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authorNorbert Slusarek <nslusarek@gmx.net>2021-06-12 23:18:54 +0300
committerMarc Kleine-Budde <mkl@pengutronix.de>2021-06-16 13:52:18 +0300
commit5e87ddbe3942e27e939bdc02deb8579b0cbd8ecc (patch)
tree65e6bfa6d5758582377e6be43fb1d799372f6571 /net/can
parent8d0caedb759683041d9db82069937525999ada53 (diff)
downloadlinux-5e87ddbe3942e27e939bdc02deb8579b0cbd8ecc.tar.xz
can: bcm: fix infoleak in struct bcm_msg_head
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>
Diffstat (limited to 'net/can')
-rw-r--r--net/can/bcm.c3
1 files changed, 3 insertions, 0 deletions
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;