linux-kernel - [PATCH 5.10 349/545] platform/olpc: Fix uninitialized data in debugfs write

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

Message-Id: <20220819153844.995199967@linuxfoundation.org>
Date:   Fri, 19 Aug 2022 17:41:59 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Dan Carpenter <dan.carpenter@...cle.com>,
        Hans de Goede <hdegoede@...hat.com>,
        Sasha Levin <sashal@...nel.org>
Subject: [PATCH 5.10 349/545] platform/olpc: Fix uninitialized data in debugfs write

From: Dan Carpenter <dan.carpenter@...cle.com>

[ Upstream commit 40ec787e1adf302c11668d4cc69838f4d584187d ]

The call to:

	size = simple_write_to_buffer(cmdbuf, sizeof(cmdbuf), ppos, buf, size);

will succeed if at least one byte is written to the "cmdbuf" buffer.
The "*ppos" value controls which byte is written.  Another problem is
that this code does not check for errors so it's possible for the entire
buffer to be uninitialized.

Inintialize the struct to zero to prevent reading uninitialized stack
data.

Debugfs is normally only writable by root so the impact of this bug is
very minimal.

Fixes: 6cca83d498bd ("Platform: OLPC: move debugfs support from x86 EC driver")
Signed-off-by: Dan Carpenter <dan.carpenter@...cle.com>
Link: https://lore.kernel.org/r/YthIKn+TfZSZMEcM@kili
Reviewed-by: Hans de Goede <hdegoede@...hat.com>
Signed-off-by: Hans de Goede <hdegoede@...hat.com>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/platform/olpc/olpc-ec.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/platform/olpc/olpc-ec.c b/drivers/platform/olpc/olpc-ec.c
index 2db7113383fd..89d9fca02fe9 100644
--- a/drivers/platform/olpc/olpc-ec.c
+++ b/drivers/platform/olpc/olpc-ec.c
@@ -265,7 +265,7 @@ static ssize_t ec_dbgfs_cmd_write(struct file *file, const char __user *buf,
 	int i, m;
 	unsigned char ec_cmd[EC_MAX_CMD_ARGS];
 	unsigned int ec_cmd_int[EC_MAX_CMD_ARGS];
-	char cmdbuf[64];
+	char cmdbuf[64] = "";
 	int ec_cmd_bytes;
 
 	mutex_lock(&ec_dbgfs_lock);
-- 
2.35.1