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authorKuniyuki Iwashima <kuniyu@amazon.com>2022-07-12 03:15:32 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2022-07-21 22:20:10 +0300
commit2c56958de89b9a2efdb19310e3f11a6b97254d39 (patch)
treea79b2adc016487f6616fd2b742aa19cb41cec1f7
parent038a87b3e460d2ee579c8b1bd3890d816d6687b1 (diff)
downloadlinux-2c56958de89b9a2efdb19310e3f11a6b97254d39.tar.xz
ipv4: Fix data-races around sysctl_ip_dynaddr.
[ Upstream commit e49e4aff7ec19b2d0d0957ee30e93dade57dab9e ] 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 <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
-rw-r--r--Documentation/networking/ip-sysctl.rst2
-rw-r--r--net/ipv4/af_inet.c4
2 files changed, 3 insertions, 3 deletions
diff --git a/Documentation/networking/ip-sysctl.rst b/Documentation/networking/ip-sysctl.rst
index 73de75906b24..0b1f3235aa77 100644
--- a/Documentation/networking/ip-sysctl.rst
+++ b/Documentation/networking/ip-sysctl.rst
@@ -1080,7 +1080,7 @@ 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 742218594741..e77283069c7b 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -1245,7 +1245,7 @@ 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);
}
@@ -1300,7 +1300,7 @@ 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)