linux/include
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
..
acpi
asm-generic mm: remove xlate_dev_kmem_ptr() 2021-05-07 00:26:34 -07:00
clocksource ARM: platform support for Apple M1 2021-04-26 12:30:36 -07:00
crypto
drm
dt-bindings Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input 2021-05-06 23:37:55 -07:00
keys integrity-v5.13 2021-05-01 15:32:18 -07:00
kunit
kvm
linux Networking fixes for 5.13-rc4, including fixes from bpf, netfilter, 2021-05-26 17:44:49 -10:00
math-emu
media media updates for v5.13-rc1 2021-04-28 09:24:36 -07:00
memory
misc
net net/tls: Fix use-after-free after the TLS device goes down and up 2021-06-01 15:58:05 -07:00
pcmcia
ras
rdma
scsi SCSI misc on 20210428 2021-04-28 17:22:10 -07:00
soc Networking changes for 5.13. 2021-04-29 11:57:23 -07:00
sound
target
trace NFS client updates for Linux 5.13 2021-05-07 11:23:41 -07:00
uapi Merge branch 'for-v5.13-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2021-05-21 06:12:52 -10:00
vdso
video
xen xen/arm: move xen_swiotlb_detect to arm/swiotlb-xen.h 2021-05-14 15:52:05 +02:00