From: Marc Kleine-Budde <mkl@pengutronix.de>
To: netdev@vger.kernel.org
Cc: davem@davemloft.net, kuba@kernel.org, linux-can@vger.kernel.org,
kernel@pengutronix.de, Norbert Slusarek <nslusarek@gmx.net>,
linux-stable <stable@vger.kernel.org>,
Oliver Hartkopp <socketcan@hartkopp.net>,
Marc Kleine-Budde <mkl@pengutronix.de>
Subject: [net 3/4] can: bcm: fix infoleak in struct bcm_msg_head
Date: Wed, 16 Jun 2021 13:01:51 +0200 [thread overview]
Message-ID: <20210616110152.2456765-4-mkl@pengutronix.de> (raw)
In-Reply-To: <20210616110152.2456765-1-mkl@pengutronix.de>
From: Norbert Slusarek <nslusarek@gmx.net>
On 64-bit systems, struct bcm_msg_head has an added padding of 4 bytes between
struct members count and ival1. Even though all struct members are initialized,
the 4-byte hole will contain data from the kernel stack. This patch zeroes out
struct bcm_msg_head before usage, preventing infoleaks to userspace.
Fixes: ffd980f976e7 ("[CAN]: Add broadcast manager (bcm) protocol")
Link: https://lore.kernel.org/r/trinity-7c1b2e82-e34f-4885-8060-2cd7a13769ce-1623532166177@3c-app-gmx-bs52
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Norbert Slusarek <nslusarek@gmx.net>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
net/can/bcm.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/net/can/bcm.c b/net/can/bcm.c
index f00176b2a6c3..f3e4d9528fa3 100644
--- a/net/can/bcm.c
+++ b/net/can/bcm.c
@@ -406,6 +406,7 @@ static enum hrtimer_restart bcm_tx_timeout_handler(struct hrtimer *hrtimer)
if (!op->count && (op->flags & TX_COUNTEVT)) {
/* create notification to user */
+ memset(&msg_head, 0, sizeof(msg_head));
msg_head.opcode = TX_EXPIRED;
msg_head.flags = op->flags;
msg_head.count = op->count;
@@ -443,6 +444,7 @@ static void bcm_rx_changed(struct bcm_op *op, struct canfd_frame *data)
/* this element is not throttled anymore */
data->flags &= (BCM_CAN_FLAGS_MASK|RX_RECV);
+ memset(&head, 0, sizeof(head));
head.opcode = RX_CHANGED;
head.flags = op->flags;
head.count = op->count;
@@ -564,6 +566,7 @@ static enum hrtimer_restart bcm_rx_timeout_handler(struct hrtimer *hrtimer)
}
/* create notification to user */
+ memset(&msg_head, 0, sizeof(msg_head));
msg_head.opcode = RX_TIMEOUT;
msg_head.flags = op->flags;
msg_head.count = op->count;
--
2.30.2
next prev parent reply other threads:[~2021-06-16 11:02 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-16 11:01 pull-request: can 2021-06-16 Marc Kleine-Budde
2021-06-16 11:01 ` [net 1/4] can: j1939: fix Use-after-Free, hold skb ref while in use Marc Kleine-Budde
2021-06-16 11:01 ` [net 2/4] can: bcm/raw/isotp: use per module netdevice notifier Marc Kleine-Budde
2021-06-16 11:01 ` Marc Kleine-Budde [this message]
2021-06-16 11:01 ` [net 4/4] can: mcba_usb: fix memory leak in mcba_usb Marc Kleine-Budde
2021-06-16 19:50 ` pull-request: can 2021-06-16 patchwork-bot+netdevbpf
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