From: Jakub Kicinski kuba@kernel.org
[ Upstream commit 8b0c0dc9fbbd01e58a573a41c38885f9e4c17696 ]
We call tls_rx_msg_size(skb) before doing skb->len += chunk. So the tls_rx_msg_size() code will see old skb->len, most likely leading to an over-read.
Worst case we will over read an entire record, next iteration will try to trim the skb but may end up turning frag len negative or discarding the subsequent record (since we already told TCP we've read it during previous read but now we'll trim it out of the skb).
Fixes: 84c61fe1a75b ("tls: rx: do not use the standard strparser") Tested-by: Shai Amiram samiram@nvidia.com Signed-off-by: Jakub Kicinski kuba@kernel.org Reviewed-by: Simon Horman simon.horman@corigine.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- net/tls/tls_strp.c | 21 +++++++++++++++------ 1 file changed, 15 insertions(+), 6 deletions(-)
diff --git a/net/tls/tls_strp.c b/net/tls/tls_strp.c index 24016c865e004..9889df5ce0660 100644 --- a/net/tls/tls_strp.c +++ b/net/tls/tls_strp.c @@ -210,19 +210,28 @@ static int tls_strp_copyin(read_descriptor_t *desc, struct sk_buff *in_skb, skb_frag_size(frag), chunk));
- sz = tls_rx_msg_size(strp, strp->anchor); + skb->len += chunk; + skb->data_len += chunk; + skb_frag_size_add(frag, chunk); + + sz = tls_rx_msg_size(strp, skb); if (sz < 0) { desc->error = sz; return 0; }
/* We may have over-read, sz == 0 is guaranteed under-read */ - if (sz > 0) - chunk = min_t(size_t, chunk, sz - skb->len); + if (unlikely(sz && sz < skb->len)) { + int over = skb->len - sz; + + WARN_ON_ONCE(over > chunk); + skb->len -= over; + skb->data_len -= over; + skb_frag_size_add(frag, -over); + + chunk -= over; + }
- skb->len += chunk; - skb->data_len += chunk; - skb_frag_size_add(frag, chunk); frag++; len -= chunk; offset += chunk;