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

From: Wang Hai
Date: Tue Jun 09 2020 - 10:19:02 EST


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@xxxxxxxxxx>
Signed-off-by: Wang Hai <wanghai38@xxxxxxxxxx>
---
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