Ping?
If you have no time I can just ask Dave. But please drop me a short note.
Thanks,
Oliver
On 17.01.19 17:04, Oliver Hartkopp wrote:
Hello Marc,
I would like to provide a stable patch for pre-4.18 kernels and need a
commit hash as reference.
Would you like to take that patch into upstream?
Best regards,
Oliver
On 1/16/19 2:31 PM, Andre Naujoks wrote:
Am 13.01.19 um 19:31 schrieb Oliver Hartkopp:
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@xxxxxxxxx>
Tested-by: Oliver Hartkopp <socketcan@xxxxxxxxxxxx>
Signed-off-by: Oliver Hartkopp <socketcan@xxxxxxxxxxxx>
Cc: linux-stable <stable@xxxxxxxxxxxxxxx> # >= 2.6.26
Acked-by: Andre Naujoks <nautsch2@xxxxxxxxx>
Sorry for the late reply, but I seem to have missed the initial send of
v2 of this. I wanted to at least ack it, since I made such a fuss about
the timeouts. :-)
Regards
Andre
---
net/can/bcm.c | 27 +++++++++++++++++++++++++++
1 file changed, 27 insertions(+)
diff --git a/net/can/bcm.c b/net/can/bcm.c
index 0af8f0db892a..d4ae0a1471f3 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 int 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 1;
+
+ return 0;
+}
+
#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) {
