From: Thorsten Blum <thorsten.blum@linux.dev>
Date: Wed, 17 Sep 2025 13:13:47 +0000 (+0200)
Subject: comedi: Replace kcalloc + copy_from_user with memdup_array_user
X-Git-Tag: v6.19-rc1~65^2~83
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=48d45ae4ddaadaf67408cc588596a96b282ce2b4;p=thirdparty%2Fkernel%2Flinux.git

comedi: Replace kcalloc + copy_from_user with memdup_array_user

Replace kcalloc() followed by copy_from_user() with memdup_array_user()
to improve and simplify comedi_unlocked_ioctl().

No functional changes intended.

Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Link: https://patch.msgid.link/20250917131349.117642-2-thorsten.blum@linux.dev
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/comedi/comedi_fops.c b/drivers/comedi/comedi_fops.c
index 7e2f2b1a1c362..dea698e509b1b 100644
--- a/drivers/comedi/comedi_fops.c
+++ b/drivers/comedi/comedi_fops.c
@@ -2284,15 +2284,10 @@ static long comedi_unlocked_ioctl(struct file *file, unsigned int cmd,
 		rc = check_insnlist_len(dev, insnlist.n_insns);
 		if (rc)
 			break;
-		insns = kcalloc(insnlist.n_insns, sizeof(*insns), GFP_KERNEL);
-		if (!insns) {
-			rc = -ENOMEM;
-			break;
-		}
-		if (copy_from_user(insns, insnlist.insns,
-				   sizeof(*insns) * insnlist.n_insns)) {
-			rc = -EFAULT;
-			kfree(insns);
+		insns = memdup_array_user(insnlist.insns, insnlist.n_insns,
+					  sizeof(*insns));
+		if (IS_ERR(insns)) {
+			rc = PTR_ERR(insns);
 			break;
 		}
 		rc = do_insnlist_ioctl(dev, insns, insnlist.n_insns, file);