linux/security
Kees Cook 22ec1a2aea /dev/mem: Add bounce buffer for copy-out
As done for /proc/kcore in

  commit df04abfd18 ("fs/proc/kcore.c: Add bounce buffer for ktext data")

this adds a bounce buffer when reading memory via /dev/mem. This
is needed to allow kernel text memory to be read out when built with
CONFIG_HARDENED_USERCOPY (which refuses to read out kernel text) and
without CONFIG_STRICT_DEVMEM (which would have refused to read any RAM
contents at all).

Since this build configuration isn't common (most systems with
CONFIG_HARDENED_USERCOPY also have CONFIG_STRICT_DEVMEM), this also tries
to inform Kconfig about the recommended settings.

This patch is modified from Brad Spengler/PaX Team's changes to /dev/mem
code in the last public patch of grsecurity/PaX based on my understanding
of the code. Changes or omissions from the original code are mine and
don't reflect the original grsecurity/PaX code.

Reported-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Fixes: f5509cc18d ("mm: Hardened usercopy")
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-18 15:59:17 +01:00
..
apparmor bug fixes: 2017-11-30 18:56:41 -05:00
integrity ima: do not update security.ima if appraisal status is not INTEGRITY_PASS 2017-11-20 08:23:10 +11:00
keys KEYS: reject NULL restriction string when type is specified 2017-12-08 15:13:29 +00:00
loadpin security: mark LSM hooks as __ro_after_init 2017-03-06 11:00:15 +11:00
selinux selinux/stable-4.15 PR 20171113 2017-11-15 13:32:56 -08:00
smack Merge branch 'next-general' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2017-11-13 10:30:44 -08:00
tomoyo Merge branch 'next-general' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2017-11-13 10:30:44 -08:00
yama doc: ReSTify Yama.txt 2017-05-18 10:33:04 -06:00
commoncap.c Merge branch 'next-general' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2017-11-13 10:30:44 -08:00
device_cgroup.c device_cgroup: prepare code for bpf-based device controller 2017-11-05 23:26:51 +09:00
inode.c securityfs: add the ability to support symlinks 2017-06-08 12:51:43 -07:00
Kconfig /dev/mem: Add bounce buffer for copy-out 2017-12-18 15:59:17 +01:00
lsm_audit.c lsm_audit: update my email address 2017-08-17 15:33:39 -04:00
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
min_addr.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
security.c security: bpf: Add LSM hooks for bpf object related syscall 2017-10-20 13:32:59 +01:00