diff options
| author | Zhengchao Shao <shaozhengchao@huawei.com> | 2022-10-20 10:42:13 +0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2022-10-24 12:40:06 +0100 |
| commit | d266935ac43d57586e311a087510fe6a084af742 (patch) | |
| tree | eed63f9af216ac15a339f70a83c3a9a15cb8d55b /net | |
| parent | c5884ef477b405aadf49419a417d62dc8137e7f3 (diff) | |
net: fix UAF issue in nfqnl_nf_hook_drop() when ops_init() failed
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>
Diffstat (limited to 'net')
| -rw-r--r-- | net/core/net_namespace.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c index 0ec2f5906a27..f64654df71a2 100644 --- a/net/core/net_namespace.c +++ b/net/core/net_namespace.c @@ -117,6 +117,7 @@ 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; @@ -135,7 +136,13 @@ 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: |