[PATCH] drm: zynqmp_dp: Fix uninitialized variable in debugfs()
Dan Carpenter <[email protected]>
| Newsgroups | org.kernel.vger.kernel-janitors,org.freedesktop.lists.dri-devel,org.infradead.lists.linux-arm-kernel,org.kernel.vger.linux-kernel |
|---|---|
| Message-ID | <[email protected]> |
If the *ppos is non-zero then simple_write_to_buffer() will not
initialize the start of the buf[] buffer. It doesn't really make sense
to allow non-zero values for *ppos, so check for that at the start and
return -EINVAL.
Fixes: 28edaacb821c ("drm: zynqmp_dp: Add debugfs interface for compliance testing")
Signed-off-by: Dan Carpenter <[email protected]>
---
drivers/gpu/drm/xlnx/zynqmp_dp.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/gpu/drm/xlnx/zynqmp_dp.c b/drivers/gpu/drm/xlnx/zynqmp_dp.c
index 7fb11b0a44f0..847179476041 100644
--- a/drivers/gpu/drm/xlnx/zynqmp_dp.c
+++ b/drivers/gpu/drm/xlnx/zynqmp_dp.c
@@ -1888,6 +1888,9 @@ static ssize_t zynqmp_dp_pattern_write(struct file *file,
ssize_t ret;
int pattern;
+ if (*ppos != 0)
+ return -EINVAL;
+
ret = simple_write_to_buffer(buf, sizeof(buf) - 1, ppos, user_buf,
count);
if (ret < 0)
@@ -2028,6 +2031,9 @@ static ssize_t zynqmp_dp_custom_write(struct file *file,
ssize_t ret;
char buf[sizeof(dp->test.custom)];
+ if (*ppos != 0)
+ return -EINVAL;
+
ret = simple_write_to_buffer(buf, sizeof(buf), ppos, user_buf, count);
if (ret < 0)
return ret;
--
2.53.0