4.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Willem de Bruijn <will...@google.com>
[ Upstream commit fff88030b3ff930ca7a3d74acfee0472f33887ea ]
When inheriting tx_flags from one skbuff to another, always apply a
mask to avoid overwriting unrelated other bits in the field.
The two SKBTX_SHARED_FRAG cases clears all other bits. In practice,
tx_flags are zero at this point now. But this is fragile. Timestamp
flags are set, for instance, if in tcp_gso_segment, after this clear
in skb_segment.
The SKBTX_ANY_TSTAMP mask in __skb_tstamp_tx ensures that new
skbs do not accidentally inherit flags such as SKBTX_SHARED_FRAG.
Signed-off-by: Willem de Bruijn <will...@google.com>
Acked-by: Soheil Hassas Yeganeh <soh...@google.com>
Acked-by: Eric Dumazet <eduma...@google.com>
Signed-off-by: David S. Miller <da...@davemloft.net>
Signed-off-by: Sasha Levin <alexander.le...@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
net/core/skbuff.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -2551,7 +2551,8 @@ void skb_split(struct sk_buff *skb, stru
{
int pos = skb_headlen(skb);
- skb_shinfo(skb1)->tx_flags = skb_shinfo(skb)->tx_flags &
SKBTX_SHARED_FRAG;
+ skb_shinfo(skb1)->tx_flags |= skb_shinfo(skb)->tx_flags &
+ SKBTX_SHARED_FRAG;
if (len < pos) /* Split line is inside header. */
skb_split_inside_header(skb, skb1, len, pos);
else /* Second chunk has no header, nothing to copy. */
@@ -3115,8 +3116,8 @@ struct sk_buff *skb_segment(struct sk_bu
skb_copy_from_linear_data_offset(head_skb, offset,
skb_put(nskb, hsize), hsize);
- skb_shinfo(nskb)->tx_flags = skb_shinfo(head_skb)->tx_flags &
- SKBTX_SHARED_FRAG;
+ skb_shinfo(nskb)->tx_flags |= skb_shinfo(head_skb)->tx_flags &
+ SKBTX_SHARED_FRAG;
while (pos < offset + len) {
if (i >= nfrags) {
@@ -3734,7 +3735,8 @@ void __skb_tstamp_tx(struct sk_buff *ori
return;
if (tsonly) {
- skb_shinfo(skb)->tx_flags = skb_shinfo(orig_skb)->tx_flags;
+ skb_shinfo(skb)->tx_flags |= skb_shinfo(orig_skb)->tx_flags &
+ SKBTX_ANY_TSTAMP;
skb_shinfo(skb)->tskey = skb_shinfo(orig_skb)->tskey;
}
