Switch to memdup_user() to overwrite the allocated memory only once
instead of initializing the allocated memory to zero with kzalloc() and
then immediately overwriting it with copy_from_user().
Fix the following Coccinelle/coccicheck warning reported by
memdup_user.cocci:
WARNING opportunity for memdup_user
Signed-off-by: Thorsten Blum <thorsten.blum@xxxxxxxxxx>
---
Changes in v2:
- Update patch description after feedback from Markus Elfring
---
drivers/platform/x86/amd/pmf/tee-if.c | 11 +++--------
1 file changed, 3 insertions(+), 8 deletions(-)
diff --git a/drivers/platform/x86/amd/pmf/tee-if.c b/drivers/platform/x86/amd/pmf/tee-if.c
index b438de4d6bfc..1b53cabc9aa2 100644
--- a/drivers/platform/x86/amd/pmf/tee-if.c
+++ b/drivers/platform/x86/amd/pmf/tee-if.c
@@ -301,14 +301,9 @@ static ssize_t amd_pmf_get_pb_data(struct file *filp, const char __user *buf,
return -EINVAL;
/* re-alloc to the new buffer length of the policy binary */
- new_policy_buf = kzalloc(length, GFP_KERNEL);
- if (!new_policy_buf)
- return -ENOMEM;
-
- if (copy_from_user(new_policy_buf, buf, length)) {
- kfree(new_policy_buf);
- return -EFAULT;
- }
+ new_policy_buf = memdup_user(buf, length);
+ if (IS_ERR(new_policy_buf))
+ return PTR_ERR(new_policy_buf);
kfree(dev->policy_buf);
dev->policy_buf = new_policy_buf;
--
2.45.1
