From: Kei Tokunaga <tokunaga.keiich@jp.fujitsu.com>
Date: Tue, 15 Feb 2011 09:59:24 +0000 (+0900)
Subject: udevadm: enumerate - update prev pointer properly
X-Git-Tag: 174~251
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c54b43e2c233e724f840c4f6a0a81bdd549e40bb;p=systemd

udevadm: enumerate - update prev pointer properly

When I tried to boot a system with 256 disks x 4 paths with
device-mapper, udevadm trigger (--type=devices) that was called
from start_udev ended up dumping a core due to a segmentation
fault.

In udev_enumerate_get_list_entry(), if it finds the devices that
should be delayed, it calls syspath_add().  If realloc() in
syspath_add() allocates the required memory at a different memory
address, referring prev->len afterward causes the segmentation
fault.

Signed-off-by: Kei Tokunaga <tokunaga.keiich@jp.fujitsu.com>
---

diff --git a/libudev/libudev-enumerate.c b/libudev/libudev-enumerate.c
index e46bc087..9694797d 100644
--- a/libudev/libudev-enumerate.c
+++ b/libudev/libudev-enumerate.c
@@ -274,6 +274,9 @@ struct udev_list_entry *udev_enumerate_get_list_entry(struct udev_enumerate *ude
 			/* skip to be delayed devices, and add them to the end of the list */
 			if (devices_delay_end(udev_enumerate->udev, entry->syspath)) {
 				syspath_add(udev_enumerate, entry->syspath);
+				/* need to update prev here for the case realloc() gives
+				   a different address */
+				prev = &udev_enumerate->devices[i];
 				continue;
 			}