diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/Kconfig.debug | 18 | ||||
| -rw-r--r-- | lib/Makefile | 1 | ||||
| -rw-r--r-- | lib/usercopy.c | 9 |
3 files changed, 28 insertions, 0 deletions
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 77ebaa3dfa12..770a422a42e8 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1292,6 +1292,24 @@ config LATENCYTOP Enable this option if you want to use the LatencyTOP tool to find out which userspace is blocking on what kernel operations. +config ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS + bool + +config DEBUG_STRICT_USER_COPY_CHECKS + bool "Strict user copy size checks" + depends on ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS + depends on DEBUG_KERNEL && !TRACE_BRANCH_PROFILING + help + Enabling this option turns a certain set of sanity checks for user + copy operations into compile time failures. + + The copy_from_user() etc checks are there to help test if there + are sufficient security checks on the length argument of + the copy operation, by having gcc prove that the argument is + within bounds. + + If unsure, say N. + source mm/Kconfig.debug source kernel/trace/Kconfig diff --git a/lib/Makefile b/lib/Makefile index 23c9a0fe74fc..e9c52e1b853a 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -15,6 +15,7 @@ lib-y := ctype.o string.o vsprintf.o cmdline.o \ is_single_threaded.o plist.o decompress.o kobject_uevent.o \ earlycpio.o +obj-$(CONFIG_ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS) += usercopy.o lib-$(CONFIG_MMU) += ioremap.o lib-$(CONFIG_SMP) += cpumask.o diff --git a/lib/usercopy.c b/lib/usercopy.c new file mode 100644 index 000000000000..4f5b1ddbcd25 --- /dev/null +++ b/lib/usercopy.c @@ -0,0 +1,9 @@ +#include <linux/export.h> +#include <linux/bug.h> +#include <linux/uaccess.h> + +void copy_from_user_overflow(void) +{ + WARN(1, "Buffer overflow detected!\n"); +} +EXPORT_SYMBOL(copy_from_user_overflow); |