Hi,
On 8/12/21 3:43 PM, Bill Schmidt via Gcc-patches wrote:
Per discussion with Martin, I'm also changing the post-increment to
pre-increment in safe_inc_pos. That's what I'm regstrapping at the moment.
Thanks,
Bill
On 8/12/21 3:28 PM, Bill Schmidt via Gcc-patches wrote:
Although safe_inc_pos avoids buffer overruns in rs6000-gen-builtins.c,
there are some other routines where we fail to detect the possibility.
Clean those up!
Regstrap in progress on powerpc64le-linux-gnu. OK for trunk if that
passes?
Thanks,
Bill
Here's the final patch I tested, which passed regstrap. Ok for trunk?
Thanks!
Bill
From 8d8868a13c809381420f50f2d24bc060b73c3d4a Mon Sep 17 00:00:00 2001
Message-Id:
<8d8868a13c809381420f50f2d24bc060b73c3d4a.1628872666.git.wschm...@linux.ibm.com>
In-Reply-To:
<1af4993ea84c8a8deb204055325420189ca2350e.1628872665.git.wschm...@linux.ibm.com>
References:
<1af4993ea84c8a8deb204055325420189ca2350e.1628872665.git.wschm...@linux.ibm.com>
From: Bill Schmidt <wschm...@linux.ibm.com>
Date: Fri, 13 Aug 2021 11:35:55 -0500
Subject: [PATCH 35/35] rs6000: Avoid buffer overruns
2021-08-13 Bill Schmidt <wschm...@linux.ibm.com>
gcc/
PR target/101830
* config/rs6000/rs6000-gen-builtins.c (consume_whitespace):
Diagnose buffer overrun.
(safe_inc_pos): Fix overrun detection.
(match_identifier): Diagnose buffer overrun.
(match_integer): Likewise.
(match_to_right_bracket): Likewise.
---
gcc/config/rs6000/rs6000-gen-builtins.c | 34 ++++++++++++++++++++++---
1 file changed, 30 insertions(+), 4 deletions(-)
diff --git a/gcc/config/rs6000/rs6000-gen-builtins.c
b/gcc/config/rs6000/rs6000-gen-builtins.c
index 22902c37d55..503099464d6 100644
--- a/gcc/config/rs6000/rs6000-gen-builtins.c
+++ b/gcc/config/rs6000/rs6000-gen-builtins.c
@@ -638,6 +638,13 @@ consume_whitespace (void)
{
while (pos < LINELEN && isspace(linebuf[pos]) && linebuf[pos] != '\n')
pos++;
+
+ if (pos >= LINELEN)
+ {
+ diag (pos, "line length overrun.\n");
+ exit (1);
+ }
+
return;
}
@@ -684,7 +691,7 @@ advance_line (FILE *file)
static inline void
safe_inc_pos (void)
{
- if (pos++ >= LINELEN)
+ if (++pos >= LINELEN)
{
diag (pos, "line length overrun.\n");
exit (1);
@@ -697,9 +704,16 @@ static char *
match_identifier (void)
{
int lastpos = pos - 1;
- while (isalnum (linebuf[lastpos + 1]) || linebuf[lastpos + 1] == '_')
+ while (lastpos < LINELEN - 1
+ && (isalnum (linebuf[lastpos + 1]) || linebuf[lastpos + 1] == '_'))
++lastpos;
+ if (lastpos >= LINELEN - 1)
+ {
+ diag (lastpos, "line length overrun.\n");
+ exit (1);
+ }
+
if (lastpos < pos)
return 0;
@@ -721,9 +735,15 @@ match_integer (void)
safe_inc_pos ();
int lastpos = pos - 1;
- while (isdigit (linebuf[lastpos + 1]))
+ while (lastpos < LINELEN - 1 && isdigit (linebuf[lastpos + 1]))
++lastpos;
+ if (lastpos >= LINELEN - 1)
+ {
+ diag (lastpos, "line length overrun.\n");
+ exit (1);
+ }
+
if (lastpos < pos)
return NULL;
@@ -741,13 +761,19 @@ static const char *
match_to_right_bracket (void)
{
int lastpos = pos - 1;
- while (linebuf[lastpos + 1] != ']')
+ while (lastpos < LINELEN - 1 && linebuf[lastpos + 1] != ']')
{
if (linebuf[lastpos + 1] == '\n')
fatal ("no ']' found before end of line.\n");
++lastpos;
}
+ if (lastpos >= LINELEN - 1)
+ {
+ diag (lastpos, "line length overrun.\n");
+ exit (1);
+ }
+
if (lastpos < pos)
return 0;
--
2.27.0
