commit 7a7003b1da010d2b0d1dc8bf21c10f5c73b389f1
author Mark Rutland <mark.rutland@arm.com> Thu Nov 02 16:12:03 2017 +0000
committer Catalin Marinas <catalin.marinas@arm.com> Thu Nov 02 18:33:08 2017 +0000
tree 8a89f339577c823f3b0e37d0380cdbc792046150
parent 0b07194bb55ed836c2cc7c22e866b87a14681984

arm64: ensure __dump_instr() checks addr_limit

It's possible for a user to deliberately trigger __dump_instr with a
chosen kernel address.

Let's avoid problems resulting from this by using get_user() rather than
__get_user(), ensuring that we don't erroneously access kernel memory.

Where we use __dump_instr() on kernel text, we already switch to
KERNEL_DS, so this shouldn't adversely affect those cases.

Fixes: 60ffc30d5652810d ("arm64: Exception handling")
Cc: stable@vger.kernel.org
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>