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From: Tzung-Bi Shih <tzungbi@kernel.org>
To: bleung@chromium.org, groeck@chromium.org
Cc: chrome-platform@lists.linux.dev, tzungbi@kernel.org
Subject: [PATCH] platform/chrome: cros_ec_chardev: fix kernel data leak from ioctl
Date: Fri, 24 Mar 2023 09:06:58 +0800	[thread overview]
Message-ID: <20230324010658.1082361-1-tzungbi@kernel.org> (raw)

It is possible to peep kernel page's data by providing larger `insize`
in struct cros_ec_command[1] when invoking EC host commands.

Fix it by using zeroed memory.

[1]: https://elixir.bootlin.com/linux/v6.2/source/include/linux/platform_data/cros_ec_proto.h#L74

Fixes: eda2e30c6684 ("mfd / platform: cros_ec: Miscellaneous character device to talk with the EC")
Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>
---
 drivers/platform/chrome/cros_ec_chardev.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/platform/chrome/cros_ec_chardev.c b/drivers/platform/chrome/cros_ec_chardev.c
index 0de7c255254e..d6de5a294128 100644
--- a/drivers/platform/chrome/cros_ec_chardev.c
+++ b/drivers/platform/chrome/cros_ec_chardev.c
@@ -284,7 +284,7 @@ static long cros_ec_chardev_ioctl_xcmd(struct cros_ec_dev *ec, void __user *arg)
 	    u_cmd.insize > EC_MAX_MSG_BYTES)
 		return -EINVAL;
 
-	s_cmd = kmalloc(sizeof(*s_cmd) + max(u_cmd.outsize, u_cmd.insize),
+	s_cmd = kzalloc(sizeof(*s_cmd) + max(u_cmd.outsize, u_cmd.insize),
 			GFP_KERNEL);
 	if (!s_cmd)
 		return -ENOMEM;
-- 
2.40.0.348.gf938b09366-goog


             reply	other threads:[~2023-03-24  1:07 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-03-24  1:06 Tzung-Bi Shih [this message]
2023-03-24  1:24 ` [PATCH] platform/chrome: cros_ec_chardev: fix kernel data leak from ioctl Guenter Roeck
2023-03-24  3:20 ` patchwork-bot+chrome-platform
2023-03-24  3:40 ` patchwork-bot+chrome-platform

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