Patch "net: tls: fix possible race condition between do_tls_getsockopt_conf() and do_tls_setsockopt_conf()" has been added to the 5.4-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

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

to the 5.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     net-tls-fix-possible-race-condition-between-do_tls_g.patch
and it can be found in the queue-5.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 4192ca1e3230eaee9b9d87b0344db99063701946
Author: Hangyu Hua <hbh25y@xxxxxxxxx>
Date:   Thu Mar 23 05:30:32 2023 +0000

    net: tls: fix possible race condition between do_tls_getsockopt_conf() and do_tls_setsockopt_conf()
    
    commit 49c47cc21b5b7a3d8deb18fc57b0aa2ab1286962 upstream.
    
    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@xxxxxxxxx>
    Link: https://lore.kernel.org/r/20230228023344.9623-1-hbh25y@xxxxxxxxx
    Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
    Signed-off-by: Meena Shanmugam <meenashanmugam@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/net/tls/tls_main.c b/net/tls/tls_main.c
index 7aba4ee77aba3..cb51a2f46b11d 100644
--- a/net/tls/tls_main.c
+++ b/net/tls/tls_main.c
@@ -371,13 +371,11 @@ static int do_tls_getsockopt_tx(struct sock *sk, char __user *optval,
 			rc = -EINVAL;
 			goto out;
 		}
-		lock_sock(sk);
 		memcpy(crypto_info_aes_gcm_128->iv,
 		       ctx->tx.iv + TLS_CIPHER_AES_GCM_128_SALT_SIZE,
 		       TLS_CIPHER_AES_GCM_128_IV_SIZE);
 		memcpy(crypto_info_aes_gcm_128->rec_seq, ctx->tx.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)))
@@ -395,13 +393,11 @@ static int do_tls_getsockopt_tx(struct sock *sk, char __user *optval,
 			rc = -EINVAL;
 			goto out;
 		}
-		lock_sock(sk);
 		memcpy(crypto_info_aes_gcm_256->iv,
 		       ctx->tx.iv + TLS_CIPHER_AES_GCM_256_SALT_SIZE,
 		       TLS_CIPHER_AES_GCM_256_IV_SIZE);
 		memcpy(crypto_info_aes_gcm_256->rec_seq, ctx->tx.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)))
@@ -421,6 +417,8 @@ static int do_tls_getsockopt(struct sock *sk, int optname,
 {
 	int rc = 0;
 
+	lock_sock(sk);
+
 	switch (optname) {
 	case TLS_TX:
 		rc = do_tls_getsockopt_tx(sk, optval, optlen);
@@ -429,6 +427,9 @@ static int do_tls_getsockopt(struct sock *sk, int optname,
 		rc = -ENOPROTOOPT;
 		break;
 	}
+
+	release_sock(sk);
+
 	return rc;
 }