x86/extable: Introduce _ASM_EXTABLE_UA for uaccess fixups

Currently, most fixups for attempting to access userspace memory are
handled using _ASM_EXTABLE, which is also used for various other types of
fixups (e.g. safe MSR access, IRET failures, and a bunch of other things).
In order to make it possible to add special safety checks to uaccess fixups
(in particular, checking whether the fault address is actually in
userspace), introduce a new exception table handler ex_handler_uaccess()
and wire it up to all the user access fixups (excluding ones that
already use _ASM_EXTABLE_EX).

Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Kees Cook <keescook@chromium.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: kernel-hardening@lists.openwall.com
Cc: dvyukov@google.com
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Cc: Borislav Petkov <bp@alien8.de>
Link: https://lkml.kernel.org/r/20180828201421.157735-5-jannh@google.com
This commit is contained in:
Jann Horn
2018-08-28 22:14:18 +02:00
committed by Thomas Gleixner
parent e3e4d5019c
commit 75045f77f7
12 changed files with 160 additions and 142 deletions

View File

@@ -47,8 +47,8 @@ do { \
"3: lea 0(%2,%0,4),%0\n" \
" jmp 2b\n" \
".previous\n" \
_ASM_EXTABLE(0b,3b) \
_ASM_EXTABLE(1b,2b) \
_ASM_EXTABLE_UA(0b, 3b) \
_ASM_EXTABLE_UA(1b, 2b) \
: "=&c"(size), "=&D" (__d0) \
: "r"(size & 3), "0"(size / 4), "1"(addr), "a"(0)); \
} while (0)
@@ -153,44 +153,44 @@ __copy_user_intel(void __user *to, const void *from, unsigned long size)
"101: lea 0(%%eax,%0,4),%0\n"
" jmp 100b\n"
".previous\n"
_ASM_EXTABLE(1b,100b)
_ASM_EXTABLE(2b,100b)
_ASM_EXTABLE(3b,100b)
_ASM_EXTABLE(4b,100b)
_ASM_EXTABLE(5b,100b)
_ASM_EXTABLE(6b,100b)
_ASM_EXTABLE(7b,100b)
_ASM_EXTABLE(8b,100b)
_ASM_EXTABLE(9b,100b)
_ASM_EXTABLE(10b,100b)
_ASM_EXTABLE(11b,100b)
_ASM_EXTABLE(12b,100b)
_ASM_EXTABLE(13b,100b)
_ASM_EXTABLE(14b,100b)
_ASM_EXTABLE(15b,100b)
_ASM_EXTABLE(16b,100b)
_ASM_EXTABLE(17b,100b)
_ASM_EXTABLE(18b,100b)
_ASM_EXTABLE(19b,100b)
_ASM_EXTABLE(20b,100b)
_ASM_EXTABLE(21b,100b)
_ASM_EXTABLE(22b,100b)
_ASM_EXTABLE(23b,100b)
_ASM_EXTABLE(24b,100b)
_ASM_EXTABLE(25b,100b)
_ASM_EXTABLE(26b,100b)
_ASM_EXTABLE(27b,100b)
_ASM_EXTABLE(28b,100b)
_ASM_EXTABLE(29b,100b)
_ASM_EXTABLE(30b,100b)
_ASM_EXTABLE(31b,100b)
_ASM_EXTABLE(32b,100b)
_ASM_EXTABLE(33b,100b)
_ASM_EXTABLE(34b,100b)
_ASM_EXTABLE(35b,100b)
_ASM_EXTABLE(36b,100b)
_ASM_EXTABLE(37b,100b)
_ASM_EXTABLE(99b,101b)
_ASM_EXTABLE_UA(1b, 100b)
_ASM_EXTABLE_UA(2b, 100b)
_ASM_EXTABLE_UA(3b, 100b)
_ASM_EXTABLE_UA(4b, 100b)
_ASM_EXTABLE_UA(5b, 100b)
_ASM_EXTABLE_UA(6b, 100b)
_ASM_EXTABLE_UA(7b, 100b)
_ASM_EXTABLE_UA(8b, 100b)
_ASM_EXTABLE_UA(9b, 100b)
_ASM_EXTABLE_UA(10b, 100b)
_ASM_EXTABLE_UA(11b, 100b)
_ASM_EXTABLE_UA(12b, 100b)
_ASM_EXTABLE_UA(13b, 100b)
_ASM_EXTABLE_UA(14b, 100b)
_ASM_EXTABLE_UA(15b, 100b)
_ASM_EXTABLE_UA(16b, 100b)
_ASM_EXTABLE_UA(17b, 100b)
_ASM_EXTABLE_UA(18b, 100b)
_ASM_EXTABLE_UA(19b, 100b)
_ASM_EXTABLE_UA(20b, 100b)
_ASM_EXTABLE_UA(21b, 100b)
_ASM_EXTABLE_UA(22b, 100b)
_ASM_EXTABLE_UA(23b, 100b)
_ASM_EXTABLE_UA(24b, 100b)
_ASM_EXTABLE_UA(25b, 100b)
_ASM_EXTABLE_UA(26b, 100b)
_ASM_EXTABLE_UA(27b, 100b)
_ASM_EXTABLE_UA(28b, 100b)
_ASM_EXTABLE_UA(29b, 100b)
_ASM_EXTABLE_UA(30b, 100b)
_ASM_EXTABLE_UA(31b, 100b)
_ASM_EXTABLE_UA(32b, 100b)
_ASM_EXTABLE_UA(33b, 100b)
_ASM_EXTABLE_UA(34b, 100b)
_ASM_EXTABLE_UA(35b, 100b)
_ASM_EXTABLE_UA(36b, 100b)
_ASM_EXTABLE_UA(37b, 100b)
_ASM_EXTABLE_UA(99b, 101b)
: "=&c"(size), "=&D" (d0), "=&S" (d1)
: "1"(to), "2"(from), "0"(size)
: "eax", "edx", "memory");
@@ -259,26 +259,26 @@ static unsigned long __copy_user_intel_nocache(void *to,
"9: lea 0(%%eax,%0,4),%0\n"
"16: jmp 8b\n"
".previous\n"
_ASM_EXTABLE(0b,16b)
_ASM_EXTABLE(1b,16b)
_ASM_EXTABLE(2b,16b)
_ASM_EXTABLE(21b,16b)
_ASM_EXTABLE(3b,16b)
_ASM_EXTABLE(31b,16b)
_ASM_EXTABLE(4b,16b)
_ASM_EXTABLE(41b,16b)
_ASM_EXTABLE(10b,16b)
_ASM_EXTABLE(51b,16b)
_ASM_EXTABLE(11b,16b)
_ASM_EXTABLE(61b,16b)
_ASM_EXTABLE(12b,16b)
_ASM_EXTABLE(71b,16b)
_ASM_EXTABLE(13b,16b)
_ASM_EXTABLE(81b,16b)
_ASM_EXTABLE(14b,16b)
_ASM_EXTABLE(91b,16b)
_ASM_EXTABLE(6b,9b)
_ASM_EXTABLE(7b,16b)
_ASM_EXTABLE_UA(0b, 16b)
_ASM_EXTABLE_UA(1b, 16b)
_ASM_EXTABLE_UA(2b, 16b)
_ASM_EXTABLE_UA(21b, 16b)
_ASM_EXTABLE_UA(3b, 16b)
_ASM_EXTABLE_UA(31b, 16b)
_ASM_EXTABLE_UA(4b, 16b)
_ASM_EXTABLE_UA(41b, 16b)
_ASM_EXTABLE_UA(10b, 16b)
_ASM_EXTABLE_UA(51b, 16b)
_ASM_EXTABLE_UA(11b, 16b)
_ASM_EXTABLE_UA(61b, 16b)
_ASM_EXTABLE_UA(12b, 16b)
_ASM_EXTABLE_UA(71b, 16b)
_ASM_EXTABLE_UA(13b, 16b)
_ASM_EXTABLE_UA(81b, 16b)
_ASM_EXTABLE_UA(14b, 16b)
_ASM_EXTABLE_UA(91b, 16b)
_ASM_EXTABLE_UA(6b, 9b)
_ASM_EXTABLE_UA(7b, 16b)
: "=&c"(size), "=&D" (d0), "=&S" (d1)
: "1"(to), "2"(from), "0"(size)
: "eax", "edx", "memory");
@@ -321,9 +321,9 @@ do { \
"3: lea 0(%3,%0,4),%0\n" \
" jmp 2b\n" \
".previous\n" \
_ASM_EXTABLE(4b,5b) \
_ASM_EXTABLE(0b,3b) \
_ASM_EXTABLE(1b,2b) \
_ASM_EXTABLE_UA(4b, 5b) \
_ASM_EXTABLE_UA(0b, 3b) \
_ASM_EXTABLE_UA(1b, 2b) \
: "=&c"(size), "=&D" (__d0), "=&S" (__d1), "=r"(__d2) \
: "3"(size), "0"(size), "1"(to), "2"(from) \
: "memory"); \