From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-Id: <20120607041402.488333447@linuxfoundation.org> Date: Thu, 07 Jun 2012 13:14:28 +0900 From: Greg KH To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Yevgen Pronenko , "David S. Miller" Subject: [ 30/47] ipv4: Do not use dead fib_info entries. In-Reply-To: <20120607041504.GA13819@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.0-stable review patch. If anyone has any objections, please let me know. ------------------ From: "David S. Miller" [ Upstream commit dccd9ecc374462e5d6a5b8f8110415a86c2213d8 ] Due to RCU lookups and RCU based release, fib_info objects can be found during lookup which have fi->fib_dead set. We must ignore these entries, otherwise we risk dereferencing the parts of the entry which are being torn down. Reported-by: Yevgen Pronenko Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv4/fib_trie.c | 2 ++ 1 file changed, 2 insertions(+) --- a/net/ipv4/fib_trie.c +++ b/net/ipv4/fib_trie.c @@ -1371,6 +1371,8 @@ static int check_leaf(struct fib_table * if (fa->fa_tos && fa->fa_tos != flp->flowi4_tos) continue; + if (fi->fib_dead) + continue; if (fa->fa_info->fib_scope < flp->flowi4_scope) continue; fib_alias_accessed(fa);