linux-kernel - [PATCH 4.19 30/58] can: peak_usb: fix use after free bugs

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Mon, 25 Jan 2021 19:39:31 +0100
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org,
        Vincent Mailhol <mailhol.vincent@...adoo.fr>,
        Marc Kleine-Budde <mkl@...gutronix.de>,
        Sasha Levin <sashal@...nel.org>
Subject: [PATCH 4.19 30/58] can: peak_usb: fix use after free bugs

From: Vincent Mailhol <mailhol.vincent@...adoo.fr>

[ Upstream commit 50aca891d7a554db0901b245167cd653d73aaa71 ]

After calling peak_usb_netif_rx_ni(skb), dereferencing skb is unsafe.
Especially, the can_frame cf which aliases skb memory is accessed
after the peak_usb_netif_rx_ni().

Reordering the lines solves the issue.

Fixes: 0a25e1f4f185 ("can: peak_usb: add support for PEAK new CANFD USB adapters")
Link: https://lore.kernel.org/r/20210120114137.200019-4-mailhol.vincent@wanadoo.fr
Signed-off-by: Vincent Mailhol <mailhol.vincent@...adoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@...gutronix.de>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/net/can/usb/peak_usb/pcan_usb_fd.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/net/can/usb/peak_usb/pcan_usb_fd.c b/drivers/net/can/usb/peak_usb/pcan_usb_fd.c
index 19600d35aac55..40ac37fe9dcde 100644
--- a/drivers/net/can/usb/peak_usb/pcan_usb_fd.c
+++ b/drivers/net/can/usb/peak_usb/pcan_usb_fd.c
@@ -520,11 +520,11 @@ static int pcan_usb_fd_decode_canmsg(struct pcan_usb_fd_if *usb_if,
 	else
 		memcpy(cfd->data, rm->d, cfd->len);
 
-	peak_usb_netif_rx(skb, &usb_if->time_ref, le32_to_cpu(rm->ts_low));
-
 	netdev->stats.rx_packets++;
 	netdev->stats.rx_bytes += cfd->len;
 
+	peak_usb_netif_rx(skb, &usb_if->time_ref, le32_to_cpu(rm->ts_low));
+
 	return 0;
 }
 
@@ -586,11 +586,11 @@ static int pcan_usb_fd_decode_status(struct pcan_usb_fd_if *usb_if,
 	if (!skb)
 		return -ENOMEM;
 
-	peak_usb_netif_rx(skb, &usb_if->time_ref, le32_to_cpu(sm->ts_low));
-
 	netdev->stats.rx_packets++;
 	netdev->stats.rx_bytes += cf->can_dlc;
 
+	peak_usb_netif_rx(skb, &usb_if->time_ref, le32_to_cpu(sm->ts_low));
+
 	return 0;
 }
 
-- 
2.27.0