linux/arch/x86/entry
Thomas Garnier 5ea0727b16 x86/syscalls: Check address limit on user-mode return
Ensure the address limit is a user-mode segment before returning to
user-mode. Otherwise a process can corrupt kernel-mode memory and elevate
privileges [1].

The set_fs function sets the TIF_SETFS flag to force a slow path on
return. In the slow path, the address limit is checked to be USER_DS if
needed.

The addr_limit_user_check function is added as a cross-architecture
function to check the address limit.

[1] https://bugs.chromium.org/p/project-zero/issues/detail?id=990

Signed-off-by: Thomas Garnier <thgarnie@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: kernel-hardening@lists.openwall.com
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Miroslav Benes <mbenes@suse.cz>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Pratyush Anand <panand@redhat.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Will Drewry <wad@chromium.org>
Cc: linux-api@vger.kernel.org
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Link: http://lkml.kernel.org/r/20170615011203.144108-1-thgarnie@google.com
2017-07-08 14:05:32 +02:00
..
syscalls Merge branch 'work.compat' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-05-02 11:54:26 -07:00
vdso Merge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-05-01 23:54:56 -07:00
vsyscall sched/headers: Prepare to remove the <linux/mm_types.h> dependency from <linux/sched.h> 2017-03-02 08:42:37 +01:00
calling.h x86/entry/unwind: Create stack frames for saved interrupt registers 2016-10-21 09:26:03 +02:00
common.c x86/syscalls: Check address limit on user-mode return 2017-07-08 14:05:32 +02:00
entry_32.S Revert "x86/entry: Fix the end of the stack for newly forked tasks" 2017-05-24 09:05:16 +02:00
entry_64_compat.S x86/asm/entry/32: Simplify pushes of zeroed pt_regs->REGs 2016-05-03 08:19:40 +02:00
entry_64.S x86/asm: Fix comment in return_from_SYSCALL_64() 2017-06-13 08:56:51 +02:00
Makefile x86/build: Fix build with older GCC versions 2016-10-25 11:44:25 +02:00
syscall_32.c x86/syscalls: Add syscall entry qualifiers 2016-01-29 09:46:38 +01:00
syscall_64.c x86/entry/64: Always run ptregs-using syscalls on the slow path 2016-01-29 09:46:38 +01:00
thunk_32.S x86: move exports to actual definitions 2016-08-07 23:47:15 -04:00
thunk_64.S x86: move exports to actual definitions 2016-08-07 23:47:15 -04:00