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Filename Latest commit message Latest commit date
Vinay Kumar Yadav cf4cc95a15 net/tls: fix race condition causing kernel panic
[ Upstream commit 0cada33241d9de205522e3858b18e506ca5cce2c ]

tls_sw_recvmsg() and tls_decrypt_done() can be run concurrently.
// tls_sw_recvmsg()
	if (atomic_read(&ctx->decrypt_pending))
		crypto_wait_req(-EINPROGRESS, &ctx->async_wait);
	else
		reinit_completion(&ctx->async_wait.completion);

//tls_decrypt_done()
  	pending = atomic_dec_return(&ctx->decrypt_pending);

  	if (!pending && READ_ONCE(ctx->async_notify))
  		complete(&ctx->async_wait.completion);

Consider the scenario tls_decrypt_done() is about to run complete()

	if (!pending && READ_ONCE(ctx->async_notify))

and tls_sw_recvmsg() reads decrypt_pending == 0, does reinit_completion(),
then tls_decrypt_done() runs complete(). This sequence of execution
results in wrong completion. Consequently, for next decrypt request,
it will not wait for completion, eventually on connection close, crypto
resources freed, there is no way to handle pending decrypt response.

This race condition can be avoided by having atomic_read() mutually
exclusive with atomic_dec_return(),complete().Intoduced spin lock to
ensure the mutual exclution.

Addressed similar problem in tx direction.

v1->v2:
- More readable commit message.
- Corrected the lock to fix new race scenario.
- Removed barrier which is not needed now.

Fixes: a42055e8d2 ("net/tls: Add support for async encryption of records for performance")
Signed-off-by: Vinay Kumar Yadav <vinay.yadav@chelsio.com>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-03 08:21:01 +02:00
arch x86/unwind/orc: Fix unwind_get_return_address_ptr() for inactive tasks 2020-05-27 17:46:50 +02:00
block
certs
crypto gcc-10: avoid shadowing standard library 'free()' in crypto 2020-05-20 08:20:29 +02:00
Documentation
drivers net: mvpp2: fix RX hashing for non-10G ports 2020-06-03 08:20:55 +02:00
fs rxrpc: Fix the excessive initial retransmission timeout 2020-05-27 17:46:48 +02:00
include net/tls: fix race condition causing kernel panic 2020-06-03 08:21:01 +02:00
init x86: Fix early boot crash on gcc-10, third try 2020-05-20 08:20:34 +02:00
ipc
kernel sched/fair: Fix enqueue_task_fair() warning some more 2020-05-27 17:46:52 +02:00
lib vsprintf: don't obfuscate NULL and error pointers 2020-05-27 17:46:43 +02:00
LICENSES
mm kasan: disable branch tracing for core runtime 2020-05-27 17:46:48 +02:00
net net/tls: fix race condition causing kernel panic 2020-06-03 08:21:01 +02:00
samples
scripts kbuild: Remove debug info from kallsyms linking 2020-05-27 17:46:44 +02:00
security apparmor: Fix aa_label refcnt leak in policy_update 2020-05-27 17:46:42 +02:00
sound ALSA: hda/realtek - Add more fixup entries for Clevo machines 2020-05-27 17:46:40 +02:00
tools KVM: selftests: Fix build for evmcs.h 2020-05-27 17:46:36 +02:00
usr
virt
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.get_maintainer.ignore
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COPYING
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Makefile Linux 5.4.43 2020-05-27 17:46:53 +02:00
README

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.