| Message ID | 20221020024213.264324-1-shaozhengchao@huawei.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | d266935ac43d57586e311a087510fe6a084af742 |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net] net: fix UAF issue in nfqnl_nf_hook_drop() when ops_init() failed | expand |
| Context | Check | Description |
|---|---|---|
| netdev/tree_selection | success | Clearly marked for net |
| netdev/fixes_present | success | Fixes tag present in non-next series |
| netdev/subject_prefix | success | Link |
| netdev/cover_letter | success | Single patches do not need cover letters |
| netdev/patch_count | success | Link |
| netdev/header_inline | success | No static functions without inline keyword in header files |
| netdev/build_32bit | success | Errors and warnings before: 2 this patch: 2 |
| netdev/cc_maintainers | success | CCed 10 of 10 maintainers |
| netdev/build_clang | success | Errors and warnings before: 5 this patch: 5 |
| netdev/module_param | success | Was 0 now: 0 |
| netdev/verify_signedoff | success | Signed-off-by tag matches author and committer |
| netdev/check_selftest | success | No net selftest shell script |
| netdev/verify_fixes | success | Fixes tag looks correct |
| netdev/build_allmodconfig_warn | success | Errors and warnings before: 2 this patch: 2 |
| netdev/checkpatch | warning | WARNING: line length of 83 exceeds 80 columns |
| netdev/kdoc | success | Errors and warnings before: 0 this patch: 0 |
| netdev/source_inline | success | Was 0 now: 0 |
Hello: This patch was applied to netdev/net.git (master) by David S. Miller <davem@davemloft.net>: On Thu, 20 Oct 2022 10:42:13 +0800 you wrote: > 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 > > [...] Here is the summary with links: - [net] net: fix UAF issue in nfqnl_nf_hook_drop() when ops_init() failed https://git.kernel.org/netdev/net/c/d266935ac43d You are awesome, thank you!
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:
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> --- net/core/net_namespace.c | 7 +++++++ 1 file changed, 7 insertions(+)