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Aneesh Kumar K.V 19ab500edb powerpc/mm/pkeys: Make pkey access check work on execute_only_key 
Jan reported that LTP mmap03 was getting stuck in a page fault loop
after commit c46241a370 ("powerpc/pkeys: Check vma before returning
key fault error to the user"), as well as a minimised reproducer:

  #include <fcntl.h>
  #include <stdio.h>
  #include <stdlib.h>
  #include <unistd.h>
  #include <sys/mman.h>

  int main(int ac, char **av)
  {
  	int page_sz = getpagesize();
  	int fildes;
  	char *addr;

  	fildes = open("tempfile", O_WRONLY | O_CREAT, 0666);
  	write(fildes, &fildes, sizeof(fildes));
  	close(fildes);

  	fildes = open("tempfile", O_RDONLY);
  	unlink("tempfile");

  	addr = mmap(0, page_sz, PROT_EXEC, MAP_FILE | MAP_PRIVATE, fildes, 0);

  	printf("%d\n", *addr);
  	return 0;
  }

And noticed that access_pkey_error() in page fault handler now always
seem to return false:

  __do_page_fault
    access_pkey_error(is_pkey: 1, is_exec: 0, is_write: 0)
      arch_vma_access_permitted
	pkey_access_permitted
	  if (!is_pkey_enabled(pkey))
	    return true
      return false

pkey_access_permitted() should not check if the pkey is available in
UAMOR (using is_pkey_enabled()). The kernel needs to do that check
only when allocating keys. This also makes sure the execute_only_key
which is marked as non-manageable via UAMOR is handled correctly in
pkey_access_permitted(), and fixes the bug.

Fixes: c46241a370 ("powerpc/pkeys: Check vma before returning key fault error to the user")
Reported-by: Jan Stancek <jstancek@redhat.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
[mpe: Include bug report details etc. in the change log]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200627070147.297535-1-aneesh.kumar@linux.ibm.com
2020-06-29 16:17:02 +10:00
arch powerpc/mm/pkeys: Make pkey access check work on execute_only_key 2020-06-29 16:17:02 +10:00
block block-5.8-2020-06-19 2020-06-19 13:11:26 -07:00
certs .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
crypto crypto: drbg - always try to free Jitter RNG instance 2020-06-15 17:38:54 +10:00
Documentation Merge branch 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux 2020-06-20 19:18:27 -07:00
drivers Pin control fixes for the v5.8 cycle, first take: 2020-06-21 13:04:57 -07:00
fs A few fixes and small cleanups for tracing: 2020-06-20 13:17:47 -07:00
include powerpc fixes for 5.8 #3 2020-06-21 10:02:53 -07:00
init Kbuild updates for v5.8 (2nd) 2020-06-13 13:29:16 -07:00
ipc mmap locking API: use coccinelle to convert mmap_sem rwsem call sites 2020-06-09 09:39:14 -07:00
kernel A few fixes and small cleanups for tracing: 2020-06-20 13:17:47 -07:00
lib Kbuild fixes for v5.8 2020-06-21 12:44:52 -07:00
LICENSES LICENSES: Rename other to deprecated 2019-05-03 06:34:32 -06:00
mm powerpc fixes for 5.8 #3 2020-06-21 10:02:53 -07:00
net An important follow-up for replica reads support that went into -rc1 2020-06-19 12:25:04 -07:00
samples Kbuild fixes for v5.8 2020-06-21 12:44:52 -07:00
scripts Kbuild fixes for v5.8 2020-06-21 12:44:52 -07:00
security selinux/stable-5.8 PR 20200621 2020-06-21 15:41:24 -07:00
sound ASoC: SOF: Replace zero-length array with flexible-array 2020-06-15 23:08:32 -05:00
tools selftests/powerpc: Fix build failure in ebb tests 2020-06-26 12:53:09 +10:00
usr bpfilter: match bit size of bpfilter_umh to that of the kernel 2020-05-17 18:52:01 +09:00
virt MIPS: 2020-06-12 11:05:52 -07:00
.clang-format block: add bio_for_each_bvec_all() 2020-05-25 11:25:24 +02:00
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore modpost: generate vmlinux.symvers and reuse it for the second modpost 2020-06-06 23:38:12 +09:00
.mailmap A fair amount of stuff this time around, dominated by yet another massive 2020-06-01 15:45:27 -07:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS mailmap: change email for Ricardo Ribalda 2020-05-25 18:59:59 -06:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS Merge branch 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux 2020-06-20 19:18:27 -07:00
Makefile Linux 5.8-rc2 2020-06-21 15:45:29 -07:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

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.