drivers/media/dvb-core: copy user arrays safely

PATCH New Philipp Stanner 1 participant 1 message Nov 2, 2023 Media (V4L/DVB)

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Philipp Stanner

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2023-11-02 19:17 UTC #0 lore raw

PATCH 1/1 drivers/media/dvb-core: copy user arrays safely

At several positions in dvb_frontend.c, memdup_user() is utilized to copy userspace arrays. This is done without overflow checks.

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

Signed-off-by Philipp Stanner <[email protected]>

---
 drivers/media/dvb-core/dvb_frontend.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

drivers/media/dvb-core/dvb_frontend.c +8 -4

index 9293b058ab99..93d3378a0df4 100644
@@ -2168,7 +2168,8 @@ static int dvb_frontend_handle_compat_ioctl(struct file *file, unsigned int cmd,
 		if (!tvps->num || (tvps->num > DTV_IOCTL_MAX_MSGS))
 			return -EINVAL;
 
-		tvp = memdup_user(compat_ptr(tvps->props), tvps->num * sizeof(*tvp));
+		tvp = memdup_array_user(compat_ptr(tvps->props),
+					tvps->num, sizeof(*tvp));
 		if (IS_ERR(tvp))
 			return PTR_ERR(tvp);

@@ -2199,7 +2200,8 @@ static int dvb_frontend_handle_compat_ioctl(struct file *file, unsigned int cmd,
 		if (!tvps->num || (tvps->num > DTV_IOCTL_MAX_MSGS))
 			return -EINVAL;
 
-		tvp = memdup_user(compat_ptr(tvps->props), tvps->num * sizeof(*tvp));
+		tvp = memdup_array_user(compat_ptr(tvps->props),
+					tvps->num, sizeof(*tvp));
 		if (IS_ERR(tvp))
 			return PTR_ERR(tvp);

@@ -2379,7 +2381,8 @@ static int dvb_get_property(struct dvb_frontend *fe, struct file *file,
 	if (!tvps->num || tvps->num > DTV_IOCTL_MAX_MSGS)
 		return -EINVAL;
 
-	tvp = memdup_user((void __user *)tvps->props, tvps->num * sizeof(*tvp));
+	tvp = memdup_array_user((void __user *)tvps->props,
+				tvps->num, sizeof(*tvp));
 	if (IS_ERR(tvp))
 		return PTR_ERR(tvp);

@@ -2457,7 +2460,8 @@ static int dvb_frontend_handle_ioctl(struct file *file,
 		if (!tvps->num || (tvps->num > DTV_IOCTL_MAX_MSGS))
 			return -EINVAL;
 
-		tvp = memdup_user((void __user *)tvps->props, tvps->num * sizeof(*tvp));
+		tvp = memdup_array_user((void __user *)tvps->props,
+					tvps->num, sizeof(*tvp));
 		if (IS_ERR(tvp))
 			return PTR_ERR(tvp);

Signature · 1 line

2.41.0