2023-11-02 19:17:47

by Philipp Stanner

[permalink] [raw]
Subject: [PATCH] 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.

Suggested-by: Dave Airlie <[email protected]>
Signed-off-by: Philipp Stanner <[email protected]>
---
drivers/media/dvb-core/dvb_frontend.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/media/dvb-core/dvb_frontend.c b/drivers/media/dvb-core/dvb_frontend.c
index 9293b058ab99..93d3378a0df4 100644
--- a/drivers/media/dvb-core/dvb_frontend.c
+++ b/drivers/media/dvb-core/dvb_frontend.c
@@ -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);

--
2.41.0