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Filename Latest commit message Latest commit date
Ondrej Mosnacek 66a2a494ac serial: core: fix suspicious security_locked_down() call
commit 5e722b217ad3cf41f5504db80a68062df82b5242 upstream.

The commit that added this check did so in a very strange way - first
security_locked_down() is called, its value stored into retval, and if
it's nonzero, then an additional check is made for (change_irq ||
change_port), and if this is true, the function returns. However, if
the goto exit branch is not taken, the code keeps the retval value and
continues executing the function. Then, depending on whether
uport->ops->verify_port is set, the retval value may or may not be reset
to zero and eventually the error value from security_locked_down() may
abort the function a few lines below.

I will go out on a limb and assume that this isn't the intended behavior
and that an error value from security_locked_down() was supposed to
abort the function only in case (change_irq || change_port) is true.

Note that security_locked_down() should be called last in any series of
checks, since the SELinux implementation of this hook will do a check
against the policy and generate an audit record in case of denial. If
the operation was to carry on after calling security_locked_down(), then
the SELinux denial record would be bogus.

See commit 59438b46471a ("security,lockdown,selinux: implement SELinux
lockdown") for how SELinux implements this hook.

Fixes: 794edf30ee ("lockdown: Lock down TIOCSSERIAL")
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20210507115719.140799-1-omosnace@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-06-03 08:59:03 +02:00
arch openrisc: Fix a memory leak 2021-05-26 12:05:14 +02:00
block blk-mq: Swap two calls in blk_mq_exit_queue() 2021-05-19 10:08:30 +02:00
certs certs: Fix blacklist flag type confusion 2021-03-04 10:26:29 +01:00
crypto crypto: rng - fix crypto_rng_reset() refcounting when !CRYPTO_STATS 2021-05-11 14:04:15 +02:00
Documentation Documentation: seccomp: Fix user notification documentation 2021-06-03 08:59:03 +02:00
drivers serial: core: fix suspicious security_locked_down() call 2021-06-03 08:59:03 +02:00
fs proc: Check /proc/$pid/attr/ writes against file opener 2021-06-03 08:59:01 +02:00
include mac80211: properly handle A-MSDUs that start with an RFC 1042 header 2021-06-03 08:59:01 +02:00
init init/Kconfig: make COMPILE_TEST depend on HAS_IOMEM 2021-04-10 13:34:32 +02:00
ipc
kernel bpf: No need to simulate speculative domain for immediates 2021-05-28 13:10:26 +02:00
lib lib: stackdepot: turn depot_lock spinlock to raw_spinlock 2021-05-22 11:38:30 +02:00
LICENSES
mm mm/hugetlb: fix F_SEAL_FUTURE_WRITE 2021-05-19 10:08:29 +02:00
net mac80211: extend protection against mixed key and fragment cache attacks 2021-06-03 08:59:02 +02:00
samples samples/bpf: Fix broken tracex1 due to kprobe argument change 2021-05-19 10:08:23 +02:00
scripts scripts: switch explicitly to Python 3 2021-05-22 11:38:30 +02:00
security security: commoncap: fix -Wstringop-overread warning 2021-05-11 14:04:16 +02:00
sound ALSA: usb-audio: scarlett2: Improve driver startup messages 2021-06-03 08:59:00 +02:00
tools selftests/gpio: Fix build when source tree is read only 2021-06-03 08:59:03 +02:00
usr
virt KVM: arm64: Initialize VCPU mdcr_el2 before loading it 2021-05-22 11:38:30 +02:00
.clang-format
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore
.mailmap
COPYING
CREDITS
Kbuild
Kconfig
MAINTAINERS
Makefile Linux 5.4.123 2021-05-28 13:10:27 +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.