From: Thorsten Blum <thorsten.blum@linux.dev>
Date: Fri, 5 Sep 2025 10:18:17 +0000 (+0200)
Subject: io_uring: Replace kzalloc() + copy_from_user() with memdup_user()
X-Git-Tag: v6.18-rc1~137^2~30
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=7b0604d77a41192316347618cce1d9c795613adb;p=thirdparty%2Fkernel%2Fstable.git

io_uring: Replace kzalloc() + copy_from_user() with memdup_user()

Replace kzalloc() followed by copy_from_user() with memdup_user() to
improve and simplify io_probe().

No functional changes intended.

Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---

diff --git a/io_uring/register.c b/io_uring/register.c
index 9c31a8afb83d2..f4c76db276836 100644
--- a/io_uring/register.c
+++ b/io_uring/register.c
@@ -47,13 +47,9 @@ static __cold int io_probe(struct io_ring_ctx *ctx, void __user *arg,
 		nr_args = IORING_OP_LAST;
 
 	size = struct_size(p, ops, nr_args);
-	p = kzalloc(size, GFP_KERNEL);
-	if (!p)
-		return -ENOMEM;
-
-	ret = -EFAULT;
-	if (copy_from_user(p, arg, size))
-		goto out;
+	p = memdup_user(arg, size);
+	if (IS_ERR(p))
+		return PTR_ERR(p);
 	ret = -EINVAL;
 	if (memchr_inv(p, 0, size))
 		goto out;