z3fold: fix memory leak

In z3fold_create_pool(), the memory allocated by __alloc_percpu() is not
released on the error path that pool->compact_wq , which holds the
return value of create_singlethread_workqueue(), is NULL.  This will
result in a memory leak bug.

[akpm@linux-foundation.org: fix oops on kzalloc() failure, check __alloc_percpu() retval]
Link: http://lkml.kernel.org/r/1522803111-29209-1-git-send-email-wangxidong_97@163.com
Signed-off-by: Xidong Wang <wangxidong_97@163.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Vitaly Wool <vitalywool@gmail.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/z3fold.c b/mm/z3fold.c
index f579ad4..c6b1fb0 100644 (file)
--- a/mm/z3fold.c
+++ b/mm/z3fold.c
@@ -467,6 +467,8 @@ static struct z3fold_pool *z3fold_create_pool(const char *name, gfp_t gfp,
        spin_lock_init(&pool->lock);
        spin_lock_init(&pool->stale_lock);
        pool->unbuddied = __alloc_percpu(sizeof(struct list_head)*NCHUNKS, 2);
+       if (!pool->unbuddied)
+               goto out_pool;
        for_each_possible_cpu(cpu) {
                struct list_head *unbuddied =
                                per_cpu_ptr(pool->unbuddied, cpu);
@@ -479,7 +481,7 @@ static struct z3fold_pool *z3fold_create_pool(const char *name, gfp_t gfp,
        pool->name = name;
        pool->compact_wq = create_singlethread_workqueue(pool->name);
        if (!pool->compact_wq)
-               goto out;
+               goto out_unbuddied;
        pool->release_wq = create_singlethread_workqueue(pool->name);
        if (!pool->release_wq)
                goto out_wq;
@@ -489,8 +491,11 @@ static struct z3fold_pool *z3fold_create_pool(const char *name, gfp_t gfp,
 
 out_wq:
        destroy_workqueue(pool->compact_wq);
-out:
+out_unbuddied:
+       free_percpu(pool->unbuddied);
+out_pool:
        kfree(pool);
+out:
        return NULL;
 }