linux/include
Jann Horn 9da3f2b740 x86/fault: BUG() when uaccess helpers fault on kernel addresses
There have been multiple kernel vulnerabilities that permitted userspace to
pass completely unchecked pointers through to userspace accessors:

 - the waitid() bug - commit 96ca579a1e ("waitid(): Add missing
   access_ok() checks")
 - the sg/bsg read/write APIs
 - the infiniband read/write APIs

These don't happen all that often, but when they do happen, it is hard to
test for them properly; and it is probably also hard to discover them with
fuzzing. Even when an unmapped kernel address is supplied to such buggy
code, it just returns -EFAULT instead of doing a proper BUG() or at least
WARN().

Try to make such misbehaving code a bit more visible by refusing to do a
fixup in the pagefault handler code when a userspace accessor causes a #PF
on a kernel address and the current context isn't whitelisted.

Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Kees Cook <keescook@chromium.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: kernel-hardening@lists.openwall.com
Cc: dvyukov@google.com
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Cc: Borislav Petkov <bp@alien8.de>
Link: https://lkml.kernel.org/r/20180828201421.157735-7-jannh@google.com
2018-09-03 15:12:09 +02:00
..
acpi ACPICA: Update version to 20180810 2018-08-14 23:49:13 +02:00
asm-generic Kbuild updates for v4.19 (2nd) 2018-08-25 13:40:38 -07:00
clocksource
crypto crypto: scatterwalk - remove scatterwalk_samebuf() 2018-08-03 18:06:04 +08:00
drm drm pull for 4.19-rc1 2018-08-15 17:39:07 -07:00
dt-bindings ARM: SoC: late updates 2018-08-25 14:12:36 -07:00
keys
kvm KVM: arm/arm64: vgic-v3: Add core support for Group0 SGIs 2018-08-12 12:06:34 +01:00
linux x86/fault: BUG() when uaccess helpers fault on kernel addresses 2018-09-03 15:12:09 +02:00
math-emu
media - New Drivers 2018-08-20 15:38:44 -07:00
memory
misc
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-08-27 11:59:39 -07:00
pcmcia pcmcia: remove long deprecated pcmcia_request_exclusive_irq() function 2018-08-18 12:30:42 -07:00
ras
rdma Second merge window update 2018-08-23 15:34:48 -07:00
scsi SCSI misc on 20180815 2018-08-15 22:06:26 -07:00
soc
sound ASoC: Updates for v4.19 2018-08-13 12:12:31 +02:00
target scsi: target: add session removal function 2018-08-02 15:29:31 -04:00
trace Merge branch 'for-4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup 2018-08-24 13:19:27 -07:00
uapi This pull request contains updates for both UBI and UBIFS: 2018-08-23 15:58:04 -07:00
video fbdev changes for v4.19: 2018-08-23 15:44:58 -07:00
xen Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input 2018-08-18 16:48:07 -07:00