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authorOliver Hartkopp <socketcan@hartkopp.net>2019-01-13 19:31:43 +0100
committerMarc Kleine-Budde <mkl@pengutronix.de>2019-01-22 11:33:46 +0100
commit93171ba6f1deffd82f381d36cb13177872d023f6 (patch)
tree5f561038080d2b31941a39fec548e60edfc28e4c /net/can
parent7b12c8189a3dc50638e7d53714c88007268d47ef (diff)
downloadlinux-stericsson-93171ba6f1deffd82f381d36cb13177872d023f6.tar.gz
can: bcm: check timer values before ktime conversion
Kyungtae Kim detected a potential integer overflow in bcm_[rx|tx]_setup() when the conversion into ktime multiplies the given value with NSEC_PER_USEC (1000). Reference: https://marc.info/?l=linux-can&m=154732118819828&w=2 Add a check for the given tv_usec, so that the value stays below one second. Additionally limit the tv_sec value to a reasonable value for CAN related use-cases of 400 days and ensure all values to be positive. Reported-by: Kyungtae Kim <kt0755@gmail.com> Tested-by: Oliver Hartkopp <socketcan@hartkopp.net> Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net> Cc: linux-stable <stable@vger.kernel.org> # >= 2.6.26 Tested-by: Kyungtae Kim <kt0755@gmail.com> Acked-by: Andre Naujoks <nautsch2@gmail.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Diffstat (limited to 'net/can')
-rw-r--r--net/can/bcm.c27
1 files changed, 27 insertions, 0 deletions
diff --git a/net/can/bcm.c b/net/can/bcm.c
index 0af8f0db892a..79bb8afa9c0c 100644
--- a/net/can/bcm.c
+++ b/net/can/bcm.c
@@ -67,6 +67,9 @@
*/
#define MAX_NFRAMES 256
+/* limit timers to 400 days for sending/timeouts */
+#define BCM_TIMER_SEC_MAX (400 * 24 * 60 * 60)
+
/* use of last_frames[index].flags */
#define RX_RECV 0x40 /* received data for this element */
#define RX_THR 0x80 /* element not been sent due to throttle feature */
@@ -140,6 +143,22 @@ static inline ktime_t bcm_timeval_to_ktime(struct bcm_timeval tv)
return ktime_set(tv.tv_sec, tv.tv_usec * NSEC_PER_USEC);
}
+/* check limitations for timeval provided by user */
+static bool bcm_is_invalid_tv(struct bcm_msg_head *msg_head)
+{
+ if ((msg_head->ival1.tv_sec < 0) ||
+ (msg_head->ival1.tv_sec > BCM_TIMER_SEC_MAX) ||
+ (msg_head->ival1.tv_usec < 0) ||
+ (msg_head->ival1.tv_usec >= USEC_PER_SEC) ||
+ (msg_head->ival2.tv_sec < 0) ||
+ (msg_head->ival2.tv_sec > BCM_TIMER_SEC_MAX) ||
+ (msg_head->ival2.tv_usec < 0) ||
+ (msg_head->ival2.tv_usec >= USEC_PER_SEC))
+ return true;
+
+ return false;
+}
+
#define CFSIZ(flags) ((flags & CAN_FD_FRAME) ? CANFD_MTU : CAN_MTU)
#define OPSIZ sizeof(struct bcm_op)
#define MHSIZ sizeof(struct bcm_msg_head)
@@ -873,6 +892,10 @@ static int bcm_tx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
if (msg_head->nframes < 1 || msg_head->nframes > MAX_NFRAMES)
return -EINVAL;
+ /* check timeval limitations */
+ if ((msg_head->flags & SETTIMER) && bcm_is_invalid_tv(msg_head))
+ return -EINVAL;
+
/* check the given can_id */
op = bcm_find_op(&bo->tx_ops, msg_head, ifindex);
if (op) {
@@ -1053,6 +1076,10 @@ static int bcm_rx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
(!(msg_head->can_id & CAN_RTR_FLAG))))
return -EINVAL;
+ /* check timeval limitations */
+ if ((msg_head->flags & SETTIMER) && bcm_is_invalid_tv(msg_head))
+ return -EINVAL;
+
/* check the given can_id */
op = bcm_find_op(&bo->rx_ops, msg_head, ifindex);
if (op) {