diff options
| author | Kuniyuki Iwashima <kuniyu@amazon.com> | 2022-07-18 10:26:44 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2022-07-20 10:14:49 +0100 |
| commit | 3666f666e99600518ab20982af04a078bbdad277 (patch) | |
| tree | 1cd7759fdd31cddc102b72d376ba6af18abd6460 /net/ipv4/syncookies.c | |
| parent | 3d72bb4188c708bb16758c60822fc4dda7a95174 (diff) | |
| download | linux-stable-3666f666e99600518ab20982af04a078bbdad277.tar.gz linux-stable-3666f666e99600518ab20982af04a078bbdad277.tar.bz2 linux-stable-3666f666e99600518ab20982af04a078bbdad277.zip | |
tcp: Fix data-races around sysctl knobs related to SYN option.
While reading these knobs, they can be changed concurrently.
Thus, we need to add READ_ONCE() to their readers.
- tcp_sack
- tcp_window_scaling
- tcp_timestamps
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/syncookies.c')
| -rw-r--r-- | net/ipv4/syncookies.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/net/ipv4/syncookies.c b/net/ipv4/syncookies.c index 9b234b42021e..942d2dfa1115 100644 --- a/net/ipv4/syncookies.c +++ b/net/ipv4/syncookies.c @@ -247,12 +247,12 @@ bool cookie_timestamp_decode(const struct net *net, return true; } - if (!net->ipv4.sysctl_tcp_timestamps) + if (!READ_ONCE(net->ipv4.sysctl_tcp_timestamps)) return false; tcp_opt->sack_ok = (options & TS_OPT_SACK) ? TCP_SACK_SEEN : 0; - if (tcp_opt->sack_ok && !net->ipv4.sysctl_tcp_sack) + if (tcp_opt->sack_ok && !READ_ONCE(net->ipv4.sysctl_tcp_sack)) return false; if ((options & TS_OPT_WSCALE_MASK) == TS_OPT_WSCALE_MASK) @@ -261,7 +261,7 @@ bool cookie_timestamp_decode(const struct net *net, tcp_opt->wscale_ok = 1; tcp_opt->snd_wscale = options & TS_OPT_WSCALE_MASK; - return net->ipv4.sysctl_tcp_window_scaling != 0; + return READ_ONCE(net->ipv4.sysctl_tcp_window_scaling) != 0; } EXPORT_SYMBOL(cookie_timestamp_decode); |