git: 4d8f612e5b26 - stable/15 - if_ovpn.c: fix use of uninitialized variable

The branch stable/15 has been updated by dim:

URL: https://cgit.FreeBSD.org/src/commit/?id=4d8f612e5b26469732252b7f727acd9e0271f6a6

commit 4d8f612e5b26469732252b7f727acd9e0271f6a6
Author:     Alex Richardson <arichardson@FreeBSD.org>
AuthorDate: 2025-09-15 22:08:43 +0000
Commit:     Dimitry Andric <dim@FreeBSD.org>
CommitDate: 2026-05-27 21:41:03 +0000

    if_ovpn.c: fix use of uninitialized variable
    
    In case we use OVPN_CIPHER_ALG_NONE, the memcpy will attempt to copy 0
    bytes from an uninitialized pointer. While the memcpy() implementation
    will treat this as a no-op and not actually dereferece the undefined
    variable it is still undefined behaviour to the compiler and should be
    fixed. Found by building with clang HEAD
    
    Reviewed by:    kp
    MFC after:      1 week
    Differential Revision: https://reviews.freebsd.org/D52543
    
    (cherry picked from commit 969be39fb3caf4272f128dbf3267ceba5966a6ce)
---
 sys/net/if_ovpn.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/sys/net/if_ovpn.c b/sys/net/if_ovpn.c
index 99c99369d22a..7c416055e939 100644
--- a/sys/net/if_ovpn.c
+++ b/sys/net/if_ovpn.c
@@ -914,9 +914,11 @@ ovpn_create_kkey_dir(struct ovpn_kkey_dir **kdirp,
 	kdir->cipher = cipher;
 	kdir->keylen = keylen;
 	kdir->tx_seq = 1;
-	memcpy(kdir->key, key, keylen);
+	if (keylen != 0)
+		memcpy(kdir->key, key, keylen);
 	kdir->noncelen = ivlen;
-	memcpy(kdir->nonce, iv, ivlen);
+	if (ivlen != 0)
+		memcpy(kdir->nonce, iv, ivlen);
 
 	if (kdir->cipher != OVPN_CIPHER_ALG_NONE) {
 		/* Crypto init */