net: tls: fix possible race condition between do_tls_getsockopt_conf() and do_tls_set...

ctx->crypto_send.info is not protected by lock_sock in
do_tls_getsockopt_conf(). A race condition between do_tls_getsockopt_conf()
and error paths of do_tls_setsockopt_conf() may lead to a use-after-free
or null-deref.

More discussion:  https://lore.kernel.org/all/Y/ht6gQL+u6fj3dG@hog/

Fixes: 3c4d7559159b ("tls: kernel TLS support")
Signed-off-by: Hangyu Hua <hbh25y@gmail.com>
Link: https://lore.kernel.org/r/20230228023344.9623-1-hbh25y@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/net/tls/tls_main.c b/net/tls/tls_main.c
index 3735cb0..b32c112 100644 (file)
--- a/net/tls/tls_main.c
+++ b/net/tls/tls_main.c
@@ -405,13 +405,11 @@ static int do_tls_getsockopt_conf(struct sock *sk, char __user *optval,
                        rc = -EINVAL;
                        goto out;
                }
-               lock_sock(sk);
                memcpy(crypto_info_aes_gcm_128->iv,
                       cctx->iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE,
                       TLS_CIPHER_AES_GCM_128_IV_SIZE);
                memcpy(crypto_info_aes_gcm_128->rec_seq, cctx->rec_seq,
                       TLS_CIPHER_AES_GCM_128_REC_SEQ_SIZE);
-               release_sock(sk);
                if (copy_to_user(optval,
                                 crypto_info_aes_gcm_128,
                                 sizeof(*crypto_info_aes_gcm_128)))
@@ -429,13 +427,11 @@ static int do_tls_getsockopt_conf(struct sock *sk, char __user *optval,
                        rc = -EINVAL;
                        goto out;
                }
-               lock_sock(sk);
                memcpy(crypto_info_aes_gcm_256->iv,
                       cctx->iv + TLS_CIPHER_AES_GCM_256_SALT_SIZE,
                       TLS_CIPHER_AES_GCM_256_IV_SIZE);
                memcpy(crypto_info_aes_gcm_256->rec_seq, cctx->rec_seq,
                       TLS_CIPHER_AES_GCM_256_REC_SEQ_SIZE);
-               release_sock(sk);
                if (copy_to_user(optval,
                                 crypto_info_aes_gcm_256,
                                 sizeof(*crypto_info_aes_gcm_256)))
@@ -451,13 +447,11 @@ static int do_tls_getsockopt_conf(struct sock *sk, char __user *optval,
                        rc = -EINVAL;
                        goto out;
                }
-               lock_sock(sk);
                memcpy(aes_ccm_128->iv,
                       cctx->iv + TLS_CIPHER_AES_CCM_128_SALT_SIZE,
                       TLS_CIPHER_AES_CCM_128_IV_SIZE);
                memcpy(aes_ccm_128->rec_seq, cctx->rec_seq,
                       TLS_CIPHER_AES_CCM_128_REC_SEQ_SIZE);
-               release_sock(sk);
                if (copy_to_user(optval, aes_ccm_128, sizeof(*aes_ccm_128)))
                        rc = -EFAULT;
                break;
@@ -472,13 +466,11 @@ static int do_tls_getsockopt_conf(struct sock *sk, char __user *optval,
                        rc = -EINVAL;
                        goto out;
                }
-               lock_sock(sk);
                memcpy(chacha20_poly1305->iv,
                       cctx->iv + TLS_CIPHER_CHACHA20_POLY1305_SALT_SIZE,
                       TLS_CIPHER_CHACHA20_POLY1305_IV_SIZE);
                memcpy(chacha20_poly1305->rec_seq, cctx->rec_seq,
                       TLS_CIPHER_CHACHA20_POLY1305_REC_SEQ_SIZE);
-               release_sock(sk);
                if (copy_to_user(optval, chacha20_poly1305,
                                sizeof(*chacha20_poly1305)))
                        rc = -EFAULT;
@@ -493,13 +485,11 @@ static int do_tls_getsockopt_conf(struct sock *sk, char __user *optval,
                        rc = -EINVAL;
                        goto out;
                }
-               lock_sock(sk);
                memcpy(sm4_gcm_info->iv,
                       cctx->iv + TLS_CIPHER_SM4_GCM_SALT_SIZE,
                       TLS_CIPHER_SM4_GCM_IV_SIZE);
                memcpy(sm4_gcm_info->rec_seq, cctx->rec_seq,
                       TLS_CIPHER_SM4_GCM_REC_SEQ_SIZE);
-               release_sock(sk);
                if (copy_to_user(optval, sm4_gcm_info, sizeof(*sm4_gcm_info)))
                        rc = -EFAULT;
                break;
@@ -513,13 +503,11 @@ static int do_tls_getsockopt_conf(struct sock *sk, char __user *optval,
                        rc = -EINVAL;
                        goto out;
                }
-               lock_sock(sk);
                memcpy(sm4_ccm_info->iv,
                       cctx->iv + TLS_CIPHER_SM4_CCM_SALT_SIZE,
                       TLS_CIPHER_SM4_CCM_IV_SIZE);
                memcpy(sm4_ccm_info->rec_seq, cctx->rec_seq,
                       TLS_CIPHER_SM4_CCM_REC_SEQ_SIZE);
-               release_sock(sk);
                if (copy_to_user(optval, sm4_ccm_info, sizeof(*sm4_ccm_info)))
                        rc = -EFAULT;
                break;
@@ -535,13 +523,11 @@ static int do_tls_getsockopt_conf(struct sock *sk, char __user *optval,
                        rc = -EINVAL;
                        goto out;
                }
-               lock_sock(sk);
                memcpy(crypto_info_aria_gcm_128->iv,
                       cctx->iv + TLS_CIPHER_ARIA_GCM_128_SALT_SIZE,
                       TLS_CIPHER_ARIA_GCM_128_IV_SIZE);
                memcpy(crypto_info_aria_gcm_128->rec_seq, cctx->rec_seq,
                       TLS_CIPHER_ARIA_GCM_128_REC_SEQ_SIZE);
-               release_sock(sk);
                if (copy_to_user(optval,
                                 crypto_info_aria_gcm_128,
                                 sizeof(*crypto_info_aria_gcm_128)))
@@ -559,13 +545,11 @@ static int do_tls_getsockopt_conf(struct sock *sk, char __user *optval,
                        rc = -EINVAL;
                        goto out;
                }
-               lock_sock(sk);
                memcpy(crypto_info_aria_gcm_256->iv,
                       cctx->iv + TLS_CIPHER_ARIA_GCM_256_SALT_SIZE,
                       TLS_CIPHER_ARIA_GCM_256_IV_SIZE);
                memcpy(crypto_info_aria_gcm_256->rec_seq, cctx->rec_seq,
                       TLS_CIPHER_ARIA_GCM_256_REC_SEQ_SIZE);
-               release_sock(sk);
                if (copy_to_user(optval,
                                 crypto_info_aria_gcm_256,
                                 sizeof(*crypto_info_aria_gcm_256)))
@@ -614,11 +598,9 @@ static int do_tls_getsockopt_no_pad(struct sock *sk, char __user *optval,
        if (len < sizeof(value))
                return -EINVAL;
 
-       lock_sock(sk);
        value = -EINVAL;
        if (ctx->rx_conf == TLS_SW || ctx->rx_conf == TLS_HW)
                value = ctx->rx_no_pad;
-       release_sock(sk);
        if (value < 0)
                return value;
 
@@ -635,6 +617,8 @@ static int do_tls_getsockopt(struct sock *sk, int optname,
 {
        int rc = 0;
 
+       lock_sock(sk);
+
        switch (optname) {
        case TLS_TX:
        case TLS_RX:
@@ -651,6 +635,9 @@ static int do_tls_getsockopt(struct sock *sk, int optname,
                rc = -ENOPROTOOPT;
                break;
        }
+
+       release_sock(sk);
+
        return rc;
 }