From 025cc2fb6a4e84e9a0552c0017dcd1c24b7ac7da Mon Sep 17 00:00:00 2001 From: Maxim Mikityanskiy Date: Wed, 25 Nov 2020 14:18:10 -0800 Subject: [PATCH] net/tls: Protect from calling tls_dev_del for TLS RX twice tls_device_offload_cleanup_rx doesn't clear tls_ctx->netdev after calling tls_dev_del if TLX TX offload is also enabled. Clearing tls_ctx->netdev gets postponed until tls_device_gc_task. It leaves a time frame when tls_device_down may get called and call tls_dev_del for RX one extra time, confusing the driver, which may lead to a crash. This patch corrects this racy behavior by adding a flag to prevent tls_device_down from calling tls_dev_del the second time. Fixes: e8f69799810c ("net/tls: Add generic NIC offload infrastructure") Signed-off-by: Maxim Mikityanskiy Signed-off-by: Saeed Mahameed Link: https://lore.kernel.org/r/20201125221810.69870-1-saeedm@nvidia.com Signed-off-by: Jakub Kicinski --- include/net/tls.h | 6 ++++++ net/tls/tls_device.c | 5 ++++- 2 files changed, 10 insertions(+), 1 deletion(-) diff --git a/include/net/tls.h b/include/net/tls.h index cf1473099453..2bdd802212fe 100644 --- a/include/net/tls.h +++ b/include/net/tls.h @@ -199,6 +199,12 @@ enum tls_context_flags { * to be atomic. */ TLS_TX_SYNC_SCHED = 1, + /* tls_dev_del was called for the RX side, device state was released, + * but tls_ctx->netdev might still be kept, because TX-side driver + * resources might not be released yet. Used to prevent the second + * tls_dev_del call in tls_device_down if it happens simultaneously. + */ + TLS_RX_DEV_CLOSED = 2, }; struct cipher_context { diff --git a/net/tls/tls_device.c b/net/tls/tls_device.c index 54d3e161d198..a3ab2d3d4e4e 100644 --- a/net/tls/tls_device.c +++ b/net/tls/tls_device.c @@ -1262,6 +1262,8 @@ void tls_device_offload_cleanup_rx(struct sock *sk) if (tls_ctx->tx_conf != TLS_HW) { dev_put(netdev); tls_ctx->netdev = NULL; + } else { + set_bit(TLS_RX_DEV_CLOSED, &tls_ctx->flags); } out: up_read(&device_offload_lock); @@ -1291,7 +1293,8 @@ static int tls_device_down(struct net_device *netdev) if (ctx->tx_conf == TLS_HW) netdev->tlsdev_ops->tls_dev_del(netdev, ctx, TLS_OFFLOAD_CTX_DIR_TX); - if (ctx->rx_conf == TLS_HW) + if (ctx->rx_conf == TLS_HW && + !test_bit(TLS_RX_DEV_CLOSED, &ctx->flags)) netdev->tlsdev_ops->tls_dev_del(netdev, ctx, TLS_OFFLOAD_CTX_DIR_RX); WRITE_ONCE(ctx->netdev, NULL);