[media] ivtv: Return EFAULT when copy_from_user() fails in ivtv_write_vbi_from_user()

If write() on a VBI device node fails due to a bad buffer pointer from
userspace, we should notify the application properly with EFAULT, per the
V4L2 API spec.

Signed-off-by: Andy Walls <awalls@md.metrocast.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
This commit is contained in:
Andy Walls 2010-12-19 21:59:56 -03:00 committed by Mauro Carvalho Chehab
parent b0c45686c8
commit ddda424999
3 changed files with 15 additions and 9 deletions

View File

@ -570,9 +570,8 @@ ssize_t ivtv_v4l2_write(struct file *filp, const char __user *user_buf, size_t c
int elems = count / sizeof(struct v4l2_sliced_vbi_data);
set_bit(IVTV_F_S_APPL_IO, &s->s_flags);
ivtv_write_vbi_from_user(itv,
return ivtv_write_vbi_from_user(itv,
(const struct v4l2_sliced_vbi_data __user *)user_buf, elems);
return elems * sizeof(struct v4l2_sliced_vbi_data);
}
mode = s->type == IVTV_DEC_STREAM_TYPE_MPG ? OUT_MPG : OUT_YUV;

View File

@ -157,24 +157,30 @@ static void ivtv_write_vbi(struct ivtv *itv,
ivtv_write_vbi_cc_lines(itv, &cc);
}
void ivtv_write_vbi_from_user(struct ivtv *itv,
const struct v4l2_sliced_vbi_data __user *sliced,
size_t cnt)
ssize_t
ivtv_write_vbi_from_user(struct ivtv *itv,
const struct v4l2_sliced_vbi_data __user *sliced,
size_t cnt)
{
struct vbi_cc cc = { .odd = { 0x80, 0x80 }, .even = { 0x80, 0x80 } };
int found_cc = 0;
size_t i;
struct v4l2_sliced_vbi_data d;
ssize_t ret = cnt * sizeof(struct v4l2_sliced_vbi_data);
for (i = 0; i < cnt; i++) {
if (copy_from_user(&d, sliced + i,
sizeof(struct v4l2_sliced_vbi_data)))
sizeof(struct v4l2_sliced_vbi_data))) {
ret = -EFAULT;
break;
}
ivtv_write_vbi_line(itv, sliced + i, &cc, &found_cc);
}
if (found_cc)
ivtv_write_vbi_cc_lines(itv, &cc);
return ret;
}
static void copy_vbi_data(struct ivtv *itv, int lines, u32 pts_stamp)

View File

@ -20,9 +20,10 @@
#ifndef IVTV_VBI_H
#define IVTV_VBI_H
void ivtv_write_vbi_from_user(struct ivtv *itv,
const struct v4l2_sliced_vbi_data __user *sliced,
size_t count);
ssize_t
ivtv_write_vbi_from_user(struct ivtv *itv,
const struct v4l2_sliced_vbi_data __user *sliced,
size_t count);
void ivtv_process_vbi_data(struct ivtv *itv, struct ivtv_buffer *buf,
u64 pts_stamp, int streamtype);
int ivtv_used_line(struct ivtv *itv, int line, int field);