From: Julian Anastasov ja@ssi.bg
[ Upstream commit cf47a0b882a4e5f6b34c7949d7b293e9287f1972 ]
syzkaller reports for memory leak when registering hooks [1]
As we moved the nf_unregister_net_hooks() call into __ip_vs_dev_cleanup(), defer the nf_register_net_hooks() call, so that hooks are allocated and freed from same pernet_operations (ipvs_core_dev_ops).
[1] BUG: memory leak unreferenced object 0xffff88810acd8a80 (size 96): comm "syz-executor073", pid 7254, jiffies 4294950560 (age 22.250s) hex dump (first 32 bytes): 02 00 00 00 00 00 00 00 50 8b bb 82 ff ff ff ff ........P....... 00 00 00 00 00 00 00 00 00 77 bb 82 ff ff ff ff .........w...... backtrace: [<0000000013db61f1>] kmemleak_alloc_recursive include/linux/kmemleak.h:55 [inline] [<0000000013db61f1>] slab_post_alloc_hook mm/slab.h:439 [inline] [<0000000013db61f1>] slab_alloc_node mm/slab.c:3269 [inline] [<0000000013db61f1>] kmem_cache_alloc_node_trace+0x15b/0x2a0 mm/slab.c:3597 [<000000001a27307d>] __do_kmalloc_node mm/slab.c:3619 [inline] [<000000001a27307d>] __kmalloc_node+0x38/0x50 mm/slab.c:3627 [<0000000025054add>] kmalloc_node include/linux/slab.h:590 [inline] [<0000000025054add>] kvmalloc_node+0x4a/0xd0 mm/util.c:431 [<0000000050d1bc00>] kvmalloc include/linux/mm.h:637 [inline] [<0000000050d1bc00>] kvzalloc include/linux/mm.h:645 [inline] [<0000000050d1bc00>] allocate_hook_entries_size+0x3b/0x60 net/netfilter/core.c:61 [<00000000e8abe142>] nf_hook_entries_grow+0xae/0x270 net/netfilter/core.c:128 [<000000004b94797c>] __nf_register_net_hook+0x9a/0x170 net/netfilter/core.c:337 [<00000000d1545cbc>] nf_register_net_hook+0x34/0xc0 net/netfilter/core.c:464 [<00000000876c9b55>] nf_register_net_hooks+0x53/0xc0 net/netfilter/core.c:480 [<000000002ea868e0>] __ip_vs_init+0xe8/0x170 net/netfilter/ipvs/ip_vs_core.c:2280 [<000000002eb2d451>] ops_init+0x4c/0x140 net/core/net_namespace.c:130 [<000000000284ec48>] setup_net+0xde/0x230 net/core/net_namespace.c:316 [<00000000a70600fa>] copy_net_ns+0xf0/0x1e0 net/core/net_namespace.c:439 [<00000000ff26c15e>] create_new_namespaces+0x141/0x2a0 kernel/nsproxy.c:107 [<00000000b103dc79>] copy_namespaces+0xa1/0xe0 kernel/nsproxy.c:165 [<000000007cc008a2>] copy_process.part.0+0x11fd/0x2150 kernel/fork.c:2035 [<00000000c344af7c>] copy_process kernel/fork.c:1800 [inline] [<00000000c344af7c>] _do_fork+0x121/0x4f0 kernel/fork.c:2369
Reported-by: syzbot+722da59ccb264bc19910@syzkaller.appspotmail.com Fixes: 719c7d563c17 ("ipvs: Fix use-after-free in ip_vs_in") Signed-off-by: Julian Anastasov ja@ssi.bg Acked-by: Simon Horman horms@verge.net.au Signed-off-by: Pablo Neira Ayuso pablo@netfilter.org Signed-off-by: Sasha Levin sashal@kernel.org --- net/netfilter/ipvs/ip_vs_core.c | 21 ++++++++++++++------- 1 file changed, 14 insertions(+), 7 deletions(-)
diff --git a/net/netfilter/ipvs/ip_vs_core.c b/net/netfilter/ipvs/ip_vs_core.c index 7138556b206b..d5103a9eb302 100644 --- a/net/netfilter/ipvs/ip_vs_core.c +++ b/net/netfilter/ipvs/ip_vs_core.c @@ -2245,7 +2245,6 @@ static const struct nf_hook_ops ip_vs_ops[] = { static int __net_init __ip_vs_init(struct net *net) { struct netns_ipvs *ipvs; - int ret;
ipvs = net_generic(net, ip_vs_net_id); if (ipvs == NULL) @@ -2277,17 +2276,11 @@ static int __net_init __ip_vs_init(struct net *net) if (ip_vs_sync_net_init(ipvs) < 0) goto sync_fail;
- ret = nf_register_net_hooks(net, ip_vs_ops, ARRAY_SIZE(ip_vs_ops)); - if (ret < 0) - goto hook_fail; - return 0; /* * Error handling */
-hook_fail: - ip_vs_sync_net_cleanup(ipvs); sync_fail: ip_vs_conn_net_cleanup(ipvs); conn_fail: @@ -2317,6 +2310,19 @@ static void __net_exit __ip_vs_cleanup(struct net *net) net->ipvs = NULL; }
+static int __net_init __ip_vs_dev_init(struct net *net) +{ + int ret; + + ret = nf_register_net_hooks(net, ip_vs_ops, ARRAY_SIZE(ip_vs_ops)); + if (ret < 0) + goto hook_fail; + return 0; + +hook_fail: + return ret; +} + static void __net_exit __ip_vs_dev_cleanup(struct net *net) { struct netns_ipvs *ipvs = net_ipvs(net); @@ -2336,6 +2342,7 @@ static struct pernet_operations ipvs_core_ops = { };
static struct pernet_operations ipvs_core_dev_ops = { + .init = __ip_vs_dev_init, .exit = __ip_vs_dev_cleanup, };