diff options
author | Dimitris Michailidis <dm@chelsio.com> | 2009-01-27 09:15:31 +0300 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2009-01-27 09:15:31 +0300 |
commit | 9fa5fdf291c9b58b1cb8b4bb2a0ee57efa21d635 (patch) | |
tree | cfa28bcf674ef224a5ab66b3b8bc4bc1091ccb11 /net/ipv4 | |
parent | a7a41acf99d9150b424839b0d7b4f5ad9d211e2d (diff) | |
download | linux-9fa5fdf291c9b58b1cb8b4bb2a0ee57efa21d635.tar.xz |
tcp: Fix length tcp_splice_data_recv passes to skb_splice_bits.
tcp_splice_data_recv has two lengths to consider: the len parameter it
gets from tcp_read_sock, which specifies the amount of data in the skb,
and rd_desc->count, which is the amount of data the splice caller still
wants. Currently it passes just the latter to skb_splice_bits, which then
splices min(rd_desc->count, skb->len - offset) bytes.
Most of the time this is fine, except when the skb contains urgent data.
In that case len goes only up to the urgent byte and is less than
skb->len - offset. By ignoring len tcp_splice_data_recv may a) splice
data tcp_read_sock told it not to, b) return to tcp_read_sock a value > len.
Now, tcp_read_sock doesn't handle used > len and leaves the socket in a
bad state (both sk_receive_queue and copied_seq are bad at that point)
resulting in duplicated data and corruption.
Fix by passing min(rd_desc->count, len) to skb_splice_bits.
Signed-off-by: Dimitris Michailidis <dm@chelsio.com>
Acked-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4')
-rw-r--r-- | net/ipv4/tcp.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 0cd71b84e483..76b148bcb0dc 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -524,7 +524,8 @@ static int tcp_splice_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, struct tcp_splice_state *tss = rd_desc->arg.data; int ret; - ret = skb_splice_bits(skb, offset, tss->pipe, rd_desc->count, tss->flags); + ret = skb_splice_bits(skb, offset, tss->pipe, min(rd_desc->count, len), + tss->flags); if (ret > 0) rd_desc->count -= ret; return ret; |