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 6025DC32774 for ; Tue, 23 Aug 2022 12:18:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1352392AbiHWMRt (ORCPT ); Tue, 23 Aug 2022 08:17:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50852 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240207AbiHWMO4 (ORCPT ); Tue, 23 Aug 2022 08:14:56 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 56B09E9916; Tue, 23 Aug 2022 02:40:50 -0700 (PDT) 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 30D86B81C89; Tue, 23 Aug 2022 09:39:53 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9567EC433C1; Tue, 23 Aug 2022 09:39:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1661247592; bh=xt9Z0x6wZKXP0XPQ3nzzHDOiKcMowZ34WYDeRTxaghc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=J5Ax7VMvDfscboRECK9UgNHRIP+i2Gx7e2XRysNogZTTOY5UvO0Ixad9uRiNkHjLU GnG/dkSABzf8EAhduBUny5iS8WikAwWYq4TgbWqLAugTVnPJflG4oeiUYH+OTUg9QW H3NxYh7DSzgmdQmzm8hM4xIIDYTWF/PgOZYZ1v+4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+dc54d9ba8153b216cae0@syzkaller.appspotmail.com, Jakub Kicinski Subject: [PATCH 5.10 084/158] net: genl: fix error path memory leak in policy dumping Date: Tue, 23 Aug 2022 10:26:56 +0200 Message-Id: <20220823080049.457436218@linuxfoundation.org> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220823080046.056825146@linuxfoundation.org> References: <20220823080046.056825146@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Jakub Kicinski commit 249801360db3dec4f73768c502192020bfddeacc upstream. If construction of the array of policies fails when recording non-first policy we need to unwind. netlink_policy_dump_add_policy() itself also needs fixing as it currently gives up on error without recording the allocated pointer in the pstate pointer. Reported-by: syzbot+dc54d9ba8153b216cae0@syzkaller.appspotmail.com Fixes: 50a896cf2d6f ("genetlink: properly support per-op policy dumping") Link: https://lore.kernel.org/r/20220816161939.577583-1-kuba@kernel.org Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- net/netlink/genetlink.c | 6 +++++- net/netlink/policy.c | 14 ++++++++++++-- 2 files changed, 17 insertions(+), 3 deletions(-) --- a/net/netlink/genetlink.c +++ b/net/netlink/genetlink.c @@ -1182,13 +1182,17 @@ static int ctrl_dumppolicy_start(struct op.policy, op.maxattr); if (err) - return err; + goto err_free_state; } } if (!ctx->state) return -ENODATA; return 0; + +err_free_state: + netlink_policy_dump_free(ctx->state); + return err; } static void *ctrl_dumppolicy_prep(struct sk_buff *skb, --- a/net/netlink/policy.c +++ b/net/netlink/policy.c @@ -144,7 +144,7 @@ int netlink_policy_dump_add_policy(struc err = add_policy(&state, policy, maxtype); if (err) - return err; + goto err_try_undo; for (policy_idx = 0; policy_idx < state->n_alloc && state->policies[policy_idx].policy; @@ -164,7 +164,7 @@ int netlink_policy_dump_add_policy(struc policy[type].nested_policy, policy[type].len); if (err) - return err; + goto err_try_undo; break; default: break; @@ -174,6 +174,16 @@ int netlink_policy_dump_add_policy(struc *pstate = state; return 0; + +err_try_undo: + /* Try to preserve reasonable unwind semantics - if we're starting from + * scratch clean up fully, otherwise record what we got and caller will. + */ + if (!*pstate) + netlink_policy_dump_free(state); + else + *pstate = state; + return err; } static bool