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authorOliver Hartkopp <oliver.hartkopp@volkswagen.de>2008-07-06 02:38:43 -0400
committerDavid S. Miller <davem@davemloft.net>2008-07-06 02:38:43 -0400
commit7f2d38eb7a42bea1c1df51bbdaa2ca0f0bdda07f (patch)
tree930ee4b119242ea70d020521f217b42090e42b6e /net
parentc5a78ac00c400df29645e59938700301efb371d0 (diff)
can: add sanity checks
Even though the CAN netlayer only deals with CAN netdevices, the netlayer interface to the userspace and to the device layer should perform some sanity checks. This patch adds several sanity checks that mainly prevent userspace apps to send broken content into the system that may be misinterpreted by some other userspace application. Signed-off-by: Oliver Hartkopp <oliver.hartkopp@volkswagen.de> Signed-off-by: Urs Thuermann <urs.thuermann@volkswagen.de> Acked-by: Andre Naujoks <nautsch@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/can/af_can.c10
-rw-r--r--net/can/bcm.c23
-rw-r--r--net/can/raw.c3
3 files changed, 32 insertions, 4 deletions
diff --git a/net/can/af_can.c b/net/can/af_can.c
index 7e8ca283645..484bbf6dd03 100644
--- a/net/can/af_can.c
+++ b/net/can/af_can.c
@@ -205,12 +205,19 @@ static int can_create(struct net *net, struct socket *sock, int protocol)
205 * -ENOBUFS on full driver queue (see net_xmit_errno()) 205 * -ENOBUFS on full driver queue (see net_xmit_errno())
206 * -ENOMEM when local loopback failed at calling skb_clone() 206 * -ENOMEM when local loopback failed at calling skb_clone()
207 * -EPERM when trying to send on a non-CAN interface 207 * -EPERM when trying to send on a non-CAN interface
208 * -EINVAL when the skb->data does not contain a valid CAN frame
208 */ 209 */
209int can_send(struct sk_buff *skb, int loop) 210int can_send(struct sk_buff *skb, int loop)
210{ 211{
211 struct sk_buff *newskb = NULL; 212 struct sk_buff *newskb = NULL;
213 struct can_frame *cf = (struct can_frame *)skb->data;
212 int err; 214 int err;
213 215
216 if (skb->len != sizeof(struct can_frame) || cf->can_dlc > 8) {
217 kfree_skb(skb);
218 return -EINVAL;
219 }
220
214 if (skb->dev->type != ARPHRD_CAN) { 221 if (skb->dev->type != ARPHRD_CAN) {
215 kfree_skb(skb); 222 kfree_skb(skb);
216 return -EPERM; 223 return -EPERM;
@@ -605,6 +612,7 @@ static int can_rcv(struct sk_buff *skb, struct net_device *dev,
605 struct packet_type *pt, struct net_device *orig_dev) 612 struct packet_type *pt, struct net_device *orig_dev)
606{ 613{
607 struct dev_rcv_lists *d; 614 struct dev_rcv_lists *d;
615 struct can_frame *cf = (struct can_frame *)skb->data;
608 int matches; 616 int matches;
609 617
610 if (dev->type != ARPHRD_CAN || dev_net(dev) != &init_net) { 618 if (dev->type != ARPHRD_CAN || dev_net(dev) != &init_net) {
@@ -612,6 +620,8 @@ static int can_rcv(struct sk_buff *skb, struct net_device *dev,
612 return 0; 620 return 0;
613 } 621 }
614 622
623 BUG_ON(skb->len != sizeof(struct can_frame) || cf->can_dlc > 8);
624
615 /* update statistics */ 625 /* update statistics */
616 can_stats.rx_frames++; 626 can_stats.rx_frames++;
617 can_stats.rx_frames_delta++; 627 can_stats.rx_frames_delta++;
diff --git a/net/can/bcm.c b/net/can/bcm.c
index d9a3a9d13be..72c2ce904f8 100644
--- a/net/can/bcm.c
+++ b/net/can/bcm.c
@@ -298,7 +298,7 @@ static void bcm_send_to_user(struct bcm_op *op, struct bcm_msg_head *head,
298 298
299 if (head->nframes) { 299 if (head->nframes) {
300 /* can_frames starting here */ 300 /* can_frames starting here */
301 firstframe = (struct can_frame *) skb_tail_pointer(skb); 301 firstframe = (struct can_frame *)skb_tail_pointer(skb);
302 302
303 memcpy(skb_put(skb, datalen), frames, datalen); 303 memcpy(skb_put(skb, datalen), frames, datalen);
304 304
@@ -826,6 +826,10 @@ static int bcm_tx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
826 for (i = 0; i < msg_head->nframes; i++) { 826 for (i = 0; i < msg_head->nframes; i++) {
827 err = memcpy_fromiovec((u8 *)&op->frames[i], 827 err = memcpy_fromiovec((u8 *)&op->frames[i],
828 msg->msg_iov, CFSIZ); 828 msg->msg_iov, CFSIZ);
829
830 if (op->frames[i].can_dlc > 8)
831 err = -EINVAL;
832
829 if (err < 0) 833 if (err < 0)
830 return err; 834 return err;
831 835
@@ -858,6 +862,10 @@ static int bcm_tx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
858 for (i = 0; i < msg_head->nframes; i++) { 862 for (i = 0; i < msg_head->nframes; i++) {
859 err = memcpy_fromiovec((u8 *)&op->frames[i], 863 err = memcpy_fromiovec((u8 *)&op->frames[i],
860 msg->msg_iov, CFSIZ); 864 msg->msg_iov, CFSIZ);
865
866 if (op->frames[i].can_dlc > 8)
867 err = -EINVAL;
868
861 if (err < 0) { 869 if (err < 0) {
862 if (op->frames != &op->sframe) 870 if (op->frames != &op->sframe)
863 kfree(op->frames); 871 kfree(op->frames);
@@ -1164,9 +1172,12 @@ static int bcm_tx_send(struct msghdr *msg, int ifindex, struct sock *sk)
1164 1172
1165 skb->dev = dev; 1173 skb->dev = dev;
1166 skb->sk = sk; 1174 skb->sk = sk;
1167 can_send(skb, 1); /* send with loopback */ 1175 err = can_send(skb, 1); /* send with loopback */
1168 dev_put(dev); 1176 dev_put(dev);
1169 1177
1178 if (err)
1179 return err;
1180
1170 return CFSIZ + MHSIZ; 1181 return CFSIZ + MHSIZ;
1171} 1182}
1172 1183
@@ -1185,6 +1196,10 @@ static int bcm_sendmsg(struct kiocb *iocb, struct socket *sock,
1185 if (!bo->bound) 1196 if (!bo->bound)
1186 return -ENOTCONN; 1197 return -ENOTCONN;
1187 1198
1199 /* check for valid message length from userspace */
1200 if (size < MHSIZ || (size - MHSIZ) % CFSIZ)
1201 return -EINVAL;
1202
1188 /* check for alternative ifindex for this bcm_op */ 1203 /* check for alternative ifindex for this bcm_op */
1189 1204
1190 if (!ifindex && msg->msg_name) { 1205 if (!ifindex && msg->msg_name) {
@@ -1259,8 +1274,8 @@ static int bcm_sendmsg(struct kiocb *iocb, struct socket *sock,
1259 break; 1274 break;
1260 1275
1261 case TX_SEND: 1276 case TX_SEND:
1262 /* we need at least one can_frame */ 1277 /* we need exactly one can_frame behind the msg head */
1263 if (msg_head.nframes < 1) 1278 if ((msg_head.nframes != 1) || (size != CFSIZ + MHSIZ))
1264 ret = -EINVAL; 1279 ret = -EINVAL;
1265 else 1280 else
1266 ret = bcm_tx_send(msg, ifindex, sk); 1281 ret = bcm_tx_send(msg, ifindex, sk);
diff --git a/net/can/raw.c b/net/can/raw.c
index 69877b8e7e9..3e46ee36a1a 100644
--- a/net/can/raw.c
+++ b/net/can/raw.c
@@ -632,6 +632,9 @@ static int raw_sendmsg(struct kiocb *iocb, struct socket *sock,
632 } else 632 } else
633 ifindex = ro->ifindex; 633 ifindex = ro->ifindex;
634 634
635 if (size != sizeof(struct can_frame))
636 return -EINVAL;
637
635 dev = dev_get_by_index(&init_net, ifindex); 638 dev = dev_get_by_index(&init_net, ifindex);
636 if (!dev) 639 if (!dev)
637 return -ENXIO; 640 return -ENXIO;