lkml.org 
[lkml]   [2022]   [Jul]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 5.15 100/201] tcp: Fix data-races around sysctl_tcp_fastopen_blackhole_timeout.
    Date
    From: Kuniyuki Iwashima <kuniyu@amazon.com>

    [ Upstream commit 021266ec640c7a4527e6cd4b7349a512b351de1d ]

    While reading sysctl_tcp_fastopen_blackhole_timeout, it can be changed
    concurrently. Thus, we need to add READ_ONCE() to its readers.

    Fixes: cf1ef3f0719b ("net/tcp_fastopen: Disable active side TFO in certain scenarios")
    Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
    Signed-off-by: David S. Miller <davem@davemloft.net>
    Signed-off-by: Sasha Levin <sashal@kernel.org>
    ---
    net/ipv4/tcp_fastopen.c | 5 +++--
    1 file changed, 3 insertions(+), 2 deletions(-)

    diff --git a/net/ipv4/tcp_fastopen.c b/net/ipv4/tcp_fastopen.c
    index 936544a4753e..6e0a8ef5e816 100644
    --- a/net/ipv4/tcp_fastopen.c
    +++ b/net/ipv4/tcp_fastopen.c
    @@ -495,7 +495,7 @@ void tcp_fastopen_active_disable(struct sock *sk)
    {
    struct net *net = sock_net(sk);

    - if (!sock_net(sk)->ipv4.sysctl_tcp_fastopen_blackhole_timeout)
    + if (!READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_fastopen_blackhole_timeout))
    return;

    /* Paired with READ_ONCE() in tcp_fastopen_active_should_disable() */
    @@ -516,7 +516,8 @@ void tcp_fastopen_active_disable(struct sock *sk)
    */
    bool tcp_fastopen_active_should_disable(struct sock *sk)
    {
    - unsigned int tfo_bh_timeout = sock_net(sk)->ipv4.sysctl_tcp_fastopen_blackhole_timeout;
    + unsigned int tfo_bh_timeout =
    + READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_fastopen_blackhole_timeout);
    unsigned long timeout;
    int tfo_da_times;
    int multiplier;
    --
    2.35.1


    \
     
     \ /
      Last update: 2022-07-27 19:12    [W:4.158 / U:0.180 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site