sh: Avoid referencing uninitialized memory in alias

If run as
	alias ''
uninitialized memory could be referenced.

This is based on a fix from NetBSD.  For more information, refer to
https://github.com/NetBSD/src/commit/10cfed82c28 .

Obtained from:	NetBSD (Robert Elz <kre@netbsd.org>, 10cfed82c28)
MFC after:	3 days

Reported by:	mckusick, Robert Elz <kre@netbsd.org>
Reviewed by:	emaste
Differential Revision:	https://reviews.freebsd.org/D50364

This commit is contained in:

Joseph Mingrone

2025-05-15 11:42:14 -03:00

parent 413197cef9

commit 9d29fc2e4b

1 changed files with 5 additions and 0 deletions

									
										bin/sh/alias.c
									
		+5
		
												View File
												
				@@ -204,6 +204,11 @@ aliascmd(int argc __unused, char **argv __unused)

						return (0);

					}

					while ((n = *argptr++) != NULL) {

						if (n[0] == '\0') {

							warning("'': not found");

							ret = 1;

							continue;

						}

						if ((v = strchr(n+1, '=')) == NULL) /* n+1: funny ksh stuff */

							if ((ap = lookupalias(n, 0)) == NULL) {

								warning("%s: not found", n);