[sr-dev] git:4.1:0e550eec: dtrie: Set child to NULL when run out of SHM

[Stefan Mititelu]

Module: kamailio
Branch: 4.1
Commit: 0e550eec214f9bfea1e87519e6c842230a552e50
URL: https://github.com/kamailio/kamailio/commit/0e550eec214f9bfea1e87519e6c842230a552e50

Author: Stefan Mititelu <stefan.mititelu at 1and1.ro>
Committer: Stefan Mititelu <stefan.mititelu at 1and1.ro>
Date: 2015-08-11T15:42:56+03:00

dtrie: Set child to NULL when run out of SHM

The stop condition in dtrie_delete is node==NULL. Suppose the case when there
is no SHM memory left when trying to dtrie_insert(). The memory gets freed
by shm_free() but the pointer still points to it. This leads to segfault when
dtrie_delete tries to access that memory zone, in the given case. GDB says:
"Cannot access memory at address 0x1130000001d"

(cherry picked from commit 60ffee9cf54ff362026497036935746c9dbe62e5)

---

Modified: lib/trie/dtrie.c

---

Diff:  https://github.com/kamailio/kamailio/commit/0e550eec214f9bfea1e87519e6c842230a552e50.diff
Patch: https://github.com/kamailio/kamailio/commit/0e550eec214f9bfea1e87519e6c842230a552e50.patch

---

diff --git a/lib/trie/dtrie.c b/lib/trie/dtrie.c
index 90cb52f..783f6e7 100644
--- a/lib/trie/dtrie.c
+++ b/lib/trie/dtrie.c
@@ -152,6 +152,7 @@ int dtrie_insert(struct dtrie_node_t *root, const char *number, const unsigned i
 			if(node->child[digit]->child == NULL){
 				SHM_MEM_ERROR;
 				shm_free(node->child[digit]);
+				node->child[digit] = NULL;
 				return -1;
 			}
 			LM_DBG("allocate %lu bytes for %d root children pointer at %p\n",