[PATCH] dccp: Fix possible memleak in dccp_init and dccp_fini

[PATCH] dccp: Fix possible memleak in dccp_init and dccp_fini

[Wang Hai]

There are some memory leaks in dccp_init() and dccp_fini().

In dccp_fini() and the error handling path in dccp_init(), free lhash2
is missing. Add inet_hashinfo2_free_mod() to do it.

If inet_hashinfo2_init_mod() failed in dccp_init(),
percpu_counter_destroy() should be called to destroy dccp_orphan_count.
It need to goto out_free_percpu when inet_hashinfo2_init_mod() failed.

Fixes: c92c81df93df ("net: dccp: fix kernel crash on module load")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wang Hai <wanghai38@huawei.com>
---
 include/net/inet_hashtables.h | 6 ++++++
 net/dccp/proto.c              | 7 +++++--
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/include/net/inet_hashtables.h b/include/net/inet_hashtables.h
index ad64ba6..9256097 100644
--- a/include/net/inet_hashtables.h
+++ b/include/net/inet_hashtables.h
@@ -185,6 +185,12 @@ static inline spinlock_t *inet_ehash_lockp(
 
 int inet_ehash_locks_alloc(struct inet_hashinfo *hashinfo);
 
+static inline void inet_hashinfo2_free_mod(struct inet_hashinfo *h)
+{
+	kfree(h->lhash2);
+	h->lhash2 = NULL;
+}
+
 static inline void inet_ehash_locks_free(struct inet_hashinfo *hashinfo)
 {
 	kvfree(hashinfo->ehash_locks);
diff --git a/net/dccp/proto.c b/net/dccp/proto.c
index 4af8a98..c13b660 100644
--- a/net/dccp/proto.c
+++ b/net/dccp/proto.c
@@ -1139,14 +1139,14 @@ static int __init dccp_init(void)
 	inet_hashinfo_init(&dccp_hashinfo);
 	rc = inet_hashinfo2_init_mod(&dccp_hashinfo);
 	if (rc)
-		goto out_fail;
+		goto out_free_percpu;
 	rc = -ENOBUFS;
 	dccp_hashinfo.bind_bucket_cachep =
 		kmem_cache_create("dccp_bind_bucket",
 				  sizeof(struct inet_bind_bucket), 0,
 				  SLAB_HWCACHE_ALIGN, NULL);
 	if (!dccp_hashinfo.bind_bucket_cachep)
-		goto out_free_percpu;
+		goto out_free_hashinfo2;
 
 	/*
 	 * Size and allocate the main established and bind bucket
@@ -1242,6 +1242,8 @@ static int __init dccp_init(void)
 	free_pages((unsigned long)dccp_hashinfo.ehash, ehash_order);
 out_free_bind_bucket_cachep:
 	kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
+out_free_hashinfo2:
+	inet_hashinfo2_free_mod(&dccp_hashinfo);
 out_free_percpu:
 	percpu_counter_destroy(&dccp_orphan_count);
 out_fail:
@@ -1265,6 +1267,7 @@ static void __exit dccp_fini(void)
 	kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
 	dccp_ackvec_exit();
 	dccp_sysctl_exit();
+	inet_hashinfo2_free_mod(&dccp_hashinfo);
 	percpu_counter_destroy(&dccp_orphan_count);
 }
 
-- 
1.8.3.1

Re: [PATCH] dccp: Fix possible memleak in dccp_init and dccp_fini

[David Miller]

From: Wang Hai <wanghai38@huawei.com>
Date: Tue, 9 Jun 2020 22:18:16 +0800

> There are some memory leaks in dccp_init() and dccp_fini().
> 
> In dccp_fini() and the error handling path in dccp_init(), free lhash2
> is missing. Add inet_hashinfo2_free_mod() to do it.
> 
> If inet_hashinfo2_init_mod() failed in dccp_init(),
> percpu_counter_destroy() should be called to destroy dccp_orphan_count.
> It need to goto out_free_percpu when inet_hashinfo2_init_mod() failed.
> 
> Fixes: c92c81df93df ("net: dccp: fix kernel crash on module load")
> Reported-by: Hulk Robot <hulkci@huawei.com>
> Signed-off-by: Wang Hai <wanghai38@huawei.com>

Applied and queued up for -stable, thank you.