* [PATCH v2 net-next] tcp-zerocopy: Update returned getsockopt() optlen.
@ 2020-02-25 20:38 Arjun Roy
2020-02-27 4:24 ` David Miller
0 siblings, 1 reply; 2+ messages in thread
From: Arjun Roy @ 2020-02-25 20:38 UTC (permalink / raw)
To: davem, netdev; +Cc: arjunroy, soheil, edumazet, willemb
From: Arjun Roy <arjunroy@google.com>
TCP receive zerocopy currently does not update the returned optlen for
getsockopt() if the user passed in a larger than expected value.
Thus, userspace cannot properly determine if all the fields are set in
the passed-in struct. This patch sets the optlen for this case before
returning, in keeping with the expected operation of getsockopt().
Fixes: c8856c051454 ("tcp-zerocopy: Return inq along with tcp receive zerocopy.")
Signed-off-by: Arjun Roy <arjunroy@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: Willem de Bruijn <willemb@google.com>
---
net/ipv4/tcp.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 600deb39f17de..9644047262ece 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -4124,8 +4124,11 @@ static int do_tcp_getsockopt(struct sock *sk, int level,
return -EFAULT;
if (len < offsetofend(struct tcp_zerocopy_receive, length))
return -EINVAL;
- if (len > sizeof(zc))
+ if (len > sizeof(zc)) {
len = sizeof(zc);
+ if (put_user(len, optlen))
+ return -EFAULT;
+ }
if (copy_from_user(&zc, optval, len))
return -EFAULT;
lock_sock(sk);
--
2.25.0.265.gbab2e86ba0-goog
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH v2 net-next] tcp-zerocopy: Update returned getsockopt() optlen.
2020-02-25 20:38 [PATCH v2 net-next] tcp-zerocopy: Update returned getsockopt() optlen Arjun Roy
@ 2020-02-27 4:24 ` David Miller
0 siblings, 0 replies; 2+ messages in thread
From: David Miller @ 2020-02-27 4:24 UTC (permalink / raw)
To: arjunroy.kdev; +Cc: netdev, arjunroy, soheil, edumazet, willemb
From: Arjun Roy <arjunroy.kdev@gmail.com>
Date: Tue, 25 Feb 2020 12:38:54 -0800
> From: Arjun Roy <arjunroy@google.com>
>
> TCP receive zerocopy currently does not update the returned optlen for
> getsockopt() if the user passed in a larger than expected value.
> Thus, userspace cannot properly determine if all the fields are set in
> the passed-in struct. This patch sets the optlen for this case before
> returning, in keeping with the expected operation of getsockopt().
>
> Fixes: c8856c051454 ("tcp-zerocopy: Return inq along with tcp receive zerocopy.")
> Signed-off-by: Arjun Roy <arjunroy@google.com>
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com>
> Signed-off-by: Willem de Bruijn <willemb@google.com>
Applied, thank you.
^ permalink raw reply [flat|nested] 2+ messages in thread
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