Maxim Mikityanskiy c55dcdd435 net/tls: Fix use-after-free after the TLS device goes down and up ... When a netdev with active TLS offload goes down, tls_device_down is called to stop the offload and tear down the TLS context. However, the socket stays alive, and it still points to the TLS context, which is now deallocated. If a netdev goes up, while the connection is still active, and the data flow resumes after a number of TCP retransmissions, it will lead to a use-after-free of the TLS context. This commit addresses this bug by keeping the context alive until its normal destruction, and implements the necessary fallbacks, so that the connection can resume in software (non-offloaded) kTLS mode. On the TX side tls_sw_fallback is used to encrypt all packets. The RX side already has all the necessary fallbacks, because receiving non-decrypted packets is supported. The thing needed on the RX side is to block resync requests, which are normally produced after receiving non-decrypted packets. The necessary synchronization is implemented for a graceful teardown: first the fallbacks are deployed, then the driver resources are released (it used to be possible to have a tls_dev_resync after tls_dev_del). A new flag called TLS_RX_DEV_DEGRADED is added to indicate the fallback mode. It's used to skip the RX resync logic completely, as it becomes useless, and some objects may be released (for example, resync_async, which is allocated and freed by the driver). Fixes: e8f6979981 ("net/tls: Add generic NIC offload infrastructure") Signed-off-by: Maxim Mikityanskiy <maximmi@nvidia.com> Reviewed-by: Tariq Toukan <tariqt@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>		2021-06-01 15:58:05 -07:00
..
Kconfig	net/tls: Select SOCK_RX_QUEUE_MAPPING from TLS_DEVICE	2021-02-11 19:08:06 -08:00
Makefile	net/tls: add skeleton of MIB statistics	2019-10-05 16:29:00 -07:00
tls_device_fallback.c	net/tls: Fix use-after-free after the TLS device goes down and up	2021-06-01 15:58:05 -07:00
tls_device.c	net/tls: Fix use-after-free after the TLS device goes down and up	2021-06-01 15:58:05 -07:00
tls_main.c	net/tls: Fix use-after-free after the TLS device goes down and up	2021-06-01 15:58:05 -07:00
tls_proc.c	net: fix proc_fs init handling in af_packet and tls	2020-12-14 19:39:30 -08:00
tls_sw.c	tls splice: check SPLICE_F_NONBLOCK instead of MSG_DONTWAIT	2021-05-14 15:03:25 -07:00
tls_toe.c	net/tls: rename tls_hw_* functions tls_toe_*	2019-10-04 14:07:07 -07:00
trace.c	net/tls: add tracing for device/offload events	2019-10-05 16:29:00 -07:00
trace.h	net/tls: add device decrypted trace point	2019-10-05 16:29:00 -07:00