* Re: [syzbot] [input?] [usb?] KASAN: slab-use-after-free Read in report_descriptor_read
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
2026-10-09 8:52 ` Forwarded: [PATCH] HID: core: serialize report_descriptor_read() against probe and remove syzbot
` (3 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: syzbot @ 2026-08-16 3:03 UTC (permalink / raw)
To: bentiss, jikos, linux-input, linux-kernel, linux-usb, syzkaller-bugs
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.
^ permalink raw reply [flat|nested] 6+ messages in thread* Forwarded: [PATCH] HID: core: serialize report_descriptor_read() against probe and remove
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
@ 2026-10-09 8:52 ` syzbot
2026-10-09 10:28 ` syzbot
` (2 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: syzbot @ 2026-10-09 8:52 UTC (permalink / raw)
To: linux-kernel, syzkaller-bugs
For archival purposes, forwarding an incoming command email to
linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com.
***
Subject: [PATCH] HID: core: serialize report_descriptor_read() against probe and remove
Author: krishgulati7@gmail.com
#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
Since commit 54f32fd5dff9 ("HID: Make report_descriptor available for
all devices"), the "report_descriptor" sysfs attribute is part of the
device's attribute group, so it exists from device_add() until
device_del(). It reads hdev->rdesc, but that buffer only lives from
hid_open_report() until hid_close_report(), that is, for the duration
of a driver binding. For a driver with a report_fixup() callback,
rdesc is a private copy that hid_close_report() frees, so a read that
races with the driver being unbound accesses freed memory. syzbot
reports this as:
BUG: KASAN: slab-use-after-free in report_descriptor_read+0xb5/0x100
Read of size 24 at addr ffff888078d61f00 by task fido_id/7281
...
Allocated by task 10:
kmemdup_noprof+0x2b/0x70
hid_open_report+0x1fa/0xf00
lg_probe+0x29c/0x890
hid_device_probe+0x46a/0x870
...
Because hid_close_report() also clears rdesc and rsize, the same missing
serialization can make the reader see a NULL rdesc with a non-zero
rsize.
Hold the device lock in report_descriptor_read(). The driver core
already holds it across probe and remove, so a read can no longer
overlap with them.
Reported-by: syzbot+bc537ca7a0efe33988eb@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=bc537ca7a0efe33988eb
Fixes: 54f32fd5dff9 ("HID: Make report_descriptor available for all devices")
Signed-off-by: Krish Gulati <krishgulati7@gmail.com>
---
drivers/hid/hid-core.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index a3ff0514f9cd..824557a02544 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -2270,6 +2270,8 @@ report_descriptor_read(struct file *filp, struct kobject *kobj,
struct device *dev = kobj_to_dev(kobj);
struct hid_device *hdev = to_hid_device(dev);
+ guard(device)(dev);
+
if (off >= hdev->rsize)
return 0;
--
2.56.0
^ permalink raw reply [flat|nested] 6+ messages in thread* Forwarded: [PATCH] HID: core: serialize report_descriptor_read() against probe and remove
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
2026-10-09 8:52 ` Forwarded: [PATCH] HID: core: serialize report_descriptor_read() against probe and remove syzbot
@ 2026-10-09 10:28 ` syzbot
2026-10-15 2:08 ` [syzbot] [input?] [usb?] KASAN: slab-use-after-free Read in report_descriptor_read syzbot
2026-10-16 10:54 ` Forwarded: [PATCH] HID: core: serialize report_descriptor_read() against probe and remove syzbot
4 siblings, 0 replies; 6+ messages in thread
From: syzbot @ 2026-10-09 10:28 UTC (permalink / raw)
To: linux-kernel, syzkaller-bugs
For archival purposes, forwarding an incoming command email to
linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com.
***
Subject: [PATCH] HID: core: serialize report_descriptor_read() against probe and remove
Author: krishgulati7@gmail.com
#syz test: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git bdab5605259b
Since commit 54f32fd5dff9 ("HID: Make report_descriptor available for
all devices"), the "report_descriptor" sysfs attribute is part of the
device's attribute group, so it exists from device_add() until
device_del(). It reads hdev->rdesc, but that buffer only lives from
hid_open_report() until hid_close_report(), that is, for the duration
of a driver binding. For a driver with a report_fixup() callback,
rdesc is a private copy that hid_close_report() frees, so a read that
races with the driver being unbound accesses freed memory. syzbot
reports this as:
BUG: KASAN: slab-use-after-free in report_descriptor_read+0xb5/0x100
Read of size 24 at addr ffff888078d61f00 by task fido_id/7281
...
Allocated by task 10:
kmemdup_noprof+0x2b/0x70
hid_open_report+0x1fa/0xf00
lg_probe+0x29c/0x890
hid_device_probe+0x46a/0x870
...
Because hid_close_report() also clears rdesc and rsize, the same missing
serialization can make the reader see a NULL rdesc with a non-zero
rsize.
Hold the device lock in report_descriptor_read(). The driver core
already holds it across probe and remove, so a read can no longer
overlap with them.
Reported-by: syzbot+bc537ca7a0efe33988eb@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=bc537ca7a0efe33988eb
Fixes: 54f32fd5dff9 ("HID: Make report_descriptor available for all devices")
Signed-off-by: Krish Gulati <krishgulati7@gmail.com>
---
drivers/hid/hid-core.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index a3ff0514f9cd..824557a02544 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -2270,6 +2270,8 @@ report_descriptor_read(struct file *filp, struct kobject *kobj,
struct device *dev = kobj_to_dev(kobj);
struct hid_device *hdev = to_hid_device(dev);
+ guard(device)(dev);
+
if (off >= hdev->rsize)
return 0;
--
2.56.0
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [syzbot] [input?] [usb?] KASAN: slab-use-after-free Read in report_descriptor_read
2025-05-24 10:05 [syzbot] [input?] [usb?] KASAN: slab-use-after-free Read in report_descriptor_read syzbot
` (2 preceding siblings ...)
2026-10-09 10:28 ` syzbot
@ 2026-10-15 2:08 ` syzbot
2026-10-16 10:54 ` Forwarded: [PATCH] HID: core: serialize report_descriptor_read() against probe and remove syzbot
4 siblings, 0 replies; 6+ messages in thread
From: syzbot @ 2026-10-15 2:08 UTC (permalink / raw)
To: bentiss, jikos, krishgulati7, linux-input, linux-kernel,
linux-usb, luto, stable, syzkaller-bugs
syzbot has found a reproducer for the following issue on:
HEAD commit: d419d682257d Add linux-next specific files for 20261014
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=15f308a5580000
kernel config: https://syzkaller.appspot.com/x/.config?x=c9a67c2e7f805a9d
dashboard link: https://syzkaller.appspot.com/bug?extid=bc537ca7a0efe33988eb
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=13f7329c580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15dcce8e580000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/4bce8ec075a1/disk-d419d682.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/757ea19f6a55/vmlinux-d419d682.xz
kernel image: https://storage.googleapis.com/syzbot-assets/de4428185ddb/bzImage-d419d682.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+0xb5/0x100 drivers/hid/hid-core.c:2279
Read of size 24 at addr ffff88802c2b9e80 by task fido_id/6017
CPU: 0 UID: 0 PID: 6017 Comm: fido_id Not tainted syzkaller #0 PREEMPT(full)
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
check_region_inline mm/kasan/generic.c:-1 [inline]
kasan_check_range+0x264/0x2c0 mm/kasan/generic.c:200
__asan_memcpy+0x29/0x70 mm/kasan/shadow.c:105
report_descriptor_read+0xb5/0x100 drivers/hid/hid-core.c:2279
kernfs_file_read_iter fs/kernfs/file.c:262 [inline]
kernfs_fop_read_iter+0x434/0x6a0 fs/kernfs/file.c:291
new_sync_read fs/read_write.c:493 [inline]
vfs_read+0x595/0xa80 fs/read_write.c:574
ksys_read+0x150/0x270 fs/read_write.c:716
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
RIP: 0033:0x7f840a7dd407
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:00007ffe134d2db0 EFLAGS: 00000202 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007f840a751880 RCX: 00007f840a7dd407
RDX: 0000000000001000 RSI: 00007ffe134d2e00 RDI: 0000000000000004
RBP: 000055f16ea9c730 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 000055f16ea9b930
R13: 00007ffe134d2e00 R14: 0000000000000004 R15: 000055f1306884d8
</TASK>
Allocated by task 5342:
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:409 [inline]
__kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:426
kasan_kmalloc include/linux/kasan.h:263 [inline]
__do_kmalloc_node mm/slub.c:5531 [inline]
__kmalloc_node_track_caller_noprof+0x4af/0x720 mm/slub.c:5662
kmemdup_noprof+0x2b/0x70 mm/util.c:138
kmemdup_noprof include/linux/fortify-string.h:713 [inline]
hid_open_report+0x1fa/0xf00 drivers/hid/hid-core.c:1382
hid_parse include/linux/hid.h:1208 [inline]
lg_probe+0x29c/0x890 drivers/hid/hid-lg.c:783
__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:503
__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:623
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+0x751/0xe00 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:503
__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:623
device_add+0x7d7/0xb80 drivers/base/core.c:3776
usb_set_configuration+0x1bb5/0x2260 drivers/usb/core/message.c:2274
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:503
__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:623
device_add+0x7d7/0xb80 drivers/base/core.c:3776
usb_new_device+0x9aa/0x1690 drivers/usb/core/hub.c:2713
hub_port_connect drivers/usb/core/hub.c:5585 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5725 [inline]
port_event drivers/usb/core/hub.c:5889 [inline]
hub_event+0x28e8/0x4d30 drivers/usb/core/hub.c:5971
process_one_work kernel/workqueue.c:3495 [inline]
process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3578
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3659
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
The buggy address belongs to the object at ffff88802c2b9e80
which belongs to the cache kmalloc-32 of size 32
The buggy address is located 0 bytes inside of
freed 32-byte region [ffff88802c2b9e80, ffff88802c2b9ea0)
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88802c2b9b40 pfn:0x2c2b9
flags: 0xfff00000000200(workingset|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000200 ffff88813ff26780 ffffea0001fd0550 ffffea0000ae0e90
raw: ffff88802c2b9b40 000000000040003c 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 0xd2cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, tgid 1 (swapper/0), ts 10415342596
set_page_owner include/linux/page_owner.h:33 [inline]
post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1854
prep_new_page mm/page_alloc.c:1862 [inline]
get_page_from_freelist+0x220f/0x2280 mm/page_alloc.c:3933
__alloc_frozen_pages_noprof+0x1fe/0x410 mm/page_alloc.c:5457
alloc_slab_page mm/slub.c:3384 [inline]
allocate_slab+0x7d/0x5e0 mm/slub.c:3499
new_slab mm/slub.c:3550 [inline]
refill_objects+0x2d5/0x350 mm/slub.c:7539
refill_sheaf mm/slub.c:2917 [inline]
__pcs_replace_empty_main+0x2c8/0x6c0 mm/slub.c:4811
alloc_from_pcs mm/slub.c:4887 [inline]
slab_alloc_node mm/slub.c:5021 [inline]
__do_kmalloc_node mm/slub.c:5530 [inline]
__kmalloc_noprof+0x476/0x710 mm/slub.c:5556
_kmalloc_noprof include/linux/slab.h:995 [inline]
_kzalloc_noprof include/linux/slab.h:1312 [inline]
kobject_get_path+0xc5/0x2f0 lib/kobject.c:161
kobject_uevent_env+0x29e/0x9e0 lib/kobject_uevent.c:548
really_probe+0x774/0xae0 drivers/base/dd.c:756
__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:503
__device_attach+0x2c4/0x450 drivers/base/dd.c:1098
device_initial_probe+0xa1/0xd0 drivers/base/dd.c:1153
page_owner free stack trace missing
Memory state around the buggy address:
ffff88802c2b9d80: fa fb fb fb fc fc fc fc 00 00 00 00 fc fc fc fc
ffff88802c2b9e00: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc
>ffff88802c2b9e80: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc
^
ffff88802c2b9f00: 00 00 00 07 fc fc fc fc fa fb fb fb fc fc fc fc
ffff88802c2b9f80: 00 00 00 00 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.
^ permalink raw reply [flat|nested] 6+ messages in thread* Forwarded: [PATCH] HID: core: serialize report_descriptor_read() against probe and remove
2025-05-24 10:05 [syzbot] [input?] [usb?] KASAN: slab-use-after-free Read in report_descriptor_read syzbot
` (3 preceding siblings ...)
2026-10-15 2:08 ` [syzbot] [input?] [usb?] KASAN: slab-use-after-free Read in report_descriptor_read syzbot
@ 2026-10-16 10:54 ` syzbot
4 siblings, 0 replies; 6+ messages in thread
From: syzbot @ 2026-10-16 10:54 UTC (permalink / raw)
To: linux-kernel, syzkaller-bugs
For archival purposes, forwarding an incoming command email to
linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com.
***
Subject: [PATCH] HID: core: serialize report_descriptor_read() against probe and remove
Author: krishgulati7@gmail.com
#syz test: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git next-20261014
Since commit 54f32fd5dff9 ("HID: Make report_descriptor available for
all devices"), the "report_descriptor" sysfs attribute is part of the
device's attribute group, so it exists from device_add() until
device_del(). It reads hdev->rdesc, but that buffer only lives from
hid_open_report() until hid_close_report(), that is, for the duration
of a driver binding. For a driver with a report_fixup() callback,
rdesc is a private copy that hid_close_report() frees, so a read that
races with the driver being unbound accesses freed memory. syzbot
reports this as:
BUG: KASAN: slab-use-after-free in report_descriptor_read+0xb5/0x100
Read of size 24 at addr ffff888078d61f00 by task fido_id/7281
...
Allocated by task 10:
kmemdup_noprof+0x2b/0x70
hid_open_report+0x1fa/0xf00
lg_probe+0x29c/0x890
hid_device_probe+0x46a/0x870
...
Because hid_close_report() also clears rdesc and rsize, the same missing
serialization can make the reader see a NULL rdesc with a non-zero
rsize.
Hold the device lock in report_descriptor_read(). The driver core
already holds it across probe and remove, so a read can no longer
overlap with them.
Reported-by: syzbot+bc537ca7a0efe33988eb@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=bc537ca7a0efe33988eb
Fixes: 54f32fd5dff9 ("HID: Make report_descriptor available for all devices")
Cc: stable@vger.kernel.org
Signed-off-by: Krish Gulati <krishgulati7@gmail.com>
---
drivers/hid/hid-core.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index a3ff0514f9cd..824557a02544 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -2270,6 +2270,8 @@ report_descriptor_read(struct file *filp, struct kobject *kobj,
struct device *dev = kobj_to_dev(kobj);
struct hid_device *hdev = to_hid_device(dev);
+ guard(device)(dev);
+
if (off >= hdev->rsize)
return 0;
--
2.56.0
^ permalink raw reply [flat|nested] 6+ messages in thread