From mboxrd@z Thu Jan 1 00:00:00 1970 From: Neal Cardwell Subject: [PATCH net 3/3] inet_diag: avoid unsafe and nonsensical prefix matches in inet_diag_bc_run() Date: Sun, 9 Dec 2012 00:43:23 -0500 Message-ID: <1355031803-14547-3-git-send-email-ncardwell@google.com> References: <1355031803-14547-1-git-send-email-ncardwell@google.com> Cc: edumazet@google.com, netdev@vger.kernel.org, Neal Cardwell To: David Miller Return-path: Received: from mail-bk0-f74.google.com ([209.85.214.74]:39495 "EHLO mail-bk0-f74.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756506Ab2LIFnb (ORCPT ); Sun, 9 Dec 2012 00:43:31 -0500 Received: by mail-bk0-f74.google.com with SMTP id je9so107127bkc.1 for ; Sat, 08 Dec 2012 21:43:31 -0800 (PST) In-Reply-To: <1355031803-14547-1-git-send-email-ncardwell@google.com> Sender: netdev-owner@vger.kernel.org List-ID: Add logic to check the address family of the user-supplied conditional and the address family of the connection entry. We now do not do prefix matching of addresses from different address families (AF_INET vs AF_INET6), except for the previously existing support for having an IPv4 prefix match an IPv4-mapped IPv6 address (which this commit maintains as-is). This change is needed for two reasons: (1) The addresses are different lengths, so comparing a 128-bit IPv6 prefix match condition to a 32-bit IPv4 connection address can cause us to unwittingly walk off the end of the IPv4 address and read garbage or oops. (2) The IPv4 and IPv6 address spaces are semantically distinct, so a simple bit-wise comparison of the prefixes is not meaningful, and would lead to bogus results (except for the IPv4-mapped IPv6 case, which this commit maintains). Signed-off-by: Neal Cardwell --- net/ipv4/inet_diag.c | 28 +++++++++++++++++----------- 1 files changed, 17 insertions(+), 11 deletions(-) diff --git a/net/ipv4/inet_diag.c b/net/ipv4/inet_diag.c index 529747d..95f1a45 100644 --- a/net/ipv4/inet_diag.c +++ b/net/ipv4/inet_diag.c @@ -432,25 +432,31 @@ static int inet_diag_bc_run(const struct nlattr *_bc, break; } - if (cond->prefix_len == 0) - break; - if (op->code == INET_DIAG_BC_S_COND) addr = entry->saddr; else addr = entry->daddr; + if (cond->family != AF_UNSPEC && + cond->family != entry->family) { + if (entry->family == AF_INET6 && + cond->family == AF_INET) { + if (addr[0] == 0 && addr[1] == 0 && + addr[2] == htonl(0xffff) && + bitstring_match(addr + 3, + cond->addr, + cond->prefix_len)) + break; + } + yes = 0; + break; + } + + if (cond->prefix_len == 0) + break; if (bitstring_match(addr, cond->addr, cond->prefix_len)) break; - if (entry->family == AF_INET6 && - cond->family == AF_INET) { - if (addr[0] == 0 && addr[1] == 0 && - addr[2] == htonl(0xffff) && - bitstring_match(addr + 3, cond->addr, - cond->prefix_len)) - break; - } yes = 0; break; } -- 1.7.7.3