git: dec68aeff8ce - main - libc/stdlib/getenv.c: always allocate new environment

The branch main has been updated by kib:

URL: https://cgit.FreeBSD.org/src/commit/?id=dec68aeff8ce0ce154e93325a74bba6af71c87af

commit dec68aeff8ce0ce154e93325a74bba6af71c87af
Author:     Konstantin Belousov <kib@FreeBSD.org>
AuthorDate: 2026-09-24 18:30:57 +0000
Commit:     Konstantin Belousov <kib@FreeBSD.org>
CommitDate: 2026-10-02 19:48:42 +0000

    libc/stdlib/getenv.c:  always allocate new environment
    
    in particular, if the old environment is NULL.
    
    Among making it less surprising for userspace to observe NULL environ,
    the change also prevents NULL deref in __rebuild_environ() when
    terminating the empty as NULL environment with the NULL pointer.
    
    Reported by:     Leo Bicknell <bicknell@ufp.org>
    PR:     298747
    Reviewed by:    emaste, markj
    Sponsored by:   The FreeBSD Foundation
    MFC after:      1 week
    Differential revision:  https://reviews.freebsd.org/D59996
---
 lib/libc/stdlib/getenv.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/libc/stdlib/getenv.c b/lib/libc/stdlib/getenv.c
index c1d0b7a559d5..1fff081002e2 100644
--- a/lib/libc/stdlib/getenv.c
+++ b/lib/libc/stdlib/getenv.c
@@ -268,7 +268,7 @@ __rebuild_environ(int newEnvironSize)
 	int tmpEnvironSize;
 
 	/* Resize environ. */
-	if (newEnvironSize > environSize) {
+	if (newEnvironSize > environSize || intEnviron == NULL) {
 		tmpEnvironSize = newEnvironSize * 2;
 		tmpEnviron = reallocarray(intEnviron, tmpEnvironSize + 1,
 		    sizeof(*intEnviron));