Fix bugs in [v]snprintf usage
When calling snprintf, supply the full buffer size instead of
one byte less.
When using the returned length from vsnprintf for logging, don't write
more than the actual buffer size (minus one for the trailing \0), in
case the formatted string was truncated.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/engines/falloc.c b/engines/falloc.c
index 525a0aa..4654fe8 100644
--- a/engines/falloc.c
+++ b/engines/falloc.c
@@ -44,7 +44,7 @@
if (f->fd == -1) {
char buf[FIO_VERROR_SIZE];
int __e = errno;
- snprintf(buf, sizeof(buf) - 1, "open(%s)", f->file_name);
+ snprintf(buf, sizeof(buf), "open(%s)", f->file_name);
td_verror(td, __e, buf);
}
diff --git a/filesetup.c b/filesetup.c
index 6f0a876..5aadf12 100644
--- a/filesetup.c
+++ b/filesetup.c
@@ -563,7 +563,7 @@
if (__e == EMFILE && file_close_shadow_fds(td))
goto open_again;
- snprintf(buf, sizeof(buf) - 1, "open(%s)", f->file_name);
+ snprintf(buf, sizeof(buf), "open(%s)", f->file_name);
if (__e == EINVAL && (flags & OS_O_DIRECT)) {
log_err("fio: looks like your file system does not " \
@@ -1250,7 +1250,7 @@
if (!D) {
char buf[FIO_VERROR_SIZE];
- snprintf(buf, FIO_VERROR_SIZE - 1, "opendir(%s)", dirname);
+ snprintf(buf, FIO_VERROR_SIZE, "opendir(%s)", dirname);
td_verror(td, errno, buf);
return 1;
}
diff --git a/fio.h b/fio.h
index 2fd354a..d18029a 100644
--- a/fio.h
+++ b/fio.h
@@ -568,7 +568,7 @@
int e = (err); \
(td)->error = e; \
if (!(td)->first_error) \
- snprintf(td->verror, sizeof(td->verror) - 1, "file:%s:%d, func=%s, error=%s", __FILE__, __LINE__, (func), (msg)); \
+ snprintf(td->verror, sizeof(td->verror), "file:%s:%d, func=%s, error=%s", __FILE__, __LINE__, (func), (msg)); \
} while (0)
diff --git a/init.c b/init.c
index f0ad019..dfc5a8f 100644
--- a/init.c
+++ b/init.c
@@ -627,7 +627,7 @@
p++;
} while (*p);
- snprintf(buf, 31, "%u%c", val, *p);
+ snprintf(buf, 32, "%u%c", val, *p);
return buf;
}
diff --git a/iolog.c b/iolog.c
index 12f09d0..e4c1fef 100644
--- a/iolog.c
+++ b/iolog.c
@@ -534,7 +534,7 @@
{
char file_name[256], *p;
- snprintf(file_name, 200, "%s_%s.log", prefix, postfix);
+ snprintf(file_name, sizeof(file_name), "%s_%s.log", prefix, postfix);
p = basename(file_name);
__finish_log(log, p);
}
diff --git a/log.c b/log.c
index af974f8..08509b3 100644
--- a/log.c
+++ b/log.c
@@ -12,6 +12,7 @@
size_t len;
len = vsnprintf(buffer, sizeof(buffer), str, args);
+ len = min(len, sizeof(buffer) - 1);
if (log_syslog)
syslog(LOG_INFO, "%s", buffer);
@@ -40,6 +41,7 @@
va_start(args, format);
len = vsnprintf(buffer, sizeof(buffer), format, args);
va_end(args);
+ len = min(len, sizeof(buffer) - 1);
if (log_syslog)
syslog(LOG_INFO, "%s", buffer);
@@ -58,6 +60,7 @@
va_start(args, format);
len = vsnprintf(buffer, sizeof(buffer), format, args);
va_end(args);
+ len = min(len, sizeof(buffer) - 1);
if (is_backend)
return fio_server_text_output(buffer, len);
@@ -77,6 +80,7 @@
va_start(args, format);
len = vsnprintf(buffer, sizeof(buffer), format, args);
va_end(args);
+ len = min(len, sizeof(buffer) - 1);
if (is_backend)
return fio_server_text_output(buffer, len);
diff --git a/server.c b/server.c
index 7ec8531..ad78572 100644
--- a/server.c
+++ b/server.c
@@ -811,6 +811,7 @@
va_start(args, format);
len = vsnprintf(buffer, sizeof(buffer), format, args);
va_end(args);
+ len = min(len, sizeof(buffer) - 1);
return fio_server_text_output(buffer, len);
}
diff --git a/stat.c b/stat.c
index 7e2feea..62eee9a 100644
--- a/stat.c
+++ b/stat.c
@@ -753,7 +753,7 @@
json_object_add_value_int(percentile_object, "0.00", 0);
continue;
}
- snprintf(buf, sizeof(buf) - 1, "%2.2f", ts->percentile_list[i].u.f);
+ snprintf(buf, sizeof(buf), "%2.2f", ts->percentile_list[i].u.f);
json_object_add_value_int(percentile_object, (const char *)buf, ovals[i]);
}
@@ -959,9 +959,9 @@
for (i = 0; i < 7; i++) {
char name[20];
if (i < 6)
- snprintf(name, 19, "%d", 1 << i);
+ snprintf(name, 20, "%d", 1 << i);
else
- snprintf(name, 19, ">=%d", 1 << i);
+ snprintf(name, 20, ">=%d", 1 << i);
json_object_add_value_float(tmp, (const char *)name, io_u_dist[i]);
}
diff --git a/t/log.c b/t/log.c
index ac02303..76ae68e 100644
--- a/t/log.c
+++ b/t/log.c
@@ -10,6 +10,7 @@
va_start(args, format);
len = vsnprintf(buffer, sizeof(buffer), format, args);
va_end(args);
+ len = min(len, sizeof(buffer) - 1);
return fwrite(buffer, len, 1, stderr);
}
@@ -23,6 +24,7 @@
va_start(args, format);
len = vsnprintf(buffer, sizeof(buffer), format, args);
va_end(args);
+ len = min(len, sizeof(buffer) - 1);
return fwrite(buffer, len, 1, stdout);
}