evie/android_kernel_oneplus_msm8998
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

UPSTREAM: Make the hardened user-copy code depend on having a hardened allocator

Browse source 
The kernel test robot reported a usercopy failure in the new hardened
sanity checks, due to a page-crossing copy of the FPU state into the
task structure.

This happened because the kernel test robot was testing with SLOB, which
doesn't actually do the required book-keeping for slab allocations, and
as a result the hardening code didn't realize that the task struct
allocation was one single allocation - and the sanity checks fail.

Since SLOB doesn't even claim to support hardening (and you really
shouldn't use it), the straightforward solution is to just make the
usercopy hardening code depend on the allocator supporting it.

Reported-by: kernel test robot <xiaolong.ye@intel.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Change-Id: I37d51f866f873341bf7d5297249899b852e1c6ce
(cherry picked from commit 6040e57658eee6eb1315a26119101ca832d1f854)
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
This commit is contained in:
Linus Torvalds 2016-08-19 12:47:01 -07:00 • committed by Amit Pundir
parent 8e4b2f84a8
commit 03eb77747d
1 changed files with 1 additions and 0 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

1
security/Kconfig
View file

@ -145,6 +145,7 @@ config HAVE_ARCH_HARDENED_USERCOPY
config HARDENED_USERCOPY
bool "Harden memory copies between kernel and userspace"
depends on HAVE_ARCH_HARDENED_USERCOPY
depends on HAVE_HARDENED_USERCOPY_ALLOCATOR
select BUG
help
This option checks for obviously wrong memory regions when