On Mon, Nov 2, 2015 at 1:31 PM, Cong Wang <cw...@twopensource.com> wrote:
>
> Good catch!
>
> This is probably introduced by:
>
> commit baf606d9c9b12517e47e0d1370e8aa9f7323f210
> Author: Marcelo Ricardo Leitner <marcelo.leit...@gmail.com>
> Date: Wed Mar 18 14:50:42 2015 -0300
>
> ipv4,ipv6: grab rtnl before locking the socket
>
> I am thinking what is the right way to fix it...
Please try the attached patch.
Thanks!
diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c
index d38b8b6..a2429b7 100644
--- a/net/ipv4/igmp.c
+++ b/net/ipv4/igmp.c
@@ -2392,11 +2392,11 @@ int ip_mc_msfget(struct sock *sk, struct ip_msfilter *msf,
struct ip_sf_socklist *psl;
struct net *net = sock_net(sk);
+ ASSERT_RTNL();
+
if (!ipv4_is_multicast(addr))
return -EINVAL;
- rtnl_lock();
-
imr.imr_multiaddr.s_addr = msf->imsf_multiaddr;
imr.imr_address.s_addr = msf->imsf_interface;
imr.imr_ifindex = 0;
@@ -2417,7 +2417,6 @@ int ip_mc_msfget(struct sock *sk, struct ip_msfilter *msf,
goto done;
msf->imsf_fmode = pmc->sfmode;
psl = rtnl_dereference(pmc->sflist);
- rtnl_unlock();
if (!psl) {
len = 0;
count = 0;
@@ -2436,7 +2435,6 @@ int ip_mc_msfget(struct sock *sk, struct ip_msfilter *msf,
return -EFAULT;
return 0;
done:
- rtnl_unlock();
return err;
}
@@ -2450,6 +2448,8 @@ int ip_mc_gsfget(struct sock *sk, struct group_filter *gsf,
struct inet_sock *inet = inet_sk(sk);
struct ip_sf_socklist *psl;
+ ASSERT_RTNL();
+
psin = (struct sockaddr_in *)&gsf->gf_group;
if (psin->sin_family != AF_INET)
return -EINVAL;
@@ -2457,8 +2457,6 @@ int ip_mc_gsfget(struct sock *sk, struct group_filter *gsf,
if (!ipv4_is_multicast(addr))
return -EINVAL;
- rtnl_lock();
-
err = -EADDRNOTAVAIL;
for_each_pmc_rtnl(inet, pmc) {
@@ -2470,7 +2468,6 @@ int ip_mc_gsfget(struct sock *sk, struct group_filter *gsf,
goto done;
gsf->gf_fmode = pmc->sfmode;
psl = rtnl_dereference(pmc->sflist);
- rtnl_unlock();
count = psl ? psl->sl_count : 0;
copycount = count < gsf->gf_numsrc ? count : gsf->gf_numsrc;
gsf->gf_numsrc = count;
@@ -2490,7 +2487,6 @@ int ip_mc_gsfget(struct sock *sk, struct group_filter *gsf,
}
return 0;
done:
- rtnl_unlock();
return err;
}
diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index c3c359a..2b12ed2 100644
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -1251,11 +1251,22 @@ EXPORT_SYMBOL(compat_ip_setsockopt);
* the _received_ ones. The set sets the _sent_ ones.
*/
+static bool getsockopt_needs_rtnl(int optname)
+{
+ switch (optname) {
+ case IP_MSFILTER:
+ case MCAST_MSFILTER:
+ return true;
+ }
+ return false;
+}
+
static int do_ip_getsockopt(struct sock *sk, int level, int optname,
char __user *optval, int __user *optlen, unsigned int flags)
{
struct inet_sock *inet = inet_sk(sk);
- int val;
+ bool needs_rtnl = getsockopt_needs_rtnl(optname);
+ int val, err;
int len;
if (level != SOL_IP)
@@ -1269,6 +1280,8 @@ static int do_ip_getsockopt(struct sock *sk, int level, int optname,
if (len < 0)
return -EINVAL;
+ if (needs_rtnl)
+ rtnl_lock();
lock_sock(sk);
switch (optname) {
@@ -1389,17 +1402,16 @@ static int do_ip_getsockopt(struct sock *sk, int level, int optname,
int err;
if (len < IP_MSFILTER_SIZE(0)) {
- release_sock(sk);
- return -EINVAL;
+ err = -EINVAL;
+ goto out;
}
if (copy_from_user(&msf, optval, IP_MSFILTER_SIZE(0))) {
- release_sock(sk);
- return -EFAULT;
+ err = -EFAULT;
+ goto out;
}
err = ip_mc_msfget(sk, &msf,
(struct ip_msfilter __user *)optval, optlen);
- release_sock(sk);
- return err;
+ goto out;
}
case MCAST_MSFILTER:
{
@@ -1407,18 +1419,17 @@ static int do_ip_getsockopt(struct sock *sk, int level, int optname,
int err;
if (len < GROUP_FILTER_SIZE(0)) {
- release_sock(sk);
- return -EINVAL;
+ err = -EINVAL;
+ goto out;
}
if (copy_from_user(&gsf, optval, GROUP_FILTER_SIZE(0))) {
- release_sock(sk);
- return -EFAULT;
+ err = -EFAULT;
+ goto out;
}
err = ip_mc_gsfget(sk, &gsf,
(struct group_filter __user *)optval,
optlen);
- release_sock(sk);
- return err;
+ goto out;
}
case IP_MULTICAST_ALL:
val = inet->mc_all;
@@ -1485,6 +1496,12 @@ static int do_ip_getsockopt(struct sock *sk, int level, int optname,
return -EFAULT;
}
return 0;
+
+out:
+ release_sock(sk);
+ if (needs_rtnl)
+ rtnl_unlock();
+ return err;
}
int ip_getsockopt(struct sock *sk, int level,
