From 0f5907af39137f8183ed536aaa00f322d7365130 Mon Sep 17 00:00:00 2001 From: Miaohe Lin Date: Mon, 10 Aug 2020 08:16:58 -0400 Subject: net: Fix potential memory leak in proto_register() If we failed to assign proto idx, we free the twsk_slab_name but forget to free the twsk_slab. Add a helper function tw_prot_cleanup() to free these together and also use this helper function in proto_unregister(). Fixes: b45ce32135d1 ("sock: fix potential memory leak in proto_register()") Signed-off-by: Miaohe Lin Signed-off-by: David S. Miller --- net/core/sock.c | 25 +++++++++++++++---------- 1 file changed, 15 insertions(+), 10 deletions(-) (limited to 'net/core') diff --git a/net/core/sock.c b/net/core/sock.c index 49cd5ffe673e..c9083ad44ea1 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -3406,6 +3406,16 @@ static void sock_inuse_add(struct net *net, int val) } #endif +static void tw_prot_cleanup(struct timewait_sock_ops *twsk_prot) +{ + if (!twsk_prot) + return; + kfree(twsk_prot->twsk_slab_name); + twsk_prot->twsk_slab_name = NULL; + kmem_cache_destroy(twsk_prot->twsk_slab); + twsk_prot->twsk_slab = NULL; +} + static void req_prot_cleanup(struct request_sock_ops *rsk_prot) { if (!rsk_prot) @@ -3476,7 +3486,7 @@ int proto_register(struct proto *prot, int alloc_slab) prot->slab_flags, NULL); if (prot->twsk_prot->twsk_slab == NULL) - goto out_free_timewait_sock_slab_name; + goto out_free_timewait_sock_slab; } } @@ -3484,15 +3494,15 @@ int proto_register(struct proto *prot, int alloc_slab) ret = assign_proto_idx(prot); if (ret) { mutex_unlock(&proto_list_mutex); - goto out_free_timewait_sock_slab_name; + goto out_free_timewait_sock_slab; } list_add(&prot->node, &proto_list); mutex_unlock(&proto_list_mutex); return ret; -out_free_timewait_sock_slab_name: +out_free_timewait_sock_slab: if (alloc_slab && prot->twsk_prot) - kfree(prot->twsk_prot->twsk_slab_name); + tw_prot_cleanup(prot->twsk_prot); out_free_request_sock_slab: if (alloc_slab) { req_prot_cleanup(prot->rsk_prot); @@ -3516,12 +3526,7 @@ void proto_unregister(struct proto *prot) prot->slab = NULL; req_prot_cleanup(prot->rsk_prot); - - if (prot->twsk_prot != NULL && prot->twsk_prot->twsk_slab != NULL) { - kmem_cache_destroy(prot->twsk_prot->twsk_slab); - kfree(prot->twsk_prot->twsk_slab_name); - prot->twsk_prot->twsk_slab = NULL; - } + tw_prot_cleanup(prot->twsk_prot); } EXPORT_SYMBOL(proto_unregister); -- cgit v1.2.3