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authorKuniyuki Iwashima <kuniyu@amazon.com>2022-07-18 20:26:42 +0300
committerDavid S. Miller <davem@davemloft.net>2022-07-20 12:14:49 +0300
commit9b55c20f83369dd54541d9ddbe3a018a8377f451 (patch)
tree47fb5876d7c291eda26016d3711002bfb19f9bf4
parent8895a9c2ac76fb9d3922fed4fe092c8ec5e5cccc (diff)
downloadlinux-9b55c20f83369dd54541d9ddbe3a018a8377f451.tar.xz
ip: Fix data-races around sysctl_ip_prot_sock.
sysctl_ip_prot_sock is accessed concurrently, and there is always a chance of data-race. So, all readers and writers need some basic protection to avoid load/store-tearing. Fixes: 4548b683b781 ("Introduce a sysctl that modifies the value of PROT_SOCK.") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--include/net/ip.h2
-rw-r--r--net/ipv4/sysctl_net_ipv4.c6
2 files changed, 4 insertions, 4 deletions
diff --git a/include/net/ip.h b/include/net/ip.h
index 4a15b6bcb4b8..1c979fd1904c 100644
--- a/include/net/ip.h
+++ b/include/net/ip.h
@@ -357,7 +357,7 @@ static inline bool sysctl_dev_name_is_allowed(const char *name)
static inline bool inet_port_requires_bind_service(struct net *net, unsigned short port)
{
- return port < net->ipv4.sysctl_ip_prot_sock;
+ return port < READ_ONCE(net->ipv4.sysctl_ip_prot_sock);
}
#else
diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c
index 130e9c130311..5490c285668b 100644
--- a/net/ipv4/sysctl_net_ipv4.c
+++ b/net/ipv4/sysctl_net_ipv4.c
@@ -84,7 +84,7 @@ static int ipv4_local_port_range(struct ctl_table *table, int write,
* port limit.
*/
if ((range[1] < range[0]) ||
- (range[0] < net->ipv4.sysctl_ip_prot_sock))
+ (range[0] < READ_ONCE(net->ipv4.sysctl_ip_prot_sock)))
ret = -EINVAL;
else
set_local_port_range(net, range);
@@ -110,7 +110,7 @@ static int ipv4_privileged_ports(struct ctl_table *table, int write,
.extra2 = &ip_privileged_port_max,
};
- pports = net->ipv4.sysctl_ip_prot_sock;
+ pports = READ_ONCE(net->ipv4.sysctl_ip_prot_sock);
ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
@@ -122,7 +122,7 @@ static int ipv4_privileged_ports(struct ctl_table *table, int write,
if (range[0] < pports)
ret = -EINVAL;
else
- net->ipv4.sysctl_ip_prot_sock = pports;
+ WRITE_ONCE(net->ipv4.sysctl_ip_prot_sock, pports);
}
return ret;