diff mbox series

[Linux-kernel-mentees,v2] usbhid: Fix slab-out-of-bounds write in hiddev_ioctl_usage()

Message ID 20200720195209.4365-1-yepeilin.cs@gmail.com (mailing list archive)
State Superseded
Delegated to: Jiri Kosina
Headers show
Series [Linux-kernel-mentees,v2] usbhid: Fix slab-out-of-bounds write in hiddev_ioctl_usage() | expand

Commit Message

Peilin Ye July 20, 2020, 7:52 p.m. UTC
`uref->usage_index` is not always being properly checked, causing
hiddev_ioctl_usage() to go out of bounds under some cases. Fix it.

Reported-by: syzbot+34ee1b45d88571c2fa8b@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?id=f2aebe90b8c56806b050a20b36f51ed6acabe802
Signed-off-by: Peilin Ye <yepeilin.cs@gmail.com>
---
Change in v2:
    - Add the same check for the `HIDIOCGUSAGE` case. (Suggested by
      Dan Carpenter <dan.carpenter@oracle.com>)

 drivers/hid/usbhid/hiddev.c | 4 ++++
 1 file changed, 4 insertions(+)

Comments

Dan Carpenter July 23, 2020, 2:51 p.m. UTC | #1
On Mon, Jul 20, 2020 at 03:52:09PM -0400, Peilin Ye wrote:
> `uref->usage_index` is not always being properly checked, causing
> hiddev_ioctl_usage() to go out of bounds under some cases. Fix it.
> 
> Reported-by: syzbot+34ee1b45d88571c2fa8b@syzkaller.appspotmail.com
> Link: https://syzkaller.appspot.com/bug?id=f2aebe90b8c56806b050a20b36f51ed6acabe802
> Signed-off-by: Peilin Ye <yepeilin.cs@gmail.com>
> ---
> Change in v2:
>     - Add the same check for the `HIDIOCGUSAGE` case. (Suggested by
>       Dan Carpenter <dan.carpenter@oracle.com>)

Looks good to me.  Thanks!

Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>

regards,
dan carpenter
diff mbox series

Patch

diff --git a/drivers/hid/usbhid/hiddev.c b/drivers/hid/usbhid/hiddev.c
index 4140dea693e9..4f97e6c12059 100644
--- a/drivers/hid/usbhid/hiddev.c
+++ b/drivers/hid/usbhid/hiddev.c
@@ -519,12 +519,16 @@  static noinline int hiddev_ioctl_usage(struct hiddev *hiddev, unsigned int cmd,
 
 		switch (cmd) {
 		case HIDIOCGUSAGE:
+			if (uref->usage_index >= field->report_count)
+				goto inval;
 			uref->value = field->value[uref->usage_index];
 			if (copy_to_user(user_arg, uref, sizeof(*uref)))
 				goto fault;
 			goto goodreturn;
 
 		case HIDIOCSUSAGE:
+			if (uref->usage_index >= field->report_count)
+				goto inval;
 			field->value[uref->usage_index] = uref->value;
 			goto goodreturn;