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authorSam Ravnborg <sam@ravnborg.org>2006-03-16 23:04:08 -0800
committerLinus Torvalds <torvalds@g5.osdl.org>2006-03-17 07:51:25 -0800
commit7670f023aabd976c25862e4c6fb9f6d9d2758153 (patch)
tree13c1c1fe41028f1f4752e10eef1a162b4f38c937 /scripts
parent85c6932ef0c7a82c309f8728ddf29768001d794e (diff)
downloadlinux-7670f023aabd976c25862e4c6fb9f6d9d2758153.tar.gz
[PATCH] kbuild: fix buffer overflow in modpost
Jiri Benc <jbenc@suse.cz> reported that modpost would stop with SIGABRT if
used with long filepaths.
The error looked like:
>   Building modules, stage 2.
>   MODPOST
> *** glibc detected *** scripts/mod/modpost: realloc(): invalid next size:
+0x0809f588 ***
> [...]

Fix this by allocating at least the required memory + SZ bytes each time.
Before we sometimes ended up allocating too little memory resuting in the
glibc detected bug above.  Based on patch originally submitted by: Jiri
Benc <jbenc@suse.cz>

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'scripts')
-rw-r--r--scripts/mod/modpost.c9
1 files changed, 2 insertions, 7 deletions
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index f70ff13d4818..b8b2a560b26b 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -508,12 +508,7 @@ buf_printf(struct buffer *buf, const char *fmt, ...)
 	
 	va_start(ap, fmt);
 	len = vsnprintf(tmp, SZ, fmt, ap);
-	if (buf->size - buf->pos < len + 1) {
-		buf->size += 128;
-		buf->p = realloc(buf->p, buf->size);
-	}
-	strncpy(buf->p + buf->pos, tmp, len + 1);
-	buf->pos += len;
+	buf_write(buf, tmp, len);
 	va_end(ap);
 }
 
@@ -521,7 +516,7 @@ void
 buf_write(struct buffer *buf, const char *s, int len)
 {
 	if (buf->size - buf->pos < len) {
-		buf->size += len;
+		buf->size += len + SZ;
 		buf->p = realloc(buf->p, buf->size);
 	}
 	strncpy(buf->p + buf->pos, s, len);