From mboxrd@z Thu Jan 1 00:00:00 1970 Delivery-date: Sat, 19 Jun 2021 07:43:44 +0200 Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by lore.white.stw.pengutronix.de with esmtp (Exim 4.92) (envelope-from ) id 1luTlg-0005jO-Kv for lore@lore.pengutronix.de; Sat, 19 Jun 2021 07:43:44 +0200 Received: from bombadil.infradead.org ([2607:7c80:54:e::133]) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1luTlf-0006FK-Mg for lore@pengutronix.de; Sat, 19 Jun 2021 07:43:44 +0200 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-Id:Date:Subject:Cc :To:From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=olmbXNKNySQu8mCRXs2mL7IxR7MktuXZhbLcogbXs2E=; b=Mr56YSYpZBvzHO bfirRwppZ8bmo06V08r56AV3jtKhMDLV3f7uZtcFCO4nLero2fmP1q2iFWyyaN/KKfnjXCJuelYtt E1BUiHjj0B6w5H7hNQ851Z7IesS8X1xwxOJGI12jJhC15ibkIGQblINNr6bd3dhglsNIhM0kgX9b/ V1bNMYTAUA6Yn6c7MsHJIucixuJjmqAOuRD14/pN2Pku14bmOKqOzez8M27TgW8GY8bCWkZD/gv1P gEwdYrOfeGHE+xHo27swZM0HXLhLT9w7EjV3hrlMXlSICypIgGGEUuGiqViPu+sh6KHFXernJVCSY 6zsf1kr5rfmiaPzaRUSw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1luTkU-00GPsx-31; Sat, 19 Jun 2021 05:42:30 +0000 Received: from relay7-d.mail.gandi.net ([217.70.183.200]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1luTkO-00GPsO-Um for barebox@lists.infradead.org; Sat, 19 Jun 2021 05:42:26 +0000 Received: (Authenticated sender: ahmad@a3f.at) by relay7-d.mail.gandi.net (Postfix) with ESMTPSA id CC21320003; Sat, 19 Jun 2021 05:42:21 +0000 (UTC) From: Ahmad Fatoum To: barebox@lists.infradead.org Cc: Ahmad Fatoum Date: Sat, 19 Jun 2021 07:42:17 +0200 Message-Id: <20210619054217.499815-1-ahmad@a3f.at> X-Mailer: git-send-email 2.32.0.rc0 MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210618_224225_169729_F9A80279 X-CRM114-Status: UNSURE ( 9.45 ) X-CRM114-Notice: Please train this message. X-BeenThere: barebox@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "barebox" X-SA-Exim-Connect-IP: 2607:7c80:54:e::133 X-SA-Exim-Mail-From: barebox-bounces+lore=pengutronix.de@lists.infradead.org X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on metis.ext.pengutronix.de X-Spam-Level: X-Spam-Status: No, score=-5.2 required=4.0 tests=AWL,BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED,SPF_HELO_NONE,SPF_NONE autolearn=unavailable autolearn_force=no version=3.4.2 Subject: [PATCH] commands: md: don't leak heap memory with unaligned accesses X-SA-Exim-Version: 4.2.1 (built Wed, 08 May 2019 21:11:16 +0000) X-SA-Exim-Scanned: Yes (on metis.ext.pengutronix.de) Doing unaligned near file end returns bogus results: barebox@Sandbox:/ md -s /dev/stickypage 4095 00000fff: 959ff8ff . That 0x959ff8 is heap memory next to the buffer md had allocated. Fix this by adding some zeroed padding after the buffer, so it instead reads: 00000fff: 000000ff . This is arguably better user experience. This only applies to non-mappable fd's. For e.g. /dev/mem, unaligned accesses will still be passed as-is. Signed-off-by: Ahmad Fatoum --- commands/md.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/commands/md.c b/commands/md.c index ef6a1e1bc0b1..d80c7cca0ce4 100644 --- a/commands/md.c +++ b/commands/md.c @@ -59,7 +59,7 @@ static int do_mem_md(int argc, char *argv[]) goto out; } - buf = xmalloc(RW_BUF_SIZE); + buf = xzalloc(RW_BUF_SIZE + 7); do { now = min(size, (loff_t)RW_BUF_SIZE); -- 2.32.0.rc0 _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox