linux-kernel - [PATCH] ibmasm: Replace kzalloc() + copy_from_user() with memdup_user

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Message-ID: <20250905103247.423840-2-thorsten.blum@linux.dev>
Date: Fri,  5 Sep 2025 12:32:44 +0200
From: Thorsten Blum <thorsten.blum@...ux.dev>
To: Arnd Bergmann <arnd@...db.de>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc: Thorsten Blum <thorsten.blum@...ux.dev>,
	linux-kernel@...r.kernel.org
Subject: [PATCH] ibmasm: Replace kzalloc() + copy_from_user() with memdup_user_nul()

Replace kzalloc() followed by copy_from_user() with memdup_user_nul() to
improve and simplify remote_settings_file_write().

No functional changes intended.

Signed-off-by: Thorsten Blum <thorsten.blum@...ux.dev>
---
 drivers/misc/ibmasm/ibmasmfs.c | 12 +++---------
 1 file changed, 3 insertions(+), 9 deletions(-)

diff --git a/drivers/misc/ibmasm/ibmasmfs.c b/drivers/misc/ibmasm/ibmasmfs.c
index c44de892a61e..2d5c1df82732 100644
--- a/drivers/misc/ibmasm/ibmasmfs.c
+++ b/drivers/misc/ibmasm/ibmasmfs.c
@@ -525,15 +525,9 @@ static ssize_t remote_settings_file_write(struct file *file, const char __user *
 	if (*offset != 0)
 		return 0;
 
-	buff = kzalloc (count + 1, GFP_KERNEL);
-	if (!buff)
-		return -ENOMEM;
-
-
-	if (copy_from_user(buff, ubuff, count)) {
-		kfree(buff);
-		return -EFAULT;
-	}
+	buff = memdup_user_nul(ubuff, count);
+	if (IS_ERR(buff))
+		return PTR_ERR(buff);
 
 	value = simple_strtoul(buff, NULL, 10);
 	writel(value, address);
-- 
2.51.0