linux-kernel - [PATCH] mmc: block: fix free of uninitialized 'idata->buf'

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <1467991622-11036-1-git-send-email-ville@tuxera.com>
Date:	Fri, 8 Jul 2016 18:27:02 +0300
From:	Ville Viinikka <ville@...era.com>
To:	<ulf.hansson@...aro.org>, <linux-mmc@...r.kernel.org>,
	<linux-kernel@...r.kernel.org>
CC:	Ville Viinikka <ville@...era.com>
Subject: [PATCH] mmc: block: fix free of uninitialized 'idata->buf'

Set 'idata->buf' to NULL so that it never gets returned without
initialization. This fixes a bug where mmc_blk_ioctl_cmd() would
free both 'idata' and 'idata->buf' but 'idata->buf' was returned
uninitialized.

Fixes: 1ff8950c0433 ("mmc: block: change to use kmalloc when copy data from userspace")
Signed-off-by: Ville Viinikka <ville@...era.com>
---
 drivers/mmc/card/block.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
index 747c4b0..334d637 100644
--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -355,8 +355,10 @@ static struct mmc_blk_ioc_data *mmc_blk_ioctl_copy_from_user(
 		goto idata_err;
 	}
 
-	if (!idata->buf_bytes)
+	if (!idata->buf_bytes) {
+		idata->buf = NULL;
 		return idata;
+	}
 
 	idata->buf = kmalloc(idata->buf_bytes, GFP_KERNEL);
 	if (!idata->buf) {
-- 
2.1.4