netrom: Fix data-races around sysctl_netrom_network_ttl_initialiser

We need to protect the reader reading the sysctl value because the
value can be changed concurrently.

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Jason Xing <kernelxing@tencent.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
This commit is contained in:
Jason Xing 2024-03-04 16:20:37 +08:00 committed by Paolo Abeni
parent cfd9f4a740
commit 119cae5ea3
3 changed files with 5 additions and 4 deletions

View File

@ -81,7 +81,7 @@ 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;

View File

@ -204,7 +204,7 @@ 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);

View File

@ -182,7 +182,8 @@ 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:
@ -236,7 +237,7 @@ 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;