diff options
| author | Kuniyuki Iwashima <kuniyu@amazon.com> | 2024-04-30 04:58:08 +0300 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2024-05-02 04:37:06 +0300 |
| commit | 0592367424bbbdef506ef1450f5b8beec148f8a4 (patch) | |
| tree | 5de93458ff802e85bcdbddcef58c5547d27a9ff4 /net | |
| parent | 42033d0cfc8606adc9cb7e18d4c73d2e9a6289e5 (diff) | |
| download | linux-0592367424bbbdef506ef1450f5b8beec148f8a4.tar.xz | |
arp: Validate netmask earlier for SIOCDARP and SIOCSARP in arp_ioctl().
When ioctl(SIOCDARP/SIOCSARP) is issued with ATF_PUBL, r.arp_netmask
must be 0.0.0.0 or 255.255.255.255.
Currently, the netmask is validated in arp_req_delete_public() or
arp_req_set_public() under rtnl_lock().
We have ATF_NETMASK test in arp_ioctl() before holding rtnl_lock(),
so let's move the netmask validation there.
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20240430015813.71143-3-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/ipv4/arp.c | 27 |
1 files changed, 15 insertions, 12 deletions
diff --git a/net/ipv4/arp.c b/net/ipv4/arp.c index 3093374165fa..b20a5771d069 100644 --- a/net/ipv4/arp.c +++ b/net/ipv4/arp.c @@ -1023,11 +1023,8 @@ static int arp_req_set_proxy(struct net *net, struct net_device *dev, int on) static int arp_req_set_public(struct net *net, struct arpreq *r, struct net_device *dev) { - __be32 ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr; __be32 mask = ((struct sockaddr_in *)&r->arp_netmask)->sin_addr.s_addr; - if (mask && mask != htonl(0xFFFFFFFF)) - return -EINVAL; if (!dev && (r->arp_flags & ATF_COM)) { dev = dev_getbyhwaddr_rcu(net, r->arp_ha.sa_family, r->arp_ha.sa_data); @@ -1035,6 +1032,8 @@ static int arp_req_set_public(struct net *net, struct arpreq *r, return -ENODEV; } if (mask) { + __be32 ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr; + if (!pneigh_lookup(&arp_tbl, net, &ip, dev, 1)) return -ENOBUFS; return 0; @@ -1171,14 +1170,13 @@ int arp_invalidate(struct net_device *dev, __be32 ip, bool force) static int arp_req_delete_public(struct net *net, struct arpreq *r, struct net_device *dev) { - __be32 ip = ((struct sockaddr_in *) &r->arp_pa)->sin_addr.s_addr; __be32 mask = ((struct sockaddr_in *)&r->arp_netmask)->sin_addr.s_addr; - if (mask == htonl(0xFFFFFFFF)) - return pneigh_delete(&arp_tbl, net, &ip, dev); + if (mask) { + __be32 ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr; - if (mask) - return -EINVAL; + return pneigh_delete(&arp_tbl, net, &ip, dev); + } return arp_req_set_proxy(net, dev, 0); } @@ -1211,9 +1209,10 @@ static int arp_req_delete(struct net *net, struct arpreq *r, int arp_ioctl(struct net *net, unsigned int cmd, void __user *arg) { - int err; - struct arpreq r; struct net_device *dev = NULL; + struct arpreq r; + __be32 *netmask; + int err; switch (cmd) { case SIOCDARP: @@ -1236,9 +1235,13 @@ int arp_ioctl(struct net *net, unsigned int cmd, void __user *arg) if (!(r.arp_flags & ATF_PUBL) && (r.arp_flags & (ATF_NETMASK | ATF_DONTPUB))) return -EINVAL; + + netmask = &((struct sockaddr_in *)&r.arp_netmask)->sin_addr.s_addr; if (!(r.arp_flags & ATF_NETMASK)) - ((struct sockaddr_in *)&r.arp_netmask)->sin_addr.s_addr = - htonl(0xFFFFFFFFUL); + *netmask = htonl(0xFFFFFFFFUL); + else if (*netmask && *netmask != htonl(0xFFFFFFFFUL)) + return -EINVAL; + rtnl_lock(); if (r.arp_dev[0]) { err = -ENODEV; |