From: Zhengchao Shao shaozhengchao@huawei.com
[ Upstream commit d266935ac43d57586e311a087510fe6a084af742 ]
When the ops_init() interface is invoked to initialize the net, but ops->init() fails, data is released. However, the ptr pointer in net->gen is invalid. In this case, when nfqnl_nf_hook_drop() is invoked to release the net, invalid address access occurs.
The process is as follows: setup_net() ops_init() data = kzalloc(...) ---> alloc "data" net_assign_generic() ---> assign "date" to ptr in net->gen ... ops->init() ---> failed ... kfree(data); ---> ptr in net->gen is invalid ... ops_exit_list() ... nfqnl_nf_hook_drop() *q = nfnl_queue_pernet(net) ---> q is invalid
The following is the Call Trace information: BUG: KASAN: use-after-free in nfqnl_nf_hook_drop+0x264/0x280 Read of size 8 at addr ffff88810396b240 by task ip/15855 Call Trace: <TASK> dump_stack_lvl+0x8e/0xd1 print_report+0x155/0x454 kasan_report+0xba/0x1f0 nfqnl_nf_hook_drop+0x264/0x280 nf_queue_nf_hook_drop+0x8b/0x1b0 __nf_unregister_net_hook+0x1ae/0x5a0 nf_unregister_net_hooks+0xde/0x130 ops_exit_list+0xb0/0x170 setup_net+0x7ac/0xbd0 copy_net_ns+0x2e6/0x6b0 create_new_namespaces+0x382/0xa50 unshare_nsproxy_namespaces+0xa6/0x1c0 ksys_unshare+0x3a4/0x7e0 __x64_sys_unshare+0x2d/0x40 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 </TASK>
Allocated by task 15855: kasan_save_stack+0x1e/0x40 kasan_set_track+0x21/0x30 __kasan_kmalloc+0xa1/0xb0 __kmalloc+0x49/0xb0 ops_init+0xe7/0x410 setup_net+0x5aa/0xbd0 copy_net_ns+0x2e6/0x6b0 create_new_namespaces+0x382/0xa50 unshare_nsproxy_namespaces+0xa6/0x1c0 ksys_unshare+0x3a4/0x7e0 __x64_sys_unshare+0x2d/0x40 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x46/0xb0
Freed by task 15855: kasan_save_stack+0x1e/0x40 kasan_set_track+0x21/0x30 kasan_save_free_info+0x2a/0x40 ____kasan_slab_free+0x155/0x1b0 slab_free_freelist_hook+0x11b/0x220 __kmem_cache_free+0xa4/0x360 ops_init+0xb9/0x410 setup_net+0x5aa/0xbd0 copy_net_ns+0x2e6/0x6b0 create_new_namespaces+0x382/0xa50 unshare_nsproxy_namespaces+0xa6/0x1c0 ksys_unshare+0x3a4/0x7e0 __x64_sys_unshare+0x2d/0x40 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x46/0xb0
Fixes: f875bae06533 ("net: Automatically allocate per namespace data.") Signed-off-by: Zhengchao Shao shaozhengchao@huawei.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- net/core/net_namespace.c | 7 +++++++ 1 file changed, 7 insertions(+)
diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c index 62a972f04cef..b96df54d0036 100644 --- a/net/core/net_namespace.c +++ b/net/core/net_namespace.c @@ -120,6 +120,7 @@ static int net_assign_generic(struct net *net, unsigned int id, void *data)
static int ops_init(const struct pernet_operations *ops, struct net *net) { + struct net_generic *ng; int err = -ENOMEM; void *data = NULL;
@@ -138,7 +139,13 @@ static int ops_init(const struct pernet_operations *ops, struct net *net) if (!err) return 0;
+ if (ops->id && ops->size) { cleanup: + ng = rcu_dereference_protected(net->gen, + lockdep_is_held(&pernet_ops_rwsem)); + ng->ptr[*ops->id] = NULL; + } + kfree(data);
out: