From: David Goulet <dgoulet@efficios.com>
Date: Tue, 22 Jan 2013 20:28:36 +0000 (-0500)
Subject: Fix: poll max size should be checked during resize
X-Git-Tag: v2.2.0-rc1~89
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=ac018a8b4890dcf6f0eb9d4b5dee600269e79b29;p=lttng-tools.git

Fix: poll max size should be checked during resize

This was detected using cppcheck:

[src/common/compat/compat-poll.c:204]: (error) Uninitialized variable:
new_size

So, the check was always made over an uninitialized variable on the
stack. Fortunately, worst case scenario, new_size is set to the maximum
allowed or kept untouched.

Signed-off-by: David Goulet <dgoulet@efficios.com>
---

diff --git a/src/common/compat/compat-poll.c b/src/common/compat/compat-poll.c
index cff9f44b8..bc79eed0a 100644
--- a/src/common/compat/compat-poll.c
+++ b/src/common/compat/compat-poll.c
@@ -40,6 +40,11 @@ static int resize_poll_event(struct compat_poll_event_array *array,
 
 	assert(array);
 
+	/* Refuse to resize the array more than the max size. */
+	if (new_size > poll_max_size) {
+		goto error;
+	}
+
 	ptr = realloc(array->events, new_size * sizeof(*ptr));
 	if (ptr == NULL) {
 		PERROR("realloc epoll add");
@@ -200,11 +205,6 @@ int compat_poll_del(struct lttng_poll_event *events, int fd)
 	/* Ease our life a bit. */
 	current = &events->current;
 
-	/* Safety check on size */
-	if (new_size > poll_max_size) {
-		new_size = poll_max_size;
-	}
-
 	/* Check if we need to shrink it down. */
 	if ((current->nb_fd << 1UL) <= current->alloc_size &&
 			current->nb_fd >= current->init_size) {