init: fix potential buffer overrun in make_filename()
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/init.c b/init.c
index 6324dce..7e456b2 100644
--- a/init.c
+++ b/init.c
@@ -942,6 +942,7 @@
{
struct fpre_keyword *f;
char copy[PATH_MAX];
+ size_t dst_left = PATH_MAX;
if (!o->filename_format || !strlen(o->filename_format)) {
sprintf(buf, "%s.%d.%d", jobname, jobnum, filenum);
@@ -969,25 +970,47 @@
if (pre_len) {
strncpy(dst, buf, pre_len);
dst += pre_len;
+ dst_left -= pre_len;
}
switch (f->key) {
- case FPRE_JOBNAME:
- dst += sprintf(dst, "%s", jobname);
+ case FPRE_JOBNAME: {
+ int ret;
+
+ ret = snprintf(dst, dst_left, "%s", jobname);
+ if (ret < 0)
+ break;
+ dst += ret;
+ dst_left -= ret;
break;
- case FPRE_JOBNUM:
- dst += sprintf(dst, "%d", jobnum);
+ }
+ case FPRE_JOBNUM: {
+ int ret;
+
+ ret = snprintf(dst, dst_left, "%d", jobnum);
+ if (ret < 0)
+ break;
+ dst += ret;
+ dst_left -= ret;
break;
- case FPRE_FILENUM:
- dst += sprintf(dst, "%d", filenum);
+ }
+ case FPRE_FILENUM: {
+ int ret;
+
+ ret = snprintf(dst, dst_left, "%d", filenum);
+ if (ret < 0)
+ break;
+ dst += ret;
+ dst_left -= ret;
break;
+ }
default:
assert(0);
break;
}
if (post_start)
- strcpy(dst, buf + post_start);
+ strncpy(dst, buf + post_start, dst_left);
strcpy(buf, copy);
} while (1);