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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Pavel Skripkin <paskripkin@gmail.com>,
        Jiri Kosina <jkosina@suse.cz>, Sasha Levin <sashal@kernel.org>,
        syzbot+35eebd505e97d315d01c@syzkaller.appspotmail.com
Subject: [PATCH 5.15 004/110] HID: hid-thrustmaster: fix OOB read in thrustmaster_interrupts
Date:   Mon, 14 Mar 2022 12:53:06 +0100
Message-Id: <20220314112743.154783242@linuxfoundation.org>
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From: Pavel Skripkin <paskripkin@gmail.com>

[ Upstream commit fc3ef2e3297b3c0e2006b5d7b3d66965e3392036 ]

Syzbot reported an slab-out-of-bounds Read in thrustmaster_probe() bug.
The root case is in missing validation check of actual number of endpoints.

Code should not blindly access usb_host_interface::endpoint array, since
it may contain less endpoints than code expects.

Fix it by adding missing validaion check and print an error if
number of endpoints do not match expected number

Fixes: c49c33637802 ("HID: support for initialization of some Thrustmaster wheels")
Reported-and-tested-by: syzbot+35eebd505e97d315d01c@syzkaller.appspotmail.com
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/hid/hid-thrustmaster.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/hid/hid-thrustmaster.c b/drivers/hid/hid-thrustmaster.c
index 0c92b7f9b8b8..afdd778a10f0 100644
--- a/drivers/hid/hid-thrustmaster.c
+++ b/drivers/hid/hid-thrustmaster.c
@@ -158,6 +158,12 @@ static void thrustmaster_interrupts(struct hid_device *hdev)
 		return;
 	}
 
+	if (usbif->cur_altsetting->desc.bNumEndpoints < 2) {
+		kfree(send_buf);
+		hid_err(hdev, "Wrong number of endpoints?\n");
+		return;
+	}
+
 	ep = &usbif->cur_altsetting->endpoint[1];
 	b_ep = ep->desc.bEndpointAddress;
 
-- 
2.34.1