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authorAlexander Popov <alex.popov@linux.com>2018-08-17 01:16:59 +0300
committerKees Cook <keescook@chromium.org>2018-09-04 10:35:47 -0700
commit10e9ae9fabaf96c8e5227c1cd4827d58b3aa406d (patch)
tree910b011e7c95ba67dba361b876f79328151f202f /scripts/gcc-plugins/Kconfig
parentx86/entry: Add STACKLEAK erasing the kernel stack at the end of syscalls (diff)
downloadlinux-dev-10e9ae9fabaf96c8e5227c1cd4827d58b3aa406d.tar.xz
linux-dev-10e9ae9fabaf96c8e5227c1cd4827d58b3aa406d.zip
gcc-plugins: Add STACKLEAK plugin for tracking the kernel stack
The STACKLEAK feature erases the kernel stack before returning from syscalls. That reduces the information which kernel stack leak bugs can reveal and blocks some uninitialized stack variable attacks. This commit introduces the STACKLEAK gcc plugin. It is needed for tracking the lowest border of the kernel stack, which is important for the code erasing the used part of the kernel stack at the end of syscalls (comes in a separate commit). The STACKLEAK feature is ported from grsecurity/PaX. More information at: https://grsecurity.net/ https://pax.grsecurity.net/ This code is modified from Brad Spengler/PaX Team's code in the last public patch of grsecurity/PaX based on our understanding of the code. Changes or omissions from the original code are ours and don't reflect the original grsecurity/PaX code. Signed-off-by: Alexander Popov <alex.popov@linux.com> Tested-by: Laura Abbott <labbott@redhat.com> Signed-off-by: Kees Cook <keescook@chromium.org>
Diffstat (limited to 'scripts/gcc-plugins/Kconfig')
-rw-r--r--scripts/gcc-plugins/Kconfig12
1 files changed, 12 insertions, 0 deletions
diff --git a/scripts/gcc-plugins/Kconfig b/scripts/gcc-plugins/Kconfig
index 977b84e69787..c65fdd823591 100644
--- a/scripts/gcc-plugins/Kconfig
+++ b/scripts/gcc-plugins/Kconfig
@@ -158,4 +158,16 @@ config GCC_PLUGIN_STACKLEAK
* https://grsecurity.net/
* https://pax.grsecurity.net/
+config STACKLEAK_TRACK_MIN_SIZE
+ int "Minimum stack frame size of functions tracked by STACKLEAK"
+ default 100
+ range 0 4096
+ depends on GCC_PLUGIN_STACKLEAK
+ help
+ The STACKLEAK gcc plugin instruments the kernel code for tracking
+ the lowest border of the kernel stack (and for some other purposes).
+ It inserts the stackleak_track_stack() call for the functions with
+ a stack frame size greater than or equal to this parameter.
+ If unsure, leave the default value 100.
+
endif