From 52ee6ef36ee10dd493cf2067311e56ca8015eb8d Mon Sep 17 00:00:00 2001 From: Doron Roberts-Kedes Date: Mon, 2 Jul 2018 10:25:05 -0700 Subject: tls: fix skb_to_sgvec returning unhandled error. The current code does not inspect the return value of skb_to_sgvec. This can cause a nullptr kernel panic when the malformed sgvec is passed into the crypto request. Checking the return value of skb_to_sgvec and skipping decryption if it is negative fixes this problem. Fixes: c46234ebb4d1 ("tls: RX path for ktls") Acked-by: Dave Watson Signed-off-by: Doron Roberts-Kedes Signed-off-by: David S. Miller --- net/tls/tls_sw.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'net/tls') diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c index d2380548f8f6..7818011fd250 100644 --- a/net/tls/tls_sw.c +++ b/net/tls/tls_sw.c @@ -701,6 +701,10 @@ static int decrypt_skb(struct sock *sk, struct sk_buff *skb, nsg = skb_to_sgvec(skb, &sgin[1], rxm->offset + tls_ctx->rx.prepend_size, rxm->full_len - tls_ctx->rx.prepend_size); + if (nsg < 0) { + ret = nsg; + goto out; + } tls_make_aad(ctx->rx_aad_ciphertext, rxm->full_len - tls_ctx->rx.overhead_size, @@ -712,6 +716,7 @@ static int decrypt_skb(struct sock *sk, struct sk_buff *skb, rxm->full_len - tls_ctx->rx.overhead_size, skb, sk->sk_allocation); +out: if (sgin != &sgin_arr[0]) kfree(sgin); -- cgit From 32da12216e467dea70a09cd7094c30779ce0f9db Mon Sep 17 00:00:00 2001 From: Dave Watson Date: Thu, 12 Jul 2018 08:03:43 -0700 Subject: tls: Stricter error checking in zerocopy sendmsg path In the zerocopy sendmsg() path, there are error checks to revert the zerocopy if we get any error code. syzkaller has discovered that tls_push_record can return -ECONNRESET, which is fatal, and happens after the point at which it is safe to revert the iter, as we've already passed the memory to do_tcp_sendpages. Previously this code could return -ENOMEM and we would want to revert the iter, but AFAIK this no longer returns ENOMEM after a447da7d004 ("tls: fix waitall behavior in tls_sw_recvmsg"), so we fail for all error codes. Reported-by: syzbot+c226690f7b3126c5ee04@syzkaller.appspotmail.com Reported-by: syzbot+709f2810a6a05f11d4d3@syzkaller.appspotmail.com Signed-off-by: Dave Watson Fixes: 3c4d7559159b ("tls: kernel TLS support") Signed-off-by: David S. Miller --- net/tls/tls_sw.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net/tls') diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c index 7818011fd250..4618f1c31137 100644 --- a/net/tls/tls_sw.c +++ b/net/tls/tls_sw.c @@ -440,7 +440,7 @@ alloc_encrypted: ret = tls_push_record(sk, msg->msg_flags, record_type); if (!ret) continue; - if (ret == -EAGAIN) + if (ret < 0) goto send_end; copied -= try_to_copy; -- cgit