kvx: asan: out-of-bounds read

Message ID ZOVkLP7thqPpuUoI@squeak.grove.modra.org
State Unresolved
Headers
Series kvx: asan: out-of-bounds read |

Checks

Context Check Description
snail/binutils-gdb-check warning Git am fail log

Commit Message

Alan Modra Aug. 23, 2023, 1:43 a.m. UTC
  kvx-parse.c:parse_with_restarts does
  if (!tok.insn[tok.begin])
    tok.class_id = -3;
then a little later
  printf_debug (1, "\nEntering rule: %d (Trying to match: (%s)[%d])\n", jump_target,
		TOKEN_NAME (CLASS_ID (tok)), CLASS_ID (tok));

This results in a buffer overrun in TOKEN_NAME.  Fix that.

	* config/tc-kvx.h (TOKEN_NAME): Check for tok <= 0, not just -1.
  

Patch

diff --git a/gas/config/tc-kvx.h b/gas/config/tc-kvx.h
index 11787bf0532..85344cbe179 100644
--- a/gas/config/tc-kvx.h
+++ b/gas/config/tc-kvx.h
@@ -37,7 +37,8 @@ 
 #define KVX_RA_REGNO (67)
 #define KVX_SP_REGNO (12)
 
-#define TOKEN_NAME(tok) ((tok) == -1 ? "unknown token" : env.tokens_names[(tok) - 1])
+#define TOKEN_NAME(tok) \
+  ((tok) <= 0 ? "unknown token" : env.tokens_names[(tok) - 1])
 
 struct token_s {
   char *insn;