[nasm:nasm-2.16.xx] BR 3392892: fix memory leak related to BR 3392414

[nasm-bot for C. Masloch]

Commit-ID:  d48839780d9060d4bf8cff9851c837b89302c194
Gitweb:     http://repo.or.cz/w/nasm.git?a=commitdiff;h=d48839780d9060d4bf8cff9851c837b89302c194
Author:     C. Masloch <pushbx at ulukai.org>
AuthorDate: Wed, 11 Oct 2023 13:57:04 -0700
Committer:  H. Peter Anvin <hpa at zytor.com>
CommitDate: Wed, 11 Oct 2023 13:58:48 -0700

BR 3392892: fix memory leak related to BR 3392414

The fix for BR 3392414 introduced a fairly serious memory
leak. C. Masloch was kind enough to track down the proper root cause
and fix it correctly.

Signed-off-by: H. Peter Anvin <hpa at zytor.com>


---
 asm/preproc.c | 12 +++---------
 1 file changed, 3 insertions(+), 9 deletions(-)

diff --git a/asm/preproc.c b/asm/preproc.c
index ac42131e..055f18b8 100644
--- a/asm/preproc.c
+++ b/asm/preproc.c
@@ -7640,10 +7640,12 @@ static Token *pp_tokline(void)
 #endif
                     {
                         nasm_free(m->params);
+                        nasm_free(m->iname);
                         free_tlist(m->iline);
                         nasm_free(m->paramlen);
                         fm->in_progress = 0;
 			m->params = NULL;
+                        m->iname = NULL;
 			m->iline = NULL;
 			m->paramlen = NULL;
                     }
@@ -7667,16 +7669,8 @@ static Token *pp_tokline(void)
 
                 istk->where = l->where;
 
-                /*
-                 * FIXME It is incorrect to always free_mmacro here.
-                 * It leads to usage-after-free.
-                 *
-                 * https://bugzilla.nasm.us/show_bug.cgi?id=3392414
-                 */
-#if 0
-                else
+                if (!m->name)
                     free_mmacro(m);
-#endif
             }
             istk->expansion = l->next;
             nasm_free(l);