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authorMartin Townsend <mtownsend1973@gmail.com>2014-11-06 22:15:13 +0300
committerMarcel Holtmann <marcel@holtmann.org>2014-11-07 00:09:48 +0300
commit56b2c3eea398c772dd895dc62c18cbdd1ba127b1 (patch)
treea4d6ab3f6bbf38f4c5b3cb66cc6f77d142397e32 /net/6lowpan/iphc.c
parent9645c76c7c233da82ff7aced0177c8a131a51e70 (diff)
downloadlinux-56b2c3eea398c772dd895dc62c18cbdd1ba127b1.tar.xz
6lowpan: move skb_free from error paths in decompression
Currently we ensure that the skb is freed on every error path in IPHC decompression which makes it easy to introduce skb leaks. By centralising the skb_free into the receive function it makes future decompression routines easier to maintain. It does come at the expense of ensuring that the skb passed into the decompression routine must not be copied. Signed-off-by: Martin Townsend <mtownsend1973@gmail.com> Acked-by: Jukka Rissanen <jukka.rissanen@linux.intel.com> Acked-by: Alexander Aring <alex.aring@gmail.com> Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Diffstat (limited to 'net/6lowpan/iphc.c')
-rw-r--r--net/6lowpan/iphc.c31
1 files changed, 12 insertions, 19 deletions
diff --git a/net/6lowpan/iphc.c b/net/6lowpan/iphc.c
index cd5f8b8e34cd..aced97db62f0 100644
--- a/net/6lowpan/iphc.c
+++ b/net/6lowpan/iphc.c
@@ -319,7 +319,7 @@ lowpan_header_decompress(struct sk_buff *skb, struct net_device *dev,
if (iphc1 & LOWPAN_IPHC_CID) {
pr_debug("CID flag is set, increase header with one\n");
if (lowpan_fetch_skb(skb, &num_context, sizeof(num_context)))
- goto drop;
+ return -EINVAL;
}
hdr.version = 6;
@@ -331,7 +331,7 @@ lowpan_header_decompress(struct sk_buff *skb, struct net_device *dev,
*/
case 0: /* 00b */
if (lowpan_fetch_skb(skb, &tmp, sizeof(tmp)))
- goto drop;
+ return -EINVAL;
memcpy(&hdr.flow_lbl, &skb->data[0], 3);
skb_pull(skb, 3);
@@ -344,7 +344,7 @@ lowpan_header_decompress(struct sk_buff *skb, struct net_device *dev,
*/
case 2: /* 10b */
if (lowpan_fetch_skb(skb, &tmp, sizeof(tmp)))
- goto drop;
+ return -EINVAL;
hdr.priority = ((tmp >> 2) & 0x0f);
hdr.flow_lbl[0] = ((tmp << 6) & 0xC0) | ((tmp >> 2) & 0x30);
@@ -354,7 +354,7 @@ lowpan_header_decompress(struct sk_buff *skb, struct net_device *dev,
*/
case 1: /* 01b */
if (lowpan_fetch_skb(skb, &tmp, sizeof(tmp)))
- goto drop;
+ return -EINVAL;
hdr.flow_lbl[0] = (skb->data[0] & 0x0F) | ((tmp >> 2) & 0x30);
memcpy(&hdr.flow_lbl[1], &skb->data[0], 2);
@@ -371,7 +371,7 @@ lowpan_header_decompress(struct sk_buff *skb, struct net_device *dev,
if ((iphc0 & LOWPAN_IPHC_NH_C) == 0) {
/* Next header is carried inline */
if (lowpan_fetch_skb(skb, &hdr.nexthdr, sizeof(hdr.nexthdr)))
- goto drop;
+ return -EINVAL;
pr_debug("NH flag is set, next header carried inline: %02x\n",
hdr.nexthdr);
@@ -383,7 +383,7 @@ lowpan_header_decompress(struct sk_buff *skb, struct net_device *dev,
} else {
if (lowpan_fetch_skb(skb, &hdr.hop_limit,
sizeof(hdr.hop_limit)))
- goto drop;
+ return -EINVAL;
}
/* Extract SAM to the tmp variable */
@@ -402,7 +402,7 @@ lowpan_header_decompress(struct sk_buff *skb, struct net_device *dev,
/* Check on error of previous branch */
if (err)
- goto drop;
+ return -EINVAL;
/* Extract DAM to the tmp variable */
tmp = ((iphc1 & LOWPAN_IPHC_DAM_11) >> LOWPAN_IPHC_DAM_BIT) & 0x03;
@@ -417,7 +417,7 @@ lowpan_header_decompress(struct sk_buff *skb, struct net_device *dev,
tmp);
if (err)
- goto drop;
+ return -EINVAL;
}
} else {
err = uncompress_addr(skb, &hdr.daddr, tmp, daddr,
@@ -425,7 +425,7 @@ lowpan_header_decompress(struct sk_buff *skb, struct net_device *dev,
pr_debug("dest: stateless compression mode %d dest %pI6c\n",
tmp, &hdr.daddr);
if (err)
- goto drop;
+ return -EINVAL;
}
/* UDP data uncompression */
@@ -434,16 +434,14 @@ lowpan_header_decompress(struct sk_buff *skb, struct net_device *dev,
const int needed = sizeof(struct udphdr) + sizeof(hdr);
if (uncompress_udp_header(skb, &uh))
- goto drop;
+ return -EINVAL;
/* replace the compressed UDP head by the uncompressed UDP
* header
*/
err = skb_cow(skb, needed);
- if (unlikely(err)) {
- kfree_skb(skb);
+ if (unlikely(err))
return err;
- }
skb_push(skb, sizeof(struct udphdr));
skb_reset_transport_header(skb);
@@ -455,10 +453,8 @@ lowpan_header_decompress(struct sk_buff *skb, struct net_device *dev,
hdr.nexthdr = UIP_PROTO_UDP;
} else {
err = skb_cow(skb, sizeof(hdr));
- if (unlikely(err)) {
- kfree_skb(skb);
+ if (unlikely(err))
return err;
- }
}
hdr.payload_len = htons(skb->len);
@@ -478,9 +474,6 @@ lowpan_header_decompress(struct sk_buff *skb, struct net_device *dev,
raw_dump_table(__func__, "raw header dump", (u8 *)&hdr, sizeof(hdr));
return 0;
-drop:
- kfree_skb(skb);
- return -EINVAL;
}
EXPORT_SYMBOL_GPL(lowpan_header_decompress);