From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4BDC4C7EE32 for ; Fri, 3 Mar 2023 21:49:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232757AbjCCVtm (ORCPT ); Fri, 3 Mar 2023 16:49:42 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37772 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232753AbjCCVtE (ORCPT ); Fri, 3 Mar 2023 16:49:04 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E2F616703F; Fri, 3 Mar 2023 13:45:44 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id ECFD2B81A09; Fri, 3 Mar 2023 21:45:23 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 59B91C4339B; Fri, 3 Mar 2023 21:45:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1677879922; bh=08JKqLomuqR8Z+WnXh9Rr9/MR0OoAsnToT9vuZiLzkg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mspy/E0ZzxK617jzB3y9Q9XOJS/zR5ao67YYwjTkdbAxxhh4+4pVtf+6QuedYcJ0S 3rNbviRNCn6YDg1NkO2ynqzz21tpCeWa9Sqr6mpQWxta/AnfxMiTTsNWUHv82qHIFg Y6tP8bblA8XSQ8QHSgDE6XuzmMcOCDEhh7sPWymGovGzBjGuts2ZBkgUSxJmIYYhDA aJlDxFu3EeO9jSMI6BeEVoraPn8tYV6tHviz4kbvnw+sk/x8IrjtjRVC1hoyRXif5U Cg7Eom6KRU1F4Fv1XFlW9N+/1qF8l7BKJxFvWYPxOSXtLkwORXEok+iXGEP85TyAWB y3Q17anNDHhKw== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Kees Cook , Nathan Chancellor , Jason Gunthorpe , Sasha Levin , ndesaulniers@google.com, markzhang@nvidia.com, Jason@zx2c4.com, phaddad@nvidia.com, haakon.bugge@oracle.com, linux-rdma@vger.kernel.org, llvm@lists.linux.dev Subject: [PATCH AUTOSEL 6.1 57/60] RDMA/cma: Distinguish between sockaddr_in and sockaddr_in6 by size Date: Fri, 3 Mar 2023 16:43:11 -0500 Message-Id: <20230303214315.1447666-57-sashal@kernel.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230303214315.1447666-1-sashal@kernel.org> References: <20230303214315.1447666-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Kees Cook [ Upstream commit 876e480da2f74715fc70e37723e77ca16a631e35 ] Clang can do some aggressive inlining, which provides it with greater visibility into the sizes of various objects that are passed into helpers. Specifically, compare_netdev_and_ip() can see through the type given to the "sa" argument, which means it can generate code for "struct sockaddr_in" that would have been passed to ipv6_addr_cmp() (that expects to operate on the larger "struct sockaddr_in6"), which would result in a compile-time buffer overflow condition detected by memcmp(). Logically, this state isn't reachable due to the sa_family assignment two callers above and the check in compare_netdev_and_ip(). Instead, provide a compile-time check on sizes so the size-mismatched code will be elided when inlining. Avoids the following warning from Clang: ../include/linux/fortify-string.h:652:4: error: call to '__read_overflow' declared with 'error' attribute: detected read beyond size of object (1st parameter) __read_overflow(); ^ note: In function 'cma_netevent_callback' note: which inlined function 'node_from_ndev_ip' 1 error generated. When the underlying object size is not known (e.g. with GCC and older Clang), the result of __builtin_object_size() is SIZE_MAX, which will also compile away, leaving the code as it was originally. Link: https://lore.kernel.org/r/20230208232549.never.139-kees@kernel.org Link: https://github.com/ClangBuiltLinux/linux/issues/1687 Signed-off-by: Kees Cook Tested-by: Nathan Chancellor # build Signed-off-by: Jason Gunthorpe Signed-off-by: Sasha Levin --- drivers/infiniband/core/cma.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c index 26d1772179b8f..8730674ceb2e1 100644 --- a/drivers/infiniband/core/cma.c +++ b/drivers/infiniband/core/cma.c @@ -479,13 +479,20 @@ static int compare_netdev_and_ip(int ifindex_a, struct sockaddr *sa, if (sa->sa_family != sb->sa_family) return sa->sa_family - sb->sa_family; - if (sa->sa_family == AF_INET) - return memcmp((char *)&((struct sockaddr_in *)sa)->sin_addr, - (char *)&((struct sockaddr_in *)sb)->sin_addr, + if (sa->sa_family == AF_INET && + __builtin_object_size(sa, 0) >= sizeof(struct sockaddr_in)) { + return memcmp(&((struct sockaddr_in *)sa)->sin_addr, + &((struct sockaddr_in *)sb)->sin_addr, sizeof(((struct sockaddr_in *)sa)->sin_addr)); + } + + if (sa->sa_family == AF_INET6 && + __builtin_object_size(sa, 0) >= sizeof(struct sockaddr_in6)) { + return ipv6_addr_cmp(&((struct sockaddr_in6 *)sa)->sin6_addr, + &((struct sockaddr_in6 *)sb)->sin6_addr); + } - return ipv6_addr_cmp(&((struct sockaddr_in6 *)sa)->sin6_addr, - &((struct sockaddr_in6 *)sb)->sin6_addr); + return -1; } static int cma_add_id_to_tree(struct rdma_id_private *node_id_priv) -- 2.39.2