netdev - [PATCH net 2/3] net/tls: fix state removal with feature flags off

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Tue, 21 May 2019 19:02:01 -0700
From:   Jakub Kicinski <jakub.kicinski@...ronome.com>
To:     davem@...emloft.net
Cc:     netdev@...r.kernel.org, oss-drivers@...ronome.com,
        borisp@...lanox.com, alexei.starovoitov@...il.com,
        Jakub Kicinski <jakub.kicinski@...ronome.com>,
        Dirk van der Merwe <dirk.vandermerwe@...ronome.com>
Subject: [PATCH net 2/3] net/tls: fix state removal with feature flags off

TLS offload drivers shouldn't (and currently don't) block
the TLS offload feature changes based on whether there are
active offloaded connections or not.

This seems to be a good idea, because we want the admin to
be able to disable the TLS offload at any time, and there
is no clean way of disabling it for active connections
(TX side is quite problematic).  So if features are cleared
existing connections will stay offloaded until they close,
and new connections will not attempt offload to a given
device.

However, the offload state removal handling is currently
broken if feature flags get cleared while there are
active TLS offloads.

RX side will completely bail from cleanup, even on normal
remove path, leaving device state dangling, potentially
causing issues when the 5-tuple is reused.  It will also
fail to release the netdev reference.

Remove the RX-side warning message, in next release cycle
it should be printed when features are disabled, rather
than when connection dies, but for that we need a more
efficient method of finding connection of a given netdev
(a'la BPF offload code).

Fixes: 4799ac81e52a ("tls: Add rx inline crypto offload")
Signed-off-by: Jakub Kicinski <jakub.kicinski@...ronome.com>
Reviewed-by: Dirk van der Merwe <dirk.vandermerwe@...ronome.com>
---
 net/tls/tls_device.c | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/net/tls/tls_device.c b/net/tls/tls_device.c
index aa33e4accc32..07650446e892 100644
--- a/net/tls/tls_device.c
+++ b/net/tls/tls_device.c
@@ -939,12 +939,6 @@ void tls_device_offload_cleanup_rx(struct sock *sk)
 	if (!netdev)
 		goto out;

-	if (!(netdev->features & NETIF_F_HW_TLS_RX)) {
-		pr_err_ratelimited("%s: device is missing NETIF_F_HW_TLS_RX cap\n",
-				   __func__);
-		goto out;
-	}
-
 	netdev->tlsdev_ops->tls_dev_del(netdev, tls_ctx,
 					TLS_OFFLOAD_CTX_DIR_RX);

-- 
2.21.0