[parted-devel] [PATCH] libparted: Fix udev cookie leak in _dm_resize_partition

[Brian C. Lane]

The function is setting udev cookies, but not using them when waiting
for the task. This results in leaked cookies, which can eventually
exhaust the available number of semaphores.

'dmsetup udevcookies' will show a cookie remaining afterwards, and 'ipcs -s'
will show the semaphores in use.

Also simplified the exit so that the task is always destroyed and memory
is all freed in the same path.

Resolves: rhbz#1455564
---
 libparted/arch/linux.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/libparted/arch/linux.c b/libparted/arch/linux.c
index 9886d6e..1a35964 100644
--- a/libparted/arch/linux.c
+++ b/libparted/arch/linux.c
@@ -2943,6 +2943,7 @@ _dm_resize_partition (PedDisk* disk, const PedPartition* part)
         char*           vol_name = NULL;
         const char*     dev_name = NULL;
         uint32_t        cookie = 0;
+        int             rc = 0;
 
         /* Get map name from devicemapper */
         struct dm_task *task = dm_task_create (DM_DEVICE_INFO);
@@ -2983,8 +2984,9 @@ _dm_resize_partition (PedDisk* disk, const PedPartition* part)
         /* device-mapper uses 512b units, not the device's sector size */
         dm_task_add_target (task, 0, part->geom.length * (disk->dev->sector_size / PED_SECTOR_SIZE_DEFAULT),
                 "linear", params);
-        if (!dm_task_set_cookie (task, &cookie, 0))
-                goto err;
+        /* NOTE: DM_DEVICE_RELOAD doesn't generate udev events, so no cookie is needed (it will freeze).
+         *       DM_DEVICE_RESUME does, so get a cookie and synchronize with udev.
+         */
         if (dm_task_run (task)) {
                 dm_task_destroy (task);
                 task = dm_task_create (DM_DEVICE_RESUME);
@@ -2993,10 +2995,8 @@ _dm_resize_partition (PedDisk* disk, const PedPartition* part)
                 dm_task_set_name (task, vol_name);
                 if (!dm_task_set_cookie (task, &cookie, 0))
                         goto err;
-                if (dm_task_run (task)) {
-                        free (params);
-                        free (vol_name);
-                        return 1;
+                if (_dm_task_run_wait (task, cookie)) {
+                        rc = 1;
                 }
         }
 err:
@@ -3005,7 +3005,7 @@ err:
                 dm_task_destroy (task);
         free (params);
         free (vol_name);
-        return 0;
+        return rc;
 }
 
 #endif
-- 
2.9.4