4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Matthias Kaehlcke <mka@xxxxxxxxxxxx>
commit aa1702dd162f420bf85ecef0c77686ef0dbc1496 upstream.
__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@xxxxxxxxxxxx>
Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
Cc: Nathan Chancellor <natechancellor@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/wireless/util.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -663,7 +663,7 @@ __ieee80211_amsdu_copy_frag(struct sk_bu
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;
@@ -676,10 +676,10 @@ __ieee80211_amsdu_copy_frag(struct sk_bu
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;
@@ -691,12 +691,12 @@ __ieee80211_amsdu_copy_frag(struct sk_bu
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++;
}
}