Messages in this thread | | | Date | Fri, 24 Feb 2023 11:33:29 +0800 | Subject | Re: [PATCH] net: tls: fix possible info leak in tls_set_device_offload() | From | Hangyu Hua <> |
| |
On 24/2/2023 11:07, Hangyu Hua wrote: > On 23/2/2023 19:15, Sabrina Dubroca wrote: >> 2023-02-23, 17:05:08 +0800, Hangyu Hua wrote: >>> After tls_set_device_offload() fails, we enter tls_set_sw_offload(). But >>> tls_set_sw_offload can't set cctx->iv and cctx->rec_seq to NULL if it >>> fails >>> before kmalloc cctx->iv. This may cause info leak when we call >>> do_tls_getsockopt_conf(). >> >> Is there really an issue here? >> >> If both tls_set_device_offload and tls_set_sw_offload fail, >> do_tls_setsockopt_conf will clear crypto_{send,recv} from the context. >> Then the TLS_CRYPTO_INFO_READY in do_tls_getsockopt_conf will fail, so >> we won't try to access iv or rec_seq. >> > > My bad. I forget memzero_explicit. Then this is harmless. But I still > think it is better to set them to NULL like tls_set_sw_offload's error > path because we don't know there are another way to do this(I will > change the commit log). What do you think?
Like a rare case, there is a race condition between do_tls_getsockopt_conf and do_tls_setsockopt_conf while the previous condition is met. TLS_CRYPTO_INFO_READY(crypto_info) is not protected by lock_sock in do_tls_getsockopt_conf. It's just too difficult to satisfy both conditions at the same time.
| |