Commit 5c5d22a7 authored Jan 10, 2020 by Jakub Kicinski Committed by David S. Miller Jan 10, 2020

net/tls: avoid spurious decryption error with HW resync



When device loses sync mid way through a record - kernel
has to re-encrypt the part of the record which the device
already decrypted to be able to decrypt and authenticate
the record in its entirety.

The re-encryption piggy backs on the decryption routine,
but obviously because the partially decrypted record can't
be authenticated crypto API returns an error which is then
ignored by tls_device_reencrypt().

Commit 5c5ec668 ("net/tls: add TlsDecryptError stat")
added a statistic to count decryption errors, this statistic
can't be incremented when we see the expected re-encryption
error. Move the inc to the caller.

Reported-and-tested-by: David Beckett <david.beckett@netronome.com>
Fixes: 5c5ec668 ("net/tls: add TlsDecryptError stat")
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent e267371d

net/tls/tls_sw.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -256,8 +256,6 @@ static int tls_do_decryption(struct sock *sk,
		return ret;

		ret = crypto_wait_req(ret, &ctx->async_wait);
		} else if (ret == -EBADMSG) {
		TLS_INC_STATS(sock_net(sk), LINUX_MIB_TLSDECRYPTERROR);
		}

		if (async)
		@@ -1515,7 +1513,9 @@ static int decrypt_skb_update(struct sock sk, struct sk_buff skb,
		if (err == -EINPROGRESS)
		tls_advance_record_sn(sk, prot,
		&tls_ctx->rx);

		else if (err == -EBADMSG)
		TLS_INC_STATS(sock_net(sk),
		LINUX_MIB_TLSDECRYPTERROR);
		return err;
		}
		} else {

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