[PATCH v5 2/5] ipsec: check return value of skb_to_sgvec always

From: Jason A. Donenfeld
Date: Tue Apr 25 2017 - 11:53:39 EST


Signed-off-by: Jason A. Donenfeld <Jason@xxxxxxxxx>
---
net/ipv4/ah4.c | 8 ++++++--
net/ipv4/esp4.c | 30 ++++++++++++++++++++----------
net/ipv6/ah6.c | 8 ++++++--
net/ipv6/esp6.c | 31 +++++++++++++++++++++----------
4 files changed, 53 insertions(+), 24 deletions(-)

diff --git a/net/ipv4/ah4.c b/net/ipv4/ah4.c
index 22377c8ff14b..e8f862358518 100644
--- a/net/ipv4/ah4.c
+++ b/net/ipv4/ah4.c
@@ -220,7 +220,9 @@ static int ah_output(struct xfrm_state *x, struct sk_buff *skb)
ah->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);

sg_init_table(sg, nfrags + sglists);
- skb_to_sgvec_nomark(skb, sg, 0, skb->len);
+ err = skb_to_sgvec_nomark(skb, sg, 0, skb->len);
+ if (unlikely(err < 0))
+ goto out_free;

if (x->props.flags & XFRM_STATE_ESN) {
/* Attach seqhi sg right after packet payload */
@@ -393,7 +395,9 @@ static int ah_input(struct xfrm_state *x, struct sk_buff *skb)
skb_push(skb, ihl);

sg_init_table(sg, nfrags + sglists);
- skb_to_sgvec_nomark(skb, sg, 0, skb->len);
+ err = skb_to_sgvec_nomark(skb, sg, 0, skb->len);
+ if (unlikely(err < 0))
+ goto out_free;

if (x->props.flags & XFRM_STATE_ESN) {
/* Attach seqhi sg right after packet payload */
diff --git a/net/ipv4/esp4.c b/net/ipv4/esp4.c
index b1e24446e297..42cb09cc8533 100644
--- a/net/ipv4/esp4.c
+++ b/net/ipv4/esp4.c
@@ -360,9 +360,13 @@ static int esp_output(struct xfrm_state *x, struct sk_buff *skb)
esph = esp_output_set_extra(skb, esph, extra);

sg_init_table(sg, nfrags);
- skb_to_sgvec(skb, sg,
- (unsigned char *)esph - skb->data,
- assoclen + ivlen + clen + alen);
+ err = skb_to_sgvec(skb, sg,
+ (unsigned char *)esph - skb->data,
+ assoclen + ivlen + clen + alen);
+ if (unlikely(err < 0)) {
+ spin_unlock_bh(&x->lock);
+ goto error;
+ }

allocsize = ALIGN(skb->data_len, L1_CACHE_BYTES);

@@ -381,11 +385,13 @@ static int esp_output(struct xfrm_state *x, struct sk_buff *skb)
pfrag->offset = pfrag->offset + allocsize;

sg_init_table(dsg, skb_shinfo(skb)->nr_frags + 1);
- skb_to_sgvec(skb, dsg,
- (unsigned char *)esph - skb->data,
- assoclen + ivlen + clen + alen);
+ err = skb_to_sgvec(skb, dsg,
+ (unsigned char *)esph - skb->data,
+ assoclen + ivlen + clen + alen);

spin_unlock_bh(&x->lock);
+ if (unlikely(err < 0))
+ goto error;

goto skip_cow2;
}
@@ -422,9 +428,11 @@ static int esp_output(struct xfrm_state *x, struct sk_buff *skb)
esph = esp_output_set_extra(skb, esph, extra);

sg_init_table(sg, nfrags);
- skb_to_sgvec(skb, sg,
- (unsigned char *)esph - skb->data,
- assoclen + ivlen + clen + alen);
+ err = skb_to_sgvec(skb, sg,
+ (unsigned char *)esph - skb->data,
+ assoclen + ivlen + clen + alen);
+ if (unlikely(err < 0))
+ goto error;

skip_cow2:
if ((x->props.flags & XFRM_STATE_ESN))
@@ -658,7 +666,9 @@ static int esp_input(struct xfrm_state *x, struct sk_buff *skb)
esp_input_set_header(skb, seqhi);

sg_init_table(sg, nfrags);
- skb_to_sgvec(skb, sg, 0, skb->len);
+ err = skb_to_sgvec(skb, sg, 0, skb->len);
+ if (unlikely(err < 0))
+ goto out;

skb->ip_summed = CHECKSUM_NONE;

diff --git a/net/ipv6/ah6.c b/net/ipv6/ah6.c
index dda6035e3b84..755f38271dd5 100644
--- a/net/ipv6/ah6.c
+++ b/net/ipv6/ah6.c
@@ -423,7 +423,9 @@ static int ah6_output(struct xfrm_state *x, struct sk_buff *skb)
ah->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);

sg_init_table(sg, nfrags + sglists);
- skb_to_sgvec_nomark(skb, sg, 0, skb->len);
+ err = skb_to_sgvec_nomark(skb, sg, 0, skb->len);
+ if (unlikely(err < 0))
+ goto out_free;

if (x->props.flags & XFRM_STATE_ESN) {
/* Attach seqhi sg right after packet payload */
@@ -606,7 +608,9 @@ static int ah6_input(struct xfrm_state *x, struct sk_buff *skb)
ip6h->hop_limit = 0;

sg_init_table(sg, nfrags + sglists);
- skb_to_sgvec_nomark(skb, sg, 0, skb->len);
+ err = skb_to_sgvec_nomark(skb, sg, 0, skb->len);
+ if (unlikely(err < 0))
+ goto out_free;

if (x->props.flags & XFRM_STATE_ESN) {
/* Attach seqhi sg right after packet payload */
diff --git a/net/ipv6/esp6.c b/net/ipv6/esp6.c
index ff54faa75631..017e2c2d36e1 100644
--- a/net/ipv6/esp6.c
+++ b/net/ipv6/esp6.c
@@ -339,9 +339,13 @@ static int esp6_output(struct xfrm_state *x, struct sk_buff *skb)
esph = esp_output_set_esn(skb, esph, seqhi);

sg_init_table(sg, nfrags);
- skb_to_sgvec(skb, sg,
- (unsigned char *)esph - skb->data,
- assoclen + ivlen + clen + alen);
+ err = skb_to_sgvec(skb, sg,
+ (unsigned char *)esph - skb->data,
+ assoclen + ivlen + clen + alen);
+ if (unlikely(err < 0)) {
+ spin_unlock_bh(&x->lock);
+ goto error;
+ }

allocsize = ALIGN(skb->data_len, L1_CACHE_BYTES);

@@ -360,12 +364,15 @@ static int esp6_output(struct xfrm_state *x, struct sk_buff *skb)
pfrag->offset = pfrag->offset + allocsize;

sg_init_table(dsg, skb_shinfo(skb)->nr_frags + 1);
- skb_to_sgvec(skb, dsg,
- (unsigned char *)esph - skb->data,
- assoclen + ivlen + clen + alen);
+ err = skb_to_sgvec(skb, dsg,
+ (unsigned char *)esph - skb->data,
+ assoclen + ivlen + clen + alen);

spin_unlock_bh(&x->lock);

+ if (unlikely(err < 0))
+ goto error;
+
goto skip_cow2;
}
}
@@ -403,9 +410,11 @@ static int esp6_output(struct xfrm_state *x, struct sk_buff *skb)
esph = esp_output_set_esn(skb, esph, seqhi);

sg_init_table(sg, nfrags);
- skb_to_sgvec(skb, sg,
- (unsigned char *)esph - skb->data,
- assoclen + ivlen + clen + alen);
+ err = skb_to_sgvec(skb, sg,
+ (unsigned char *)esph - skb->data,
+ assoclen + ivlen + clen + alen);
+ if (unlikely(err < 0))
+ goto error;

skip_cow2:
if ((x->props.flags & XFRM_STATE_ESN))
@@ -600,7 +609,9 @@ static int esp6_input(struct xfrm_state *x, struct sk_buff *skb)
esp_input_set_header(skb, seqhi);

sg_init_table(sg, nfrags);
- skb_to_sgvec(skb, sg, 0, skb->len);
+ ret = skb_to_sgvec(skb, sg, 0, skb->len);
+ if (unlikely(ret < 0))
+ goto out;

skb->ip_summed = CHECKSUM_NONE;

--
2.12.2