* [PATCH] tcp: cookie transactions setsockopt memory leak
@ 2010-07-29 11:59 Dmitry Popov
2010-07-31 6:05 ` David Miller
0 siblings, 1 reply; 2+ messages in thread
From: Dmitry Popov @ 2010-07-29 11:59 UTC (permalink / raw)
To: David S. Miller, Alexey Kuznetsov, James Morris, Patrick McHardy
Cc: Pekka Savola (ipv6), Hideaki YOSHIFUJI, Eric Dumazet,
Ilpo Järvinen, Andrew Morton, Steven J. Magnani, netdev,
linux-kernel, William Allen Simpson
From: Dmitry Popov <dp@highloadlab.com>
There is a bug in do_tcp_setsockopt(net/ipv4/tcp.c),
TCP_COOKIE_TRANSACTIONS case.
In some cases (when tp->cookie_values == NULL) new tcp_cookie_values
structure can be allocated (at cvp), but not bound to
tp->cookie_values. So a memory leak occurs.
Signed-off-by: Dmitry Popov <dp@highloadlab.com>
---
tp->cookie_values can be NULL if socket was initialized with
sysctl_tcp_cookie_size == 0 (tcp_v4_init_sock, net/ipv4/tcp_ipv4.c)
Buggy releases: 2.6.33+ (since commit e56fb50f2b7958b931c8a2fc0966061b3f3c8f3a)
net/ipv4/tcp.c | 7 +++++--
1 files changed, 5 insertions(+), 2 deletions(-)
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 83d0213..9c490a1 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -2179,6 +2179,8 @@ static int do_tcp_setsockopt(struct sock *sk, int level,
GFP_KERNEL);
if (cvp == NULL)
return -ENOMEM;
+
+ kref_init(&cvp->kref);
}
lock_sock(sk);
tp->rx_opt.cookie_in_always =
@@ -2193,12 +2195,11 @@ static int do_tcp_setsockopt(struct sock *sk, int level,
*/
kref_put(&tp->cookie_values->kref,
tcp_cookie_values_release);
- kref_init(&cvp->kref);
- tp->cookie_values = cvp;
} else {
cvp = tp->cookie_values;
}
}
+
if (cvp != NULL) {
cvp->cookie_desired = ctd.tcpct_cookie_desired;
@@ -2212,6 +2213,8 @@ static int do_tcp_setsockopt(struct sock *sk, int level,
cvp->s_data_desired = ctd.tcpct_s_data_desired;
cvp->s_data_constant = 0; /* false */
}
+
+ tp->cookie_values = cvp;
}
release_sock(sk);
return err;
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] tcp: cookie transactions setsockopt memory leak
2010-07-29 11:59 [PATCH] tcp: cookie transactions setsockopt memory leak Dmitry Popov
@ 2010-07-31 6:05 ` David Miller
0 siblings, 0 replies; 2+ messages in thread
From: David Miller @ 2010-07-31 6:05 UTC (permalink / raw)
To: dp
Cc: kuznet, jmorris, kaber, pekkas, yoshfuji, eric.dumazet,
ilpo.jarvinen, akpm, steve, netdev, linux-kernel,
william.allen.simpson
From: Dmitry Popov <dp@highloadlab.com>
Date: Thu, 29 Jul 2010 15:59:36 +0400
> From: Dmitry Popov <dp@highloadlab.com>
>
> There is a bug in do_tcp_setsockopt(net/ipv4/tcp.c),
> TCP_COOKIE_TRANSACTIONS case.
> In some cases (when tp->cookie_values == NULL) new tcp_cookie_values
> structure can be allocated (at cvp), but not bound to
> tp->cookie_values. So a memory leak occurs.
>
> Signed-off-by: Dmitry Popov <dp@highloadlab.com>
Applied and queued up for -stable, thanks Dmitry.
^ permalink raw reply [flat|nested] 2+ messages in thread
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2010-07-31 6:05 ` David Miller
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