| Message ID | m1ehumc8r4.fsf_-_@fess.ebiederm.org |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
From: ebiederm@xmission.com (Eric W. Biederman) Date: Thu, 26 Jan 2012 16:02:55 -0800 > By definition net_generic should never be called when it can return > NULL. Fail conspicously with a BUG_ON to make it clear when people mess > up that a NULL return should never happen. > > Recently there was a bug in the CAIF subsystem where it was registered > with register_pernet_device instead of register_pernet_subsys. It was > erroneously concluded that net_generic could validly return NULL and > that net_assign_generic was buggy (when it was just inefficient). > Hopefully this BUG_ON will prevent people to coming to similar erroneous > conclusions in the futrue. > > Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Applied. -- 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/include/net/netns/generic.h b/include/net/netns/generic.h index 3419bf5..d55f434 100644 --- a/include/net/netns/generic.h +++ b/include/net/netns/generic.h @@ -41,6 +41,7 @@ static inline void *net_generic(const struct net *net, int id) ptr = ng->ptr[id - 1]; rcu_read_unlock(); + BUG_ON(!ptr); return ptr; } #endif
By definition net_generic should never be called when it can return NULL. Fail conspicously with a BUG_ON to make it clear when people mess up that a NULL return should never happen. Recently there was a bug in the CAIF subsystem where it was registered with register_pernet_device instead of register_pernet_subsys. It was erroneously concluded that net_generic could validly return NULL and that net_assign_generic was buggy (when it was just inefficient). Hopefully this BUG_ON will prevent people to coming to similar erroneous conclusions in the futrue. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> --- include/net/netns/generic.h | 1 + 1 files changed, 1 insertions(+), 0 deletions(-)