On Wed, Sep 14, 2016 at 04:47:47PM +0100, Al Viro wrote: > Fixes for broken uaccess primitives - mostly lack of proper zeroing > in copy_from_user()/get_user()/__get_user(), but for several architectures > there's more (broken clear_user() on frv and strncpy_from_user() on hexagon). > All of that is rc2-based stable fodder; usercopy stuff that went into mainline > since then has added 3 conflicts - in parisc, ppc and itanic uaccess.h. > Conflicts are trivial; I've pushed my variant of conflict resolution into > #proposed-merge.
And a bit that has sat in a different branch since mid-August: [x86] fix minor infoleak in get_user_ex() get_user_ex(x, ptr) should zero x on failure. It's not a lot of a leak (at most we are leaking uninitialized 64bit value off the kernel stack, and in a fairly constrained situation, at that), but the fix is trivial, so... Cc: [email protected] Signed-off-by: Al Viro <[email protected]> --- diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h index a0ae610..7821921 100644 --- a/arch/x86/include/asm/uaccess.h +++ b/arch/x86/include/asm/uaccess.h @@ -433,7 +433,11 @@ do { \ #define __get_user_asm_ex(x, addr, itype, rtype, ltype) \ asm volatile("1: mov"itype" %1,%"rtype"0\n" \ "2:\n" \ - _ASM_EXTABLE_EX(1b, 2b) \ + ".section .fixup,\"ax\"\n" \ + "3:xor"itype" %"rtype"0,%"rtype"0\n" \ + " jmp 2b\n" \ + ".previous\n" \ + _ASM_EXTABLE_EX(1b, 3b) \ : ltype(x) : "m" (__m(addr))) #define __put_user_nocheck(x, ptr, size) \
