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Jacob Keller 2df4de1681 ptp: correctly disable flags on old ioctls
Commit 415606588c ("PTP: introduce new versions of IOCTLs",
2019-09-13) introduced new versions of the PTP ioctls which actually
validate that the flags are acceptable values.

As part of this, it cleared the flags value using a bitwise
and+negation, in an attempt to prevent the old ioctl from accidentally
enabling new features.

This is incorrect for a couple of reasons. First, it results in
accidentally preventing previously working flags on the request ioctl.
By clearing the "valid" flags, we now no longer allow setting the
enable, rising edge, or falling edge flags.

Second, if we add new additional flags in the future, they must not be
set by the old ioctl. (Since the flag wasn't checked before, we could
potentially break userspace programs which sent garbage flag data.

The correct way to resolve this is to check for and clear all but the
originally valid flags.

Create defines indicating which flags are correctly checked and
interpreted by the original ioctls. Use these to clear any bits which
will not be correctly interpreted by the original ioctls.

In the future, new flags must be added to the VALID_FLAGS macros, but
*not* to the V1_VALID_FLAGS macros. In this way, new features may be
exposed over the v2 ioctls, but without breaking previous userspace
which happened to not clear the flags value properly. The old ioctl will
continue to behave the same way, while the new ioctl gains the benefit
of using the flags fields.

Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Felipe Balbi <felipe.balbi@linux.intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Christopher Hall <christopher.s.hall@intel.com>
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-09-27 20:25:32 +02:00
arch Merge branch 'work.namei' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-09-18 13:03:01 -07:00
block for-5.4/block-2019-09-16 2019-09-17 16:57:47 -07:00
certs Revert "Merge tag 'keys-acl-20190703' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs" 2019-07-10 18:43:43 -07:00
crypto padata, pcrypt: take CPU hotplug lock internally in padata_alloc_possible 2019-09-13 21:15:40 +10:00
Documentation dt-bindings: net: ravb: Add support for r8a774b1 SoC 2019-09-26 09:30:13 +02:00
drivers ptp: correctly disable flags on old ioctls 2019-09-27 20:25:32 +02:00
fs New code for 5.4: 2019-09-18 18:32:43 -07:00
include ptp: correctly disable flags on old ioctls 2019-09-27 20:25:32 +02:00
init Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-09-17 12:35:15 -07:00
ipc Merge branch 'work.mount-base' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-09-18 13:15:58 -07:00
kernel bpf: Fix bpf_event_output re-entry issue 2019-09-27 11:24:29 +02:00
lib lib: dimlib: fix help text typos 2019-09-27 20:23:37 +02:00
LICENSES LICENSES: Rename other to deprecated 2019-05-03 06:34:32 -06:00
mm New code for 5.4: 2019-09-18 18:32:43 -07:00
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf 2019-09-27 20:15:00 +02:00
samples samples/bpf: fix xdpsock l2fwd tx for unaligned mode 2019-09-16 09:35:10 +02:00
scripts Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next 2019-09-18 12:34:53 -07:00
security keys: Fix missing null pointer check in request_key_auth_describe() 2019-09-05 14:19:25 -07:00
sound LED updates for 5.4-rc1 2019-09-17 18:40:42 -07:00
tools Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf 2019-09-27 16:23:32 +02:00
usr netfilter: ebtables: use __u8 instead of uint8_t in uapi header 2019-09-25 11:00:46 +02:00
virt * s390: ioctl hardening, selftests 2019-09-18 09:49:13 -07:00
.clang-format clang-format: Update with the latest for_each macro list 2019-08-31 10:00:51 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore .gitignore: Add compilation database file 2019-07-27 12:18:19 +09:00
.mailmap Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next 2019-09-18 12:34:53 -07:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS CREDITS: Update email address 2019-09-13 17:21:38 +03:00
Kbuild Kbuild updates for v5.1 2019-03-10 17:48:21 -07:00
Kconfig docs: kbuild: convert docs to ReST and rename to *.rst 2019-06-14 14:21:21 -06:00
MAINTAINERS MAINTAINERS: add Yanjun to FORCEDETH maintainers list 2019-09-26 08:51:21 +02:00
Makefile arm64 updates for 5.4: 2019-09-16 14:31:40 -07:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

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.