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| author | Felix Jia <felix.jia@alliedtelesis.co.nz> | 2017-02-27 00:41:23 +0100 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-03-01 19:22:48 +0100 |
| commit | 8c171d6ca56c6891372a97af26b58b2cfad7fd9a (patch) | |
| tree | 13aaa3cbaebb1e12014a986f9f5e2c7c944501b1 | |
| parent | Merge branch 'vxlan-geneve-rcu-fixes' (diff) | |
| download | linux-8c171d6ca56c6891372a97af26b58b2cfad7fd9a.tar.xz linux-8c171d6ca56c6891372a97af26b58b2cfad7fd9a.zip | |
net/ipv6: avoid possible dead locking on addr_gen_mode sysctl
The addr_gen_mode variable can be accessed by both sysctl and netlink.
Repleacd rtnl_lock() with rtnl_trylock() protect the sysctl operation to
avoid the possbile dead lock.`
Signed-off-by: Felix Jia <felix.jia@alliedtelesis.co.nz>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/ipv6/addrconf.c | 22 |
1 files changed, 15 insertions, 7 deletions
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index 3a2025f5bf2c..cfc485a8e1c0 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -5692,13 +5692,18 @@ static int addrconf_sysctl_addr_gen_mode(struct ctl_table *ctl, int write, struct inet6_dev *idev = (struct inet6_dev *)ctl->extra1; struct net *net = (struct net *)ctl->extra2; + if (!rtnl_trylock()) + return restart_syscall(); + ret = proc_dointvec(ctl, write, buffer, lenp, ppos); if (write) { new_val = *((int *)ctl->data); - if (check_addr_gen_mode(new_val) < 0) - return -EINVAL; + if (check_addr_gen_mode(new_val) < 0) { + ret = -EINVAL; + goto out; + } /* request for default */ if (&net->ipv6.devconf_dflt->addr_gen_mode == ctl->data) { @@ -5707,20 +5712,23 @@ static int addrconf_sysctl_addr_gen_mode(struct ctl_table *ctl, int write, /* request for individual net device */ } else { if (!idev) - return ret; + goto out; - if (check_stable_privacy(idev, net, new_val) < 0) - return -EINVAL; + if (check_stable_privacy(idev, net, new_val) < 0) { + ret = -EINVAL; + goto out; + } if (idev->cnf.addr_gen_mode != new_val) { idev->cnf.addr_gen_mode = new_val; - rtnl_lock(); addrconf_dev_config(idev->dev); - rtnl_unlock(); } } } +out: + rtnl_unlock(); + return ret; } |