From: Jason Xing <kernelxing@xxxxxxxxxxx>
[ Upstream commit 119cae5ea3f9e35cdada8e572cc067f072fa825a ]
We need to protect the reader reading the sysctl value because the
value can be changed concurrently.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Jason Xing <kernelxing@xxxxxxxxxxx>
Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
net/netrom/nr_dev.c | 2 +-
net/netrom/nr_out.c | 2 +-
net/netrom/nr_subr.c | 5 +++--
3 files changed, 5 insertions(+), 4 deletions(-)
diff --git a/net/netrom/nr_dev.c b/net/netrom/nr_dev.c
index 988f542481a83..fa845edad7bf6 100644
--- a/net/netrom/nr_dev.c
+++ b/net/netrom/nr_dev.c
@@ -84,7 +84,7 @@ static int nr_header(struct sk_buff *skb, struct net_device *dev,
buff[6] |= AX25_SSSID_SPARE;
buff += AX25_ADDR_LEN;
- *buff++ = sysctl_netrom_network_ttl_initialiser;
+ *buff++ = READ_ONCE(sysctl_netrom_network_ttl_initialiser);
*buff++ = NR_PROTO_IP;
*buff++ = NR_PROTO_IP;
diff --git a/net/netrom/nr_out.c b/net/netrom/nr_out.c
index 00fbf1419ec6b..213bddab6e74f 100644
--- a/net/netrom/nr_out.c
+++ b/net/netrom/nr_out.c
@@ -207,7 +207,7 @@ void nr_transmit_buffer(struct sock *sk, struct sk_buff *skb)
dptr[6] |= AX25_SSSID_SPARE;
dptr += AX25_ADDR_LEN;
- *dptr++ = sysctl_netrom_network_ttl_initialiser;
+ *dptr++ = READ_ONCE(sysctl_netrom_network_ttl_initialiser);
if (!nr_route_frame(skb, NULL)) {
kfree_skb(skb);
diff --git a/net/netrom/nr_subr.c b/net/netrom/nr_subr.c
index a7d3a265befb9..b5cee72b8c985 100644
--- a/net/netrom/nr_subr.c
+++ b/net/netrom/nr_subr.c
@@ -185,7 +185,8 @@ void nr_write_internal(struct sock *sk, int frametype)
*dptr++ = nr->my_id;
*dptr++ = frametype;
*dptr++ = nr->window;
- if (nr->bpqext) *dptr++ = sysctl_netrom_network_ttl_initialiser;
+ if (nr->bpqext)
+ *dptr++ = READ_ONCE(sysctl_netrom_network_ttl_initialiser);
break;
case NR_DISCREQ:
@@ -239,7 +240,7 @@ void __nr_transmit_reply(struct sk_buff *skb, int mine, unsigned char cmdflags)
dptr[6] |= AX25_SSSID_SPARE;
dptr += AX25_ADDR_LEN;
- *dptr++ = sysctl_netrom_network_ttl_initialiser;
+ *dptr++ = READ_ONCE(sysctl_netrom_network_ttl_initialiser);
if (mine) {
*dptr++ = 0;
--
2.43.0
