From: Kuniyuki Iwashima Date: Tue, 12 Jul 2022 00:15:32 +0000 (-0700) Subject: ipv4: Fix data-races around sysctl_ip_dynaddr. X-Git-Tag: baikal/mips/sdk6.1~5324^2~17^2~1 X-Git-Url: https://git.baikalelectronics.ru/?a=commitdiff_plain;h=6ec8b4da081476c48417184be7a220690623396f;p=kernel.git ipv4: Fix data-races around sysctl_ip_dynaddr. While reading sysctl_ip_dynaddr, it can be changed concurrently. Thus, we need to add READ_ONCE() to its readers. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima Signed-off-by: David S. Miller --- diff --git a/Documentation/networking/ip-sysctl.rst b/Documentation/networking/ip-sysctl.rst index 0e58001f85803..b3a534ed0e7c5 100644 --- a/Documentation/networking/ip-sysctl.rst +++ b/Documentation/networking/ip-sysctl.rst @@ -1179,7 +1179,7 @@ ip_autobind_reuse - BOOLEAN option should only be set by experts. Default: 0 -ip_dynaddr - BOOLEAN +ip_dynaddr - INTEGER If set non-zero, enables support for dynamic addresses. If set to a non-zero value larger than 1, a kernel log message will be printed when dynamic address rewriting diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c index 93da9f783bec5..ac67f6b4ec700 100644 --- a/net/ipv4/af_inet.c +++ b/net/ipv4/af_inet.c @@ -1246,7 +1246,7 @@ static int inet_sk_reselect_saddr(struct sock *sk) if (new_saddr == old_saddr) return 0; - if (sock_net(sk)->ipv4.sysctl_ip_dynaddr > 1) { + if (READ_ONCE(sock_net(sk)->ipv4.sysctl_ip_dynaddr) > 1) { pr_info("%s(): shifting inet->saddr from %pI4 to %pI4\n", __func__, &old_saddr, &new_saddr); } @@ -1301,7 +1301,7 @@ int inet_sk_rebuild_header(struct sock *sk) * Other protocols have to map its equivalent state to TCP_SYN_SENT. * DCCP maps its DCCP_REQUESTING state to TCP_SYN_SENT. -acme */ - if (!sock_net(sk)->ipv4.sysctl_ip_dynaddr || + if (!READ_ONCE(sock_net(sk)->ipv4.sysctl_ip_dynaddr) || sk->sk_state != TCP_SYN_SENT || (sk->sk_userlocks & SOCK_BINDADDR_LOCK) || (err = inet_sk_reselect_saddr(sk)) != 0)