From: Peilin Ye <yepeilin.cs@gmail.com>
To: Jiri Kosina <jikos@kernel.org>,
Benjamin Tissoires <benjamin.tissoires@redhat.com>
Cc: Peilin Ye <yepeilin.cs@gmail.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
syzkaller-bugs@googlegroups.com,
linux-kernel-mentees@lists.linuxfoundation.org,
linux-usb@vger.kernel.org, linux-input@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: [Linux-kernel-mentees] [PATCH v1] usbhid: Fix slab-out-of-bounds write in hiddev_ioctl_usage()
Date: Sat, 18 Jul 2020 19:12:18 -0400 [thread overview]
Message-ID: <20200718231218.170730-1-yepeilin.cs@gmail.com> (raw)
`uref->usage_index` is not always being properly checked, causing
hiddev_ioctl_usage() to go out of bounds under some cases. Fix it.
This patch fixes the following syzbot bug:
https://syzkaller.appspot.com/bug?id=f2aebe90b8c56806b050a20b36f51ed6acabe802
Reported-by: syzbot+34ee1b45d88571c2fa8b@syzkaller.appspotmail.com
Signed-off-by: Peilin Ye <yepeilin.cs@gmail.com>
---
This patch fixes the bug, but in an ugly way. Checks on `uref` are already
being done in this code:
if (cmd == HIDIOCGCOLLECTIONINDEX) {
if (uref->usage_index >= field->maxusage)
goto inval;
uref->usage_index =
array_index_nospec(uref->usage_index,
field->maxusage);
} else if (uref->usage_index >= field->report_count)
goto inval;
However it did not catch this bug since it's in an `else` bracket. Should
we move the above code out of the bracket? Would like to hear your opinion.
Thank you!
drivers/hid/usbhid/hiddev.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/hid/usbhid/hiddev.c b/drivers/hid/usbhid/hiddev.c
index 4140dea693e9..c63d07caacef 100644
--- a/drivers/hid/usbhid/hiddev.c
+++ b/drivers/hid/usbhid/hiddev.c
@@ -525,6 +525,8 @@ static noinline int hiddev_ioctl_usage(struct hiddev *hiddev, unsigned int cmd,
goto goodreturn;
case HIDIOCSUSAGE:
+ if (uref->usage_index >= field->report_count)
+ goto inval;
field->value[uref->usage_index] = uref->value;
goto goodreturn;
--
2.25.1
next reply other threads:[~2020-07-18 23:14 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-18 23:12 Peilin Ye [this message]
2020-07-20 11:54 ` [Linux-kernel-mentees] [PATCH v1] usbhid: Fix slab-out-of-bounds write in hiddev_ioctl_usage() Dan Carpenter
2020-07-20 12:12 ` Dan Carpenter
2020-07-20 19:05 ` Peilin Ye
2020-07-20 19:16 ` Peilin Ye
2020-07-21 7:16 ` Dan Carpenter
2020-07-21 8:27 ` Greg Kroah-Hartman
2020-07-21 8:39 ` Dan Carpenter
2020-07-21 8:39 ` Peilin Ye
2020-07-20 19:52 ` [Linux-kernel-mentees] [PATCH v2] " Peilin Ye
2020-07-23 14:51 ` Dan Carpenter
2020-07-29 11:37 ` [Linux-kernel-mentees] [PATCH v2 RESEND] " Peilin Ye
2020-07-29 14:35 ` Dan Carpenter
2020-08-17 10:21 ` Jiri Kosina
2020-08-18 10:00 ` Peilin Ye
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=20200718231218.170730-1-yepeilin.cs@gmail.com \
--to=yepeilin.cs@gmail.com \
--cc=benjamin.tissoires@redhat.com \
--cc=gregkh@linuxfoundation.org \
--cc=jikos@kernel.org \
--cc=linux-input@vger.kernel.org \
--cc=linux-kernel-mentees@lists.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).