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From: Philipp Stanner <pstanner@redhat.com>
To: Wolfram Sang <wsa@kernel.org>
Cc: linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org,
	Philipp Stanner <pstanner@redhat.com>,
	Dave Airlie <airlied@redhat.com>
Subject: [PATCH] drivers/i2c: copy userspace array safely
Date: Thu,  2 Nov 2023 20:26:13 +0100	[thread overview]
Message-ID: <20231102192612.54066-2-pstanner@redhat.com> (raw)

i2c-dev.c utilizes memdup_user() to copy a userspace array. This is done
without an overflow check.

Use the new wrapper memdup_array_user() to copy the array more safely.

Suggested-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Philipp Stanner <pstanner@redhat.com>
---
 drivers/i2c/i2c-dev.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/i2c/i2c-dev.c b/drivers/i2c/i2c-dev.c
index a01b59e3599b..7d337380a05d 100644
--- a/drivers/i2c/i2c-dev.c
+++ b/drivers/i2c/i2c-dev.c
@@ -450,8 +450,8 @@ static long i2cdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 		if (rdwr_arg.nmsgs > I2C_RDWR_IOCTL_MAX_MSGS)
 			return -EINVAL;
 
-		rdwr_pa = memdup_user(rdwr_arg.msgs,
-				      rdwr_arg.nmsgs * sizeof(struct i2c_msg));
+		rdwr_pa = memdup_array_user(rdwr_arg.msgs,
+					    rdwr_arg.nmsgs, sizeof(struct i2c_msg));
 		if (IS_ERR(rdwr_pa))
 			return PTR_ERR(rdwr_pa);
 
-- 
2.41.0


             reply	other threads:[~2023-11-02 19:27 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-11-02 19:26 Philipp Stanner [this message]
2023-11-08  9:26 ` [PATCH] drivers/i2c: copy userspace array safely Wolfram Sang

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