nasm: avoid null pointer reference on VERY early memory allocation failure

If we get a memory allocation failure before preproc is initialized,
we could end up taking a NULL pointer reference while trying to unwind
macros.

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

1 files changed, 2 insertions, 1 deletions

diff --git a/asm/nasm.c b/asm/nasm.c
index fd700df2..ac005edb 100644
--- a/asm/nasm.c
+++ b/asm/nasm.c
@@ -1927,7 +1927,8 @@ static void nasm_verror_asm(errflags severity, const char *fmt, va_list args)
 
     /* error_list_macros can for obvious reasons not work with ERR_HERE */
     if (!(severity & ERR_HERE))
-        preproc->error_list_macros(severity);
+        if (preproc)
+            preproc->error_list_macros(severity);
 
     switch (true_type) {
     case ERR_LISTMSG: