svcrpc: fix rare race on unix_domain creation

Note that "new" here is not yet fully initialized; auth_domain_put
should be called only on auth_domains that have actually been added to
the hash.

Before this fix, two attempts to add the same domain at once could
cause the hlist_del in auth_domain_put to fail.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
This commit is contained in:
J. Bruce Fields 2011-03-07 22:50:47 -05:00
parent 5ece3cafbd
commit 8b3e07ac90

View file

@ -38,6 +38,14 @@ struct unix_domain {
extern struct auth_ops svcauth_unix;
static void svcauth_unix_domain_release(struct auth_domain *dom)
{
struct unix_domain *ud = container_of(dom, struct unix_domain, h);
kfree(dom->name);
kfree(ud);
}
struct auth_domain *unix_domain_find(char *name)
{
struct auth_domain *rv;
@ -47,7 +55,7 @@ struct auth_domain *unix_domain_find(char *name)
while(1) {
if (rv) {
if (new && rv != &new->h)
auth_domain_put(&new->h);
svcauth_unix_domain_release(new);
if (rv->flavour != &svcauth_unix) {
auth_domain_put(rv);
@ -74,14 +82,6 @@ struct auth_domain *unix_domain_find(char *name)
}
EXPORT_SYMBOL_GPL(unix_domain_find);
static void svcauth_unix_domain_release(struct auth_domain *dom)
{
struct unix_domain *ud = container_of(dom, struct unix_domain, h);
kfree(dom->name);
kfree(ud);
}
/**************************************************
* cache for IP address to unix_domain