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 56BBCC77B7D for ; Mon, 15 May 2023 18:10:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245129AbjEOSJ7 (ORCPT ); Mon, 15 May 2023 14:09:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47038 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S245049AbjEOSJl (ORCPT ); Mon, 15 May 2023 14:09:41 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 72C60203FE for ; Mon, 15 May 2023 11:07:20 -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 dfw.source.kernel.org (Postfix) with ESMTPS id B2103630E8 for ; Mon, 15 May 2023 18:07:19 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C05CCC433D2; Mon, 15 May 2023 18:07:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1684174039; bh=p7812dfwj5XKRnfaS6yIHNP+vH9kCHryajWqolBaZGs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PbYuDKYQdo/1XzQGiaFY3mJgez5wObIG//iFVkjQrn+ZXTDo5nYtRN3kqL6iFrXk1 wknWmzV7lSYDDlFx0FdnZ2Ze6tqJLEkfQaE6f9yQulm4LIgOonmYP3Eg0OnqADHC53 LI8kpqnZSGtcHuz4ilrsDAo4IvZFvSbGONxqXE3g= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, stable@kernel.org, syzbot+64b645917ce07d89bde5@syzkaller.appspotmail.com, syzbot+0d042627c4f2ad332195@syzkaller.appspotmail.com, Theodore Tso Subject: [PATCH 5.4 267/282] ext4: fix invalid free tracking in ext4_xattr_move_to_block() Date: Mon, 15 May 2023 18:30:45 +0200 Message-Id: <20230515161730.320800036@linuxfoundation.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230515161722.146344674@linuxfoundation.org> References: <20230515161722.146344674@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: Theodore Ts'o commit b87c7cdf2bed4928b899e1ce91ef0d147017ba45 upstream. In ext4_xattr_move_to_block(), the value of the extended attribute which we need to move to an external block may be allocated by kvmalloc() if the value is stored in an external inode. So at the end of the function the code tried to check if this was the case by testing entry->e_value_inum. However, at this point, the pointer to the xattr entry is no longer valid, because it was removed from the original location where it had been stored. So we could end up calling kvfree() on a pointer which was not allocated by kvmalloc(); or we could also potentially leak memory by not freeing the buffer when it should be freed. Fix this by storing whether it should be freed in a separate variable. Cc: stable@kernel.org Link: https://lore.kernel.org/r/20230430160426.581366-1-tytso@mit.edu Link: https://syzkaller.appspot.com/bug?id=5c2aee8256e30b55ccf57312c16d88417adbd5e1 Link: https://syzkaller.appspot.com/bug?id=41a6b5d4917c0412eb3b3c3c604965bed7d7420b Reported-by: syzbot+64b645917ce07d89bde5@syzkaller.appspotmail.com Reported-by: syzbot+0d042627c4f2ad332195@syzkaller.appspotmail.com Signed-off-by: Theodore Ts'o Signed-off-by: Greg Kroah-Hartman --- fs/ext4/xattr.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- a/fs/ext4/xattr.c +++ b/fs/ext4/xattr.c @@ -2569,6 +2569,7 @@ static int ext4_xattr_move_to_block(hand .in_inode = !!entry->e_value_inum, }; struct ext4_xattr_ibody_header *header = IHDR(inode, raw_inode); + int needs_kvfree = 0; int error; is = kzalloc(sizeof(struct ext4_xattr_ibody_find), GFP_NOFS); @@ -2591,7 +2592,7 @@ static int ext4_xattr_move_to_block(hand error = -ENOMEM; goto out; } - + needs_kvfree = 1; error = ext4_xattr_inode_get(inode, entry, buffer, value_size); if (error) goto out; @@ -2630,7 +2631,7 @@ static int ext4_xattr_move_to_block(hand out: kfree(b_entry_name); - if (entry->e_value_inum && buffer) + if (needs_kvfree && buffer) kvfree(buffer); if (is) brelse(is->iloc.bh);