diff options
| -rw-r--r-- | include/linux/skbuff.h | 8 | ||||
| -rw-r--r-- | net/core/skbuff.c | 65 |
2 files changed, 46 insertions, 27 deletions
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 45a59c1e0cc7..d460a4cbda1c 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -953,10 +953,10 @@ struct sk_buff *skb_realloc_headroom(struct sk_buff *skb, unsigned int headroom); struct sk_buff *skb_copy_expand(const struct sk_buff *skb, int newheadroom, int newtailroom, gfp_t priority); -int skb_to_sgvec_nomark(struct sk_buff *skb, struct scatterlist *sg, - int offset, int len); -int skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg, int offset, - int len); +int __must_check skb_to_sgvec_nomark(struct sk_buff *skb, struct scatterlist *sg, + int offset, int len); +int __must_check skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg, + int offset, int len); int skb_cow_data(struct sk_buff *skb, int tailbits, struct sk_buff **trailer); int skb_pad(struct sk_buff *skb, int pad); #define dev_kfree_skb(a) consume_skb(a) diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 780b7c1563d0..bba33cf4f7cd 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -3508,24 +3508,18 @@ void __init skb_init(void) NULL); } -/** - * skb_to_sgvec - Fill a scatter-gather list from a socket buffer - * @skb: Socket buffer containing the buffers to be mapped - * @sg: The scatter-gather list to map into - * @offset: The offset into the buffer's contents to start mapping - * @len: Length of buffer space to be mapped - * - * Fill the specified scatter-gather list with mappings/pointers into a - * region of the buffer space attached to a socket buffer. - */ static int -__skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg, int offset, int len) +__skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg, int offset, int len, + unsigned int recursion_level) { int start = skb_headlen(skb); int i, copy = start - offset; struct sk_buff *frag_iter; int elt = 0; + if (unlikely(recursion_level >= 24)) + return -EMSGSIZE; + if (copy > 0) { if (copy > len) copy = len; @@ -3544,6 +3538,8 @@ __skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg, int offset, int len) end = start + skb_frag_size(&skb_shinfo(skb)->frags[i]); if ((copy = end - offset) > 0) { skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; + if (unlikely(elt && sg_is_last(&sg[elt - 1]))) + return -EMSGSIZE; if (copy > len) copy = len; @@ -3558,16 +3554,22 @@ __skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg, int offset, int len) } skb_walk_frags(skb, frag_iter) { - int end; + int end, ret; WARN_ON(start > offset + len); end = start + frag_iter->len; if ((copy = end - offset) > 0) { + if (unlikely(elt && sg_is_last(&sg[elt - 1]))) + return -EMSGSIZE; + if (copy > len) copy = len; - elt += __skb_to_sgvec(frag_iter, sg+elt, offset - start, - copy); + ret = __skb_to_sgvec(frag_iter, sg+elt, offset - start, + copy, recursion_level + 1); + if (unlikely(ret < 0)) + return ret; + elt += ret; if ((len -= copy) == 0) return elt; offset += copy; @@ -3578,6 +3580,31 @@ __skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg, int offset, int len) return elt; } +/** + * skb_to_sgvec - Fill a scatter-gather list from a socket buffer + * @skb: Socket buffer containing the buffers to be mapped + * @sg: The scatter-gather list to map into + * @offset: The offset into the buffer's contents to start mapping + * @len: Length of buffer space to be mapped + * + * Fill the specified scatter-gather list with mappings/pointers into a + * region of the buffer space attached to a socket buffer. Returns either + * the number of scatterlist items used, or -EMSGSIZE if the contents + * could not fit. + */ +int skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg, int offset, int len) +{ + int nsg = __skb_to_sgvec(skb, sg, offset, len, 0); + + if (nsg <= 0) + return nsg; + + sg_mark_end(&sg[nsg - 1]); + + return nsg; +} +EXPORT_SYMBOL_GPL(skb_to_sgvec); + /* As compared with skb_to_sgvec, skb_to_sgvec_nomark only map skb to given * sglist without mark the sg which contain last skb data as the end. * So the caller can mannipulate sg list as will when padding new data after @@ -3600,19 +3627,11 @@ __skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg, int offset, int len) int skb_to_sgvec_nomark(struct sk_buff *skb, struct scatterlist *sg, int offset, int len) { - return __skb_to_sgvec(skb, sg, offset, len); + return __skb_to_sgvec(skb, sg, offset, len, 0); } EXPORT_SYMBOL_GPL(skb_to_sgvec_nomark); -int skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg, int offset, int len) -{ - int nsg = __skb_to_sgvec(skb, sg, offset, len); - sg_mark_end(&sg[nsg - 1]); - - return nsg; -} -EXPORT_SYMBOL_GPL(skb_to_sgvec); /** * skb_cow_data - Check that a socket buffer's data buffers are writable |