[PATCH v2] cfg80211: Fix array-bounds warning in fragment copy
From: Matthias Kaehlcke <mka@chromium.org>
Date: 2017-04-13 17:05:22
Also in:
linux-wireless, lkml
Subsystem:
802.11 (including cfg80211/nl80211), the rest · Maintainers:
Johannes Berg, Linus Torvalds
__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> --- Note: Resent to include linux-wireless in cc net/wireless/util.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/net/wireless/util.c b/net/wireless/util.c
index 68e5f2ecee1a..52795ae5337f 100644
--- a/net/wireless/util.c
+++ b/net/wireless/util.c@@ -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++; } }
--
2.12.2.715.g7642488e1d-goog