Messages in this thread | | | From | Eddie Kovsky <> | Subject | [PATCH v5 0/2] provide check for ro_after_init memory sections | Date | Wed, 5 Apr 2017 21:35:48 -0600 |
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Provide a mechanism for other functions to verify that their arguments are read-only.
This implements the first half of a suggestion made by Kees Cook for the Kernel Self Protection Project:
- provide mechanism to check for ro_after_init memory areas, and reject structures not marked ro_after_init in vmbus_register()
http://www.openwall.com/lists/kernel-hardening/2017/02/04/1
The idea is to prevent structures (including modules) that are not read-only from being passed to functions. It builds upon the functions in kernel/extable.c that test if an address is in the text section.
A build failure on the Blackfin architecture led to the discovery of an incomplete definition of the RO_DATA macro used in this series. The fixes are in linux-next:
commit 906f2a51c941 ("mm: fix section name for .data..ro_after_init")
commit 939897e2d736 ("vmlinux.lds: add missing VMLINUX_SYMBOL macros")
The latest version of this series uses new symbols provided in these fixes. The series now cross compiles on Blackfin without errors. I have also test compiled this series on next-20170405 for x86.
I have dropped the third patch that uses these features to check the arguments to vmbus_register() because the maintainers have not been receptive to using it. My goal right now is to get the API right.
Eddie Kovsky (2): module: verify address is read-only extable: verify address is read-only
include/linux/kernel.h | 2 ++ include/linux/module.h | 12 ++++++++++++ kernel/extable.c | 29 +++++++++++++++++++++++++++ kernel/module.c | 53 ++++++++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 96 insertions(+)
-- 2.12.2
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