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authorEric B Munson <emunson@akamai.com>2015-05-18 14:35:58 -0400
committerDavid S. Miller <davem@davemloft.net>2015-05-19 16:33:34 -0400
commitaea0929e516a1ff4c4458203d1f3375eee9acc26 (patch)
treedd499751b35707afda3144e78261f710b34671e6 /net
parentc9a70d43461d83818825ae065bb8fc887421e150 (diff)
tcp: Return error instead of partial read for saved syn headers
Currently the getsockopt() requesting the cached contents of the syn packet headers will fail silently if the caller uses a buffer that is too small to contain the requested data. Rather than fail silently and discard the headers, getsockopt() should return an error and report the required size to hold the data. Signed-off-by: Eric B Munson <emunson@akamai.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> Cc: James Morris <jmorris@namei.org> Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org> Cc: Patrick McHardy <kaber@trash.net> Cc: netdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/ipv4/tcp.c10
1 files changed, 9 insertions, 1 deletions
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index c724195e5862..bb9bb844204f 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -2845,7 +2845,15 @@ static int do_tcp_getsockopt(struct sock *sk, int level,
lock_sock(sk);
if (tp->saved_syn) {
- len = min_t(unsigned int, tp->saved_syn[0], len);
+ if (len < tp->saved_syn[0]) {
+ if (put_user(tp->saved_syn[0], optlen)) {
+ release_sock(sk);
+ return -EFAULT;
+ }
+ release_sock(sk);
+ return -EINVAL;
+ }
+ len = tp->saved_syn[0];
if (put_user(len, optlen)) {
release_sock(sk);
return -EFAULT;