linux-kernel - [PATCH] block: floppy: Replace kmalloc() + copy_from_user() with memdup

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Message-ID: <20250908201021.439952-1-thorsten.blum@linux.dev>
Date: Mon,  8 Sep 2025 22:10:20 +0200
From: Thorsten Blum <thorsten.blum@...ux.dev>
To: Denis Efremov <efremov@...ux.com>,
	Jens Axboe <axboe@...nel.dk>
Cc: Thorsten Blum <thorsten.blum@...ux.dev>,
	linux-block@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: [PATCH] block: floppy: Replace kmalloc() + copy_from_user() with memdup_user()

Replace kmalloc() followed by copy_from_user() with memdup_user() to
improve and simplify raw_cmd_copyin().

No functional changes intended.

Signed-off-by: Thorsten Blum <thorsten.blum@...ux.dev>
---
 drivers/block/floppy.c | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c
index 24be0c2c4075..b33c6543ddf2 100644
--- a/drivers/block/floppy.c
+++ b/drivers/block/floppy.c
@@ -3092,16 +3092,13 @@ static int raw_cmd_copyin(int cmd, void __user *param,
 	*rcmd = NULL;
 
 loop:
-	ptr = kmalloc(sizeof(struct floppy_raw_cmd), GFP_KERNEL);
-	if (!ptr)
-		return -ENOMEM;
+	ptr = memdup_user(param, sizeof(*ptr));
+	if (IS_ERR(ptr))
+		return PTR_ERR(ptr);
 	*rcmd = ptr;
-	ret = copy_from_user(ptr, param, sizeof(*ptr));
 	ptr->next = NULL;
 	ptr->buffer_length = 0;
 	ptr->kernel_data = NULL;
-	if (ret)
-		return -EFAULT;
 	param += sizeof(struct floppy_raw_cmd);
 	if (ptr->cmd_count > FD_RAW_CMD_FULLSIZE)
 		return -EINVAL;
-- 
2.51.0