net: Fix usage of pskb_trim_rcsum
[ Upstream commit 6c57f0458022298e4da1729c67bd33ce41c14e7a ]
In certain cases, pskb_trim_rcsum() may change skb pointers.
Reinitialize header pointers afterwards to avoid potential
use-after-frees. Add a note in the documentation of
pskb_trim_rcsum(). Found by KASAN.
Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/net/ipv4/ip_input.c b/net/ipv4/ip_input.c
index d6feabb..bcadca2 100644
--- a/net/ipv4/ip_input.c
+++ b/net/ipv4/ip_input.c
@@ -475,6 +475,7 @@
goto drop;
}
+ iph = ip_hdr(skb);
skb->transport_header = skb->network_header + iph->ihl*4;
/* Remove any debris in the socket control block */