net: use hlist_del_rcu() in dev_change_name()

BugLink: http://bugs.launchpad.net/bugs/793702

[ Upstream commit 372b2312010bece1e36f577d6c99a6193ec54cbd ]

Using plain hlist_del() in dev_change_name() is wrong since a
concurrent reader can crash trying to dereference LIST_POISON1.

Bug introduced in commit 72c9528bab94 (net: Introduce
dev_get_by_name_rcu())

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>

diff --git a/net/core/dev.c b/net/core/dev.c
index af0995d..2bb4aa6 100644 (file)
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1006,7 +1006,7 @@ rollback:
        }
 
        write_lock_bh(&dev_base_lock);
-       hlist_del(&dev->name_hlist);
+       hlist_del_rcu(&dev->name_hlist);
        write_unlock_bh(&dev_base_lock);
 
        synchronize_rcu();