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 53D05C41513 for ; Wed, 9 Aug 2023 10:57:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232646AbjHIK52 (ORCPT ); Wed, 9 Aug 2023 06:57:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53278 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232930AbjHIK5M (ORCPT ); Wed, 9 Aug 2023 06:57:12 -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 7D4002125 for ; Wed, 9 Aug 2023 03:57:11 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 1474B62DC8 for ; Wed, 9 Aug 2023 10:57:11 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 24133C433C7; Wed, 9 Aug 2023 10:57:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1691578630; bh=EQ4ZQNWXbrWOvn9E46s0iU/rYrE5RbLdcOQhsusyyiE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=FTZMnIRJ6A/rPRsjdEqkJ6lJOU8GJmFi0i7dGwr9z6F/0y2v0oU/GLa2uNXt1kHIK A+ubnTLBNy5CwDn86pvkycOgb1ezu6hWI8asSrTF6tvSpjyp0Khboxrwj1aff0GGQC 8KQo8xDyZbOHh5UFte7jhh6RpLjnA1TRFkx27EK0= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, syzbot+aad58150cbc64ba41bdc@syzkaller.appspotmail.com, Prince Kumar Maurya , Christian Brauner Subject: [PATCH 6.1 102/127] fs/sysv: Null check to prevent null-ptr-deref bug Date: Wed, 9 Aug 2023 12:41:29 +0200 Message-ID: <20230809103639.998253601@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230809103636.615294317@linuxfoundation.org> References: <20230809103636.615294317@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: Prince Kumar Maurya commit ea2b62f305893992156a798f665847e0663c9f41 upstream. sb_getblk(inode->i_sb, parent) return a null ptr and taking lock on that leads to the null-ptr-deref bug. Reported-by: syzbot+aad58150cbc64ba41bdc@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=aad58150cbc64ba41bdc Signed-off-by: Prince Kumar Maurya Message-Id: <20230531013141.19487-1-princekumarmaurya06@gmail.com> Signed-off-by: Christian Brauner Signed-off-by: Greg Kroah-Hartman --- fs/sysv/itree.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/fs/sysv/itree.c +++ b/fs/sysv/itree.c @@ -145,6 +145,10 @@ static int alloc_branch(struct inode *in */ parent = block_to_cpu(SYSV_SB(inode->i_sb), branch[n-1].key); bh = sb_getblk(inode->i_sb, parent); + if (!bh) { + sysv_free_block(inode->i_sb, branch[n].key); + break; + } lock_buffer(bh); memset(bh->b_data, 0, blocksize); branch[n].bh = bh;