diff options
| author | Oliver Hartkopp <socketcan@hartkopp.net> | 2019-01-13 19:31:43 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-02-06 19:43:04 +0100 |
| commit | 8781bfdf733ec4c078454535f1354fc915a13786 (patch) | |
| tree | eadd63a9aeb56237fd6c2d898132a2232b57fb3f /net/can | |
| parent | 17cb93920405fe8d7105191cc1733cc8a4e2d19e (diff) | |
can: bcm: check timer values before ktime conversion
commit 93171ba6f1deffd82f381d36cb13177872d023f6 upstream.
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> # versions 2.6.26 to 4.7
Tested-by: Kyungtae Kim <kt0755@gmail.com>
Acked-by: Andre Naujoks <nautsch2@gmail.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net/can')
| -rw-r--r-- | net/can/bcm.c | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/net/can/bcm.c b/net/can/bcm.c index 4ccfd356baed..1f15622d3c65 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].can_dlc */ #define RX_RECV 0x40 /* received data for this element */ #define RX_THR 0x80 /* element not been sent due to throttle feature */ @@ -136,6 +139,22 @@ 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 sizeof(struct can_frame) #define OPSIZ sizeof(struct bcm_op) #define MHSIZ sizeof(struct bcm_msg_head) @@ -855,6 +874,10 @@ 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->can_id, ifindex); @@ -1020,6 +1043,10 @@ 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->can_id, ifindex); if (op) { |