| Message ID | m14o6wjhm5.fsf@fess.ebiederm.org |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
From: ebiederm@xmission.com (Eric W. Biederman) Date: Mon, 21 Mar 2011 14:20:18 -0700 > > When I was fixing issues with unregisgtering tables under /proc/sys/net/ipv6/neigh > by adding a mount point it appears I missed a critical ordering issue, in the > ipv6 initialization. I had not realized that ipv6_sysctl_register is called > at the very end of the ipv6 initialization and in particular after we call > neigh_sysctl_register from ndisc_init. > > "neigh" needs to be initialized in ipv6_static_sysctl_register which is > the first ipv6 table to initialized, and definitely before ndisc_init. > This removes the weirdness of duplicate tables while still providing a > "neigh" mount point which prevents races in sysctl unregistering. > > This was initially reported at https://bugzilla.kernel.org/show_bug.cgi?id=31232 > Reported-by: sunkan@zappa.cx > Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com> Applied, thanks. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/net/ipv6/sysctl_net_ipv6.c b/net/ipv6/sysctl_net_ipv6.c index 7cb65ef..6dcf5e7 100644 --- a/net/ipv6/sysctl_net_ipv6.c +++ b/net/ipv6/sysctl_net_ipv6.c @@ -17,6 +17,16 @@ static struct ctl_table empty[1]; +static ctl_table ipv6_static_skeleton[] = { + { + .procname = "neigh", + .maxlen = 0, + .mode = 0555, + .child = empty, + }, + { } +}; + static ctl_table ipv6_table_template[] = { { .procname = "route", @@ -37,12 +47,6 @@ static ctl_table ipv6_table_template[] = { .mode = 0644, .proc_handler = proc_dointvec }, - { - .procname = "neigh", - .maxlen = 0, - .mode = 0555, - .child = empty, - }, { } }; @@ -160,7 +164,7 @@ static struct ctl_table_header *ip6_base; int ipv6_static_sysctl_register(void) { - ip6_base = register_sysctl_paths(net_ipv6_ctl_path, empty); + ip6_base = register_sysctl_paths(net_ipv6_ctl_path, ipv6_static_skeleton); if (ip6_base == NULL) return -ENOMEM; return 0;
When I was fixing issues with unregisgtering tables under /proc/sys/net/ipv6/neigh by adding a mount point it appears I missed a critical ordering issue, in the ipv6 initialization. I had not realized that ipv6_sysctl_register is called at the very end of the ipv6 initialization and in particular after we call neigh_sysctl_register from ndisc_init. "neigh" needs to be initialized in ipv6_static_sysctl_register which is the first ipv6 table to initialized, and definitely before ndisc_init. This removes the weirdness of duplicate tables while still providing a "neigh" mount point which prevents races in sysctl unregistering. This was initially reported at https://bugzilla.kernel.org/show_bug.cgi?id=31232 Reported-by: sunkan@zappa.cx Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com> --- net/ipv6/sysctl_net_ipv6.c | 18 +++++++++++------- 1 files changed, 11 insertions(+), 7 deletions(-)