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| author | Oliver Hartkopp <socketcan@hartkopp.net> | 2019-01-13 19:31:43 +0100 |
|---|---|---|
| committer | Marc Kleine-Budde <mkl@pengutronix.de> | 2019-01-22 11:33:46 +0100 |
| commit | 93171ba6f1deffd82f381d36cb13177872d023f6 (patch) | |
| tree | 5f561038080d2b31941a39fec548e60edfc28e4c /net | |
| parent | 7b12c8189a3dc50638e7d53714c88007268d47ef (diff) | |
| download | linux-93171ba6f1deffd82f381d36cb13177872d023f6.tar.gz linux-93171ba6f1deffd82f381d36cb13177872d023f6.tar.bz2 linux-93171ba6f1deffd82f381d36cb13177872d023f6.zip | |
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')
| -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 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) { |