git: 1e6afe0f7d23 - stable/12 - Fix bad libbxo format strings in jls

[Kyle Evans]

The branch stable/12 has been updated by kevans:

URL: https://cgit.FreeBSD.org/src/commit/?id=1e6afe0f7d2346ac5b864b6b01bb9458f5349347

commit 1e6afe0f7d2346ac5b864b6b01bb9458f5349347
Author:     Alex Richardson <arichardson at FreeBSD.org>
AuthorDate: 2020-11-04 14:31:52 +0000
Commit:     Kyle Evans <kevans at FreeBSD.org>
CommitDate: 2021-01-02 05:27:10 +0000

    Fix bad libbxo format strings in jls
    
    The existing format string for the empty case was trying to read varargs
    values that weren't passed to xo_emit. This appears to work on x86 (since
    the next argument is probably a pointer an empty string), but for CHERI
    we can bound variadic arguments and detect a read past the end.
    
    While touching these lines also use the libxo 'a' modifier to avoid having to
    construct the libxo format string using asprintf.
    
    Found by:       CHERI
    Reviewed By:    allanjude
    Differential Revision: https://reviews.freebsd.org/D26885
    
    (cherry picked from commit d24f17df969107b47af60e5ccc1ed0f1a467fc6f)
---
 usr.sbin/jls/jls.c | 10 ++--------
 1 file changed, 2 insertions(+), 8 deletions(-)

diff --git a/usr.sbin/jls/jls.c b/usr.sbin/jls/jls.c
index 46c5a5c8b15e..374ee14bf080 100644
--- a/usr.sbin/jls/jls.c
+++ b/usr.sbin/jls/jls.c
@@ -505,17 +505,13 @@ quoted_print(int pflags, char *name, char *value)
 {
 	int qc;
 	char *p = value;
-	char *param_name_value;
 
 	/* An empty string needs quoting. */
 	if (!*p) {
-		asprintf(&param_name_value, "{k:%s}{d:%s/\"\"}", name, name);
-		xo_emit(param_name_value);
-		free(param_name_value);
+		xo_emit("{ea:/%s}{da:/\"\"}", name, value, name);
 		return;
 	}
 
-	asprintf(&param_name_value, "{:%s/%%s}", name);
 	/*
 	 * The value will be surrounded by quotes if it contains spaces
 	 * or quotes.
@@ -528,9 +524,7 @@ quoted_print(int pflags, char *name, char *value)
 	if (qc && pflags & PRINT_QUOTED)
 		xo_emit("{P:/%c}", qc);
 
-	xo_emit(param_name_value, value);
-
-	free(param_name_value);
+	xo_emit("{a:/%s}", name, value);
 
 	if (qc && pflags & PRINT_QUOTED)
 		xo_emit("{P:/%c}", qc);