[syzbot] [usb?] UBSAN: array-index-out-of-bounds in usbhid_parse

[syzbot] [usb?] UBSAN: array-index-out-of-bounds in usbhid_parse

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    ad7f1baed071 Merge tag 'acpi-6.6-rc6' of git://git.kernel...
git tree:       upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=1056d5c5680000
kernel config:  https://syzkaller.appspot.com/x/.config?x=32d0b9b42ceb8b10
dashboard link: https://syzkaller.appspot.com/bug?extid=c52569baf0c843f35495
compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1081f1e5680000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=16c7bc4d680000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/e3074ad3ff92/disk-ad7f1bae.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/94b298a1e285/vmlinux-ad7f1bae.xz
kernel image: https://storage.googleapis.com/syzbot-assets/1ad5cd9c2a48/bzImage-ad7f1bae.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+c52569baf0c843f35495@syzkaller.appspotmail.com

usb 1-1: string descriptor 0 read error: -22
usb 1-1: New USB device found, idVendor=080e, idProduct=4eb9, bcdDevice=d7.f6
usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
================================================================================
UBSAN: array-index-out-of-bounds in drivers/hid/usbhid/hid-core.c:1024:18
index 1 is out of range for type 'hid_class_descriptor [1]'
CPU: 0 PID: 9 Comm: kworker/0:1 Not tainted 6.6.0-rc5-syzkaller-00227-gad7f1baed071 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023
Workqueue: usb_hub_wq hub_event
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x125/0x1b0 lib/dump_stack.c:106
 ubsan_epilogue lib/ubsan.c:217 [inline]
 __ubsan_handle_out_of_bounds+0x111/0x150 lib/ubsan.c:348
 usbhid_parse+0x94a/0xa20 drivers/hid/usbhid/hid-core.c:1024
 hid_add_device+0x189/0xa60 drivers/hid/hid-core.c:2783
 usbhid_probe+0xd0a/0x1360 drivers/hid/usbhid/hid-core.c:1429
 usb_probe_interface+0x307/0x930 drivers/usb/core/driver.c:396
 call_driver_probe drivers/base/dd.c:579 [inline]
 really_probe+0x234/0xc90 drivers/base/dd.c:658
 __driver_probe_device+0x1de/0x4b0 drivers/base/dd.c:800
 driver_probe_device+0x4c/0x1a0 drivers/base/dd.c:830
 __device_attach_driver+0x1d4/0x300 drivers/base/dd.c:958
 bus_for_each_drv+0x157/0x1d0 drivers/base/bus.c:457
 __device_attach+0x1e8/0x4b0 drivers/base/dd.c:1030
 bus_probe_device+0x17c/0x1c0 drivers/base/bus.c:532
 device_add+0x117e/0x1aa0 drivers/base/core.c:3624
 usb_set_configuration+0x10cb/0x1c40 drivers/usb/core/message.c:2207
 usb_generic_driver_probe+0xca/0x130 drivers/usb/core/generic.c:238
 usb_probe_device+0xda/0x2c0 drivers/usb/core/driver.c:293
 call_driver_probe drivers/base/dd.c:579 [inline]
 really_probe+0x234/0xc90 drivers/base/dd.c:658
 __driver_probe_device+0x1de/0x4b0 drivers/base/dd.c:800
 driver_probe_device+0x4c/0x1a0 drivers/base/dd.c:830
 __device_attach_driver+0x1d4/0x300 drivers/base/dd.c:958
 bus_for_each_drv+0x157/0x1d0 drivers/base/bus.c:457
 __device_attach+0x1e8/0x4b0 drivers/base/dd.c:1030
 bus_probe_device+0x17c/0x1c0 drivers/base/bus.c:532
 device_add+0x117e/0x1aa0 drivers/base/core.c:3624
 usb_new_device+0xd80/0x1960 drivers/usb/core/hub.c:2589
 hub_port_connect drivers/usb/core/hub.c:5440 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5580 [inline]
 port_event drivers/usb/core/hub.c:5740 [inline]
 hub_event+0x2daf/0x4e00 drivers/usb/core/hub.c:5822
 process_one_work+0x884/0x15c0 kernel/workqueue.c:2630
 process_scheduled_works kernel/workqueue.c:2703 [inline]
 worker_thread+0x8b9/0x1290 kernel/workqueue.c:2784
 kthread+0x33c/0x440 kernel/kthread.c:388
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304
 </TASK>
================================================================================


---
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Re: [syzbot] [PATCH] usbhid: fix array-index-out-of-bounds in usbhid_parse UBSAN warning

[Kees Cook]

Hi,

What's happened to getting a new version of this patch? This flaw is
still reachable in -next from what I can see?

Thanks,

-Kees

On Sat, Dec 23, 2023 at 11:59:51AM -0800, syzbot wrote:
> For archival purposes, forwarding an incoming command email to
> linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com.
> 
> ***
> 
> Subject: [PATCH] usbhid: fix array-index-out-of-bounds in usbhid_parse UBSAN warning
> Author: tintinm2017@gmail.com
> 
> #syz test: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> 
> Look at the bug https://syzkaller.appspot.com/bug?extid=c52569baf0c843f35495 reported by syzbot. Tested a patch through syzbot, which gives an error. 
> Requesting help from the maintainers to understand what is really going wrong in the code. 
> 
> Based on my understanding, I believe the value of the number of descriptors is calculated incorrectly before the for loop.
> 
> Signed-off-by: Attreyee Mukherjee <tintinm2017@gmail.com>
> ---
>  drivers/hid/usbhid/hid-core.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/hid/usbhid/hid-core.c b/drivers/hid/usbhid/hid-core.c
> index a90ed2ceae84..582ddbef448f 100644
> --- a/drivers/hid/usbhid/hid-core.c
> +++ b/drivers/hid/usbhid/hid-core.c
> @@ -1021,6 +1021,8 @@ static int usbhid_parse(struct hid_device *hid)
>  	       (hdesc->bLength - offset) / sizeof(struct hid_class_descriptor));
>  
>  	for (n = 0; n < num_descriptors; n++)
> +		if (n >= ARRAY_SIZE(hdesc->desc))
> +			break;
>  		if (hdesc->desc[n].bDescriptorType == HID_DT_REPORT)
>  			rsize = le16_to_cpu(hdesc->desc[n].wDescriptorLength);
>  
> -- 
> 2.34.1
> 

-- 
Kees Cook