diff options
author | Thomas Garnier <thgarnie@google.com> | 2017-06-14 18:12:03 -0700 |
---|---|---|
committer | Thomas Gleixner <tglx@linutronix.de> | 2017-07-08 14:05:33 +0200 |
commit | cf7de27ab35172a9240f079477cae3146a182998 (patch) | |
tree | cd32efb78ea45ddba04b02774c5d57a3e1b6dfa2 /arch/arm64/kernel/signal.c | |
parent | 73ac5d6a2b6ac3ae8d1e1818f3e9946f97489bc9 (diff) | |
download | linux-stable-cf7de27ab35172a9240f079477cae3146a182998.tar.gz linux-stable-cf7de27ab35172a9240f079477cae3146a182998.tar.bz2 linux-stable-cf7de27ab35172a9240f079477cae3146a182998.zip |
arm64/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.
[1] https://bugs.chromium.org/p/project-zero/issues/detail?id=990
Signed-off-by: Thomas Garnier <thgarnie@google.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: kernel-hardening@lists.openwall.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/20170615011203.144108-3-thgarnie@google.com
Diffstat (limited to 'arch/arm64/kernel/signal.c')
-rw-r--r-- | arch/arm64/kernel/signal.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c index c7b6de62f9d3..0f0279148bdc 100644 --- a/arch/arm64/kernel/signal.c +++ b/arch/arm64/kernel/signal.c @@ -25,6 +25,7 @@ #include <linux/uaccess.h> #include <linux/tracehook.h> #include <linux/ratelimit.h> +#include <linux/syscalls.h> #include <asm/debug-monitors.h> #include <asm/elf.h> @@ -408,6 +409,10 @@ asmlinkage void do_notify_resume(struct pt_regs *regs, * Update the trace code with the current status. */ trace_hardirqs_off(); + + /* Check valid user FS if needed */ + addr_limit_user_check(); + do { if (thread_flags & _TIF_NEED_RESCHED) { schedule(); |