7e0 drivers/hid/hid-lg.c:783
__hid_device_probe drivers/hid/hid-core.c:2829 [inline]
hid_device_probe+0x50e/0x800 drivers/hid/hid-core.c:2866
call_driver_probe drivers/base/dd.c:628 [inline]
really_probe+0x241/0xa60 drivers/base/dd.c:706
__driver_probe_device+0x20e/0x450 drivers/base/dd.c:868
driver_probe_device+0x4a/0x140 drivers/base/dd.c:898
__device_attach_driver+0x1df/0x320 drivers/base/dd.c:1026
bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500
__device_attach+0x1e4/0x4d0 drivers/base/dd.c:1098
device_initial_probe+0xaf/0xd0 drivers/base/dd.c:1153
bus_probe_device+0x64/0x160 drivers/base/bus.c:620
device_add+0x121d/0x1970 drivers/base/core.c:3772
hid_add_device+0x2bf/0x440 drivers/hid/hid-core.c:3010
usbhid_probe+0xa64/0x10b0 drivers/hid/usbhid/hid-core.c:1452
usb_probe_interface+0x386/0x9b0 drivers/usb/core/driver.c:399
call_driver_probe drivers/base/dd.c:628 [inline]
really_probe+0x241/0xa60 drivers/base/dd.c:706
__driver_probe_device+0x20e/0x450 drivers/base/dd.c:868
driver_probe_device+0x4a/0x140 drivers/base/dd.c:898
__device_attach_driver+0x1df/0x320 drivers/base/dd.c:1026
bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500
__device_attach+0x1e4/0x4d0 drivers/base/dd.c:1098
device_initial_probe+0xaf/0xd0 drivers/base/dd.c:1153
bus_probe_device+0x64/0x160 drivers/base/bus.c:620
device_add+0x121d/0x1970 drivers/base/core.c:3772
usb_set_configuration+0xd97/0x1c60 drivers/usb/core/message.c:2268
usb_generic_driver_probe+0xa1/0xe0 drivers/usb/core/generic.c:250
usb_probe_device+0xef/0x400 drivers/usb/core/driver.c:293
call_driver_probe drivers/base/dd.c:628 [inline]
really_probe+0x241/0xa60 drivers/base/dd.c:706
__driver_probe_device+0x20e/0x450 drivers/base/dd.c:868
driver_probe_device+0x4a/0x140 drivers/base/dd.c:898
__device_attach_driver+0x1df/0x320 drivers/base/dd.c:1026
bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500
__device_attach+0x1e4/0x4d0 drivers/base/dd.c:1098
device_initial_probe+0xaf/0xd0 drivers/base/dd.c:1153
bus_probe_device+0x64/0x160 drivers/base/bus.c:620
device_add+0x121d/0x1970 drivers/base/core.c:3772
usb_new_device.part.0+0xcc2/0x1686 drivers/usb/core/hub.c:2708
usb_new_device drivers/usb/core/hub.c:5833 [inline]
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.cold+0x51a/0xe9d drivers/usb/core/hub.c:5966
process_one_work+0xa23/0x1940 kernel/workqueue.c:3322
process_scheduled_works kernel/workqueue.c:3405 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3486
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x69a/0xc80 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 ffff888120aa1480
which belongs to the cache kmalloc-32 of size 32
The buggy address is located 0 bytes inside of
freed 32-byte region [ffff888120aa1480, ffff888120aa14a0)
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x120aa1
flags: 0x200000000000000(node=0|zone=2)
page_type: f5(slab)
raw: 0200000000000000 ffff888100041780 dead000000000100 dead000000000122
raw: 0000000000000000 0000000800400040 00000000f5000000 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0xd2800(GFP_NOWAIT|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 4145, tgid 4145 (modprobe), ts 107921942180, free_ts 107809260171
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1859
prep_new_page mm/page_alloc.c:1867 [inline]
get_page_from_freelist+0xf25/0x3400 mm/page_alloc.c:3946
__alloc_frozen_pages_noprof+0x28f/0x2b90 mm/page_alloc.c:5304
alloc_slab_page mm/slub.c:3266 [inline]
allocate_slab mm/slub.c:3380 [inline]
new_slab+0xa2/0x670 mm/slub.c:3426
refill_objects+0xe3/0x410 mm/slub.c:7310
refill_sheaf mm/slub.c:2804 [inline]
__pcs_replace_empty_main+0x376/0x680 mm/slub.c:4675
alloc_from_pcs mm/slub.c:4773 [inline]
slab_alloc_node mm/slub.c:4905 [inline]
__kmalloc_cache_noprof+0x50e/0x670 mm/slub.c:5485
_kmalloc_noprof include/linux/slab.h:988 [inline]
slab_free_hook mm/slub.c:2629 [inline]
slab_free mm/slub.c:6377 [inline]
kmem_cache_free+0x3f3/0x650 mm/slub.c:6504
file_free fs/file_table.c:104 [inline]
__fput+0x68d/0xb50 fs/file_table.c:525
task_work_run+0x150/0x240 kernel/task_work.c:233
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x8d2/0x2a50 kernel/exit.c:1009
do_group_exit+0xd5/0x2a0 kernel/exit.c:1152
__do_sys_exit_group kernel/exit.c:1163 [inline]
__se_sys_exit_group kernel/exit.c:1161 [inline]
__x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1161
x64_sys_call+0x102c/0x1530 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x10b/0x7f0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 14 tgid 14 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
__free_pages_prepare mm/page_alloc.c:1406 [inline]
__free_frozen_pages+0x716/0xf50 mm/page_alloc.c:2950
rcu_do_batch kernel/rcu/tree.c:2645 [inline]
rcu_core+0x5a2/0x10d0 kernel/rcu/tree.c:2897
handle_softirqs+0x1dd/0x990 kernel/softirq.c:622
run_ksoftirqd kernel/softirq.c:1076 [inline]
run_ksoftirqd+0x38/0x60 kernel/softirq.c:1068
smpboot_thread_fn+0x3d3/0xaa0 kernel/smpboot.c:160
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x69a/0xc80 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:
ffff888120aa1380: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc
ffff888120aa1400: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc
>ffff888120aa1480: fb fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc
^
ffff888120aa1500: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc
ffff888120aa1580: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc
==================================================================
---
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.
prev parent reply other threads:[~2026-08-16 3:03 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-05-24 10:05 [syzbot] [input?] [usb?] KASAN: slab-use-after-free Read in report_descriptor_read syzbot
2026-08-16 3:03 ` syzbot [this message]
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