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| author | Sam Jansen <sjansen@google.com> | 2007-11-20 08:28:21 +0100 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2007-11-20 08:28:21 +0100 |
| commit | 5487796f0c9475586277a0a7a91211ce5746fa6a (patch) | |
| tree | 80ea156ec6f2b549706b57b267e1dcf327e0dde2 | |
| parent | [TCP] MTUprobe: fix potential sk_send_head corruption (diff) | |
| download | linux-5487796f0c9475586277a0a7a91211ce5746fa6a.tar.xz linux-5487796f0c9475586277a0a7a91211ce5746fa6a.zip | |
[TCP]: Problem bug with sysctl_tcp_congestion_control function
From: "Sam Jansen" <sjansen@google.com>
sysctl_tcp_congestion_control seems to have a bug that prevents it
from actually calling the tcp_set_default_congestion_control
function. This is not so apparent because it does not return an error
and generally the /proc interface is used to configure the default TCP
congestion control algorithm. This is present in 2.6.18 onwards and
probably earlier, though I have not inspected 2.6.15--2.6.17.
sysctl_tcp_congestion_control calls sysctl_string and expects a successful
return code of 0. In such a case it actually sets the congestion control
algorithm with tcp_set_default_congestion_control. Otherwise, it returns the
value returned by sysctl_string. This was correct in 2.6.14, as sysctl_string
returned 0 on success. However, sysctl_string was updated to return 1 on
success around about 2.6.15 and sysctl_tcp_congestion_control was not updated.
Even though sysctl_tcp_congestion_control returns 1, do_sysctl_strategy
converts this return code to '0', so the caller never notices the error.
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/ipv4/sysctl_net_ipv4.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c index ffddd2b45352..bec6fe880657 100644 --- a/net/ipv4/sysctl_net_ipv4.c +++ b/net/ipv4/sysctl_net_ipv4.c @@ -191,7 +191,7 @@ static int sysctl_tcp_congestion_control(ctl_table *table, int __user *name, tcp_get_default_congestion_control(val); ret = sysctl_string(&tbl, name, nlen, oldval, oldlenp, newval, newlen); - if (ret == 0 && newval && newlen) + if (ret == 1 && newval && newlen) ret = tcp_set_default_congestion_control(val); return ret; } |