diff options
Diffstat (limited to 'security')
| -rw-r--r-- | security/Kconfig.hardening | 57 |
1 files changed, 57 insertions, 0 deletions
diff --git a/security/Kconfig.hardening b/security/Kconfig.hardening index 19881341f1c2..a96d4a43ca65 100644 --- a/security/Kconfig.hardening +++ b/security/Kconfig.hardening @@ -88,6 +88,63 @@ config GCC_PLUGIN_STRUCTLEAK_VERBOSE initialized. Since not all existing initializers are detected by the plugin, this can produce false positive warnings. +config GCC_PLUGIN_STACKLEAK + bool "Poison kernel stack before returning from syscalls" + depends on GCC_PLUGINS + depends on HAVE_ARCH_STACKLEAK + help + This option makes the kernel erase the kernel stack before + returning from system calls. This has the effect of leaving + the stack initialized to the poison value, which both reduces + the lifetime of any sensitive stack contents and reduces + potential for uninitialized stack variable exploits or information + exposures (it does not cover functions reaching the same stack + depth as prior functions during the same syscall). This blocks + most uninitialized stack variable attacks, with the performance + impact being driven by the depth of the stack usage, rather than + the function calling complexity. + + The performance impact on a single CPU system kernel compilation + sees a 1% slowdown, other systems and workloads may vary and you + are advised to test this feature on your expected workload before + deploying it. + + This plugin was ported from grsecurity/PaX. More information at: + * 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. + +config STACKLEAK_METRICS + bool "Show STACKLEAK metrics in the /proc file system" + depends on GCC_PLUGIN_STACKLEAK + depends on PROC_FS + help + If this is set, STACKLEAK metrics for every task are available in + the /proc file system. In particular, /proc/<pid>/stack_depth + shows the maximum kernel stack consumption for the current and + previous syscalls. Although this information is not precise, it + can be useful for estimating the STACKLEAK performance impact for + your workloads. + +config STACKLEAK_RUNTIME_DISABLE + bool "Allow runtime disabling of kernel stack erasing" + depends on GCC_PLUGIN_STACKLEAK + help + This option provides 'stack_erasing' sysctl, which can be used in + runtime to control kernel stack erasing for kernels built with + CONFIG_GCC_PLUGIN_STACKLEAK. + endmenu endmenu |