[PATCH] accel/ivpu: prevent uninitialized data bug in debugfs

[Dan Carpenter]

The simple_write_to_buffer() will only initialize data starting from
the *pos offset so if it's non-zero then the first part of the buffer
uninitialized.  Really, if *pos is non-zero then this code won't work
so just check for that at the start of the function.

Fixes: 320323d2e545 ("accel/ivpu: Add debugfs interface for setting HWS priority bands")
Signed-off-by: Dan Carpenter <error27@xxxxxxxxx>
---
 drivers/accel/ivpu/ivpu_debugfs.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/accel/ivpu/ivpu_debugfs.c b/drivers/accel/ivpu/ivpu_debugfs.c
index 189dbe94cf14..dc20bc73c6ed 100644
--- a/drivers/accel/ivpu/ivpu_debugfs.c
+++ b/drivers/accel/ivpu/ivpu_debugfs.c
@@ -450,7 +450,7 @@ priority_bands_fops_write(struct file *file, const char __user *user_buf, size_t
 	u32 band;
 	int ret;
 
-	if (size >= sizeof(buf))
+	if (*pos != 0 || size >= sizeof(buf))
 		return -EINVAL;
 
 	ret = simple_write_to_buffer(buf, sizeof(buf) - 1, pos, user_buf, size);
-- 
2.53.0