security/Kconfig: further restrict HARDENED_USERCOPY
PATCH v3 1/1 security/Kconfig: further restrict HARDENED_USERCOPY
It doesn't make sense to have HARDENED_USERCOPY when either /dev/kmem is enabled or /dev/mem can be used to read kernel memory (i.e. !STRICT_DEVMEM).
v2: add !MMU depend as well
v3: drop !MMU, s/ARCH_HAS_DEVMEM_IS_ALLOWED/DEVMEM, which makes the above
commit message actually match the logic again
Signed-off-by Tycho Andersen <[email protected]>
CC Kees Cook <[email protected]>
CC "Serge E. Hallyn" <[email protected]>
CC James Morris <[email protected]>
--- security/Kconfig | 2 ++ 1 file changed, 2 insertions(+)
security/Kconfig +2 -0
@@ -142,6 +142,8 @@ config HARDENED_USERCOPY bool "Harden memory copies between kernel and userspace" depends on HAVE_ARCH_HARDENED_USERCOPY depends on HAVE_HARDENED_USERCOPY_ALLOCATOR + depends on !DEVKMEM + depends on !DEVMEM || STRICT_DEVMEM select BUG help This option checks for obviously wrong memory regions when
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Quoted 4 lines · Tycho Andersen
It doesn't make sense to have
HARDENED_USERCOPYwhen either/dev/kmemis enabled or/dev/memcan be used to read kernel memory (i.e. !STRICT_DEVMEM).
Quoted 8 lines
v2: add !MMU depend as well
v3: drop !MMU, s/ARCH_HAS_DEVMEM_IS_ALLOWED/DEVMEM, which makes the above
commit message actually match the logic againSigned-off-by Tycho Andersen <[email protected]>CC Kees Cook <[email protected]>CC "Serge E. Hallyn" <[email protected]>CC James Morris <[email protected]>
Awesome, thanks! I'll add this to the usercopy tree.
-Kees
Quoted 20 lines
--- security/Kconfig | 2 ++ 1 file changed, 2 insertions(+)security/Kconfig +2
-1@@ -142,6 +142,8 @@ config HARDENED_USERCOPY bool "Harden memory copies between kernel and userspace" depends on HAVE_ARCH_HARDENED_USERCOPY depends on HAVE_HARDENED_USERCOPY_ALLOCATOR + depends on !DEVKMEM + depends on !DEVMEM || STRICT_DEVMEM select BUG help This option checks for obviously wrong memory regions when --2.7.4
Signature · 6 lines
Kees Cook Pixel Security -- To unsubscribe from this list: send the line "unsubscribe linux-security-module" in the body of a message to majordomo at vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html