mm/memory_hotplug.c: add NULL check to avoid potential NULL pointer dereference
The NULL check at line 1226: if (!pgdat), implies that pointer pgdat
might be NULL.
rollback_node_hotadd() dereferences this pointer. Add NULL check to
avoid a potential NULL pointer dereference.
Addresses-Coverity-ID: 1369133
Link: http://lkml.kernel.org/r/20170530212436.GA6195@embeddedgus
Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index f79aac7..7b1311a 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1268,7 +1268,7 @@ int __ref add_memory_resource(int nid, struct resource *res, bool online)
error:
/* rollback pgdat allocation and others */
- if (new_pgdat)
+ if (new_pgdat && pgdat)
rollback_node_hotadd(nid, pgdat);
memblock_remove(start, size);