cfg80211: Fix array-bounds warning in fragment copy

__ieee80211_amsdu_copy_frag intentionally initializes a pointer to
array[-1] to increment it later to valid values. clang rightfully
generates an array-bounds warning on the initialization statement.

Initialize the pointer to array[0] and change the algorithm from
increment before to increment after consume.

Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
This commit is contained in:
Matthias Kaehlcke 2017-04-13 10:05:04 -07:00 committed by Johannes Berg
parent f64331d580
commit aa1702dd16

View File

@ -659,7 +659,7 @@ __ieee80211_amsdu_copy_frag(struct sk_buff *skb, struct sk_buff *frame,
int offset, int len)
{
struct skb_shared_info *sh = skb_shinfo(skb);
const skb_frag_t *frag = &sh->frags[-1];
const skb_frag_t *frag = &sh->frags[0];
struct page *frag_page;
void *frag_ptr;
int frag_len, frag_size;
@ -672,10 +672,10 @@ __ieee80211_amsdu_copy_frag(struct sk_buff *skb, struct sk_buff *frame,
while (offset >= frag_size) {
offset -= frag_size;
frag++;
frag_page = skb_frag_page(frag);
frag_ptr = skb_frag_address(frag);
frag_size = skb_frag_size(frag);
frag++;
}
frag_ptr += offset;
@ -687,12 +687,12 @@ __ieee80211_amsdu_copy_frag(struct sk_buff *skb, struct sk_buff *frame,
len -= cur_len;
while (len > 0) {
frag++;
frag_len = skb_frag_size(frag);
cur_len = min(len, frag_len);
__frame_add_frag(frame, skb_frag_page(frag),
skb_frag_address(frag), cur_len, frag_len);
len -= cur_len;
frag++;
}
}