s390/pkey: Use kfree_sensitive() to fix Coccinelle warnings

[ Upstream commit 22e6824 ]

Replace memzero_explicit() and kfree() with kfree_sensitive() to fix
warnings reported by Coccinelle:

WARNING opportunity for kfree_sensitive/kvfree_sensitive (line 1506)
WARNING opportunity for kfree_sensitive/kvfree_sensitive (line 1643)
WARNING opportunity for kfree_sensitive/kvfree_sensitive (line 1770)

Signed-off-by: Jules Irenge <[email protected]>
Reviewed-by: Holger Dengler <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Heiko Carstens <[email protected]>
Signed-off-by: Alexander Gordeev <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
(backported from commit 62151a0acde90823bdfa991d598c85cf4b1d387d linux-6.9.y)
[mpellizzer: backported solving merge conflicts caused by surrounding
instructions which do not affect the patch]
CVE-2024-42158
Signed-off-by: Massimiliano Pellizzer <[email protected]>
Acked-by: Guoqing Jiang <[email protected]>
Acked-by: Manuel Diewald <[email protected]>
Acked-by: Ivan Hu <[email protected]>
Signed-off-by: Roxana Nicolescu <[email protected]>

Author: irenge

drivers/s390/crypto/pkey_api.c

@@ -1286,8 +1286,7 @@ static long pkey_unlocked_ioctl(struct file *filp, unsigned int cmd,
 			return PTR_ERR(kkey);
 		rc = pkey_keyblob2pkey(kkey, ktp.keylen, &ktp.protkey);
 		DEBUG_DBG("%s pkey_keyblob2pkey()=%d\n", __func__, rc);
-		memzero_explicit(kkey, ktp.keylen);
-		kfree(kkey);
+		kfree_sensitive(kkey);
 		if (rc)
 			break;
 		if (copy_to_user(utp, &ktp, sizeof(ktp)))
@@ -1420,8 +1419,7 @@ static long pkey_unlocked_ioctl(struct file *filp, unsigned int cmd,
 					kkey, ktp.keylen, &ktp.protkey);
 		DEBUG_DBG("%s pkey_keyblob2pkey2()=%d\n", __func__, rc);
 		kfree(apqns);
-		memzero_explicit(kkey, ktp.keylen);
-		kfree(kkey);
+		kfree_sensitive(kkey);
 		if (rc)
 			break;
 		if (copy_to_user(utp, &ktp, sizeof(ktp)))
@@ -1547,8 +1545,7 @@ static long pkey_unlocked_ioctl(struct file *filp, unsigned int cmd,
 					protkey, &protkeylen);
 		DEBUG_DBG("%s pkey_keyblob2pkey3()=%d\n", __func__, rc);
 		kfree(apqns);
-		memzero_explicit(kkey, ktp.keylen);
-		kfree(kkey);
+		kfree_sensitive(kkey);
 		if (rc) {
 			kfree(protkey);
 			break;