On Thu, Mar 23, 2017 at 1:15 PM, Kees Cook <keescook@xxxxxxxxxxxx> wrote: > On Thu, Mar 23, 2017 at 10:25 AM, Thomas Garnier <thgarnie@xxxxxxxxxx> wrote: >> This patch ensures a syscall does not return to user-mode with a kernel >> address limit. If that happened, a process can corrupt kernel-mode >> memory and elevate privileges. >> >> For example, it would mitigation this bug: >> >> - https://bugs.chromium.org/p/project-zero/issues/detail?id=990 >> >> The CONFIG_ARCH_NO_SYSCALL_VERIFY_PRE_USERMODE_STATE option is also >> added so each architecture can optimize this change. >> >> Signed-off-by: Thomas Garnier <thgarnie@xxxxxxxxxx> > > Awesome. :) I've tested this on x86 and arm with the LKDTM patch I'll > post in a moment. > > [ 46.977823] lkdtm: Performing direct entry CORRUPT_USER_DS > [ 46.978966] lkdtm: setting bad task size limit > [ 46.980302] ------------[ cut here ]------------ > [ 46.981219] kernel BUG at ./include/linux/syscalls.h:200! > > Tested-by: Kees Cook <keescook@xxxxxxxxxxxx> Thanks Kees. Any additional feedback? Andy? > > (Also note, your Signed-off-by lines are missing in patches 2-4) > > -- > Kees Cook > Pixel Security -- Thomas -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
