From: Kees Cook <keescook@chromium.org>
To: Ingo Molnar <mingo@kernel.org>
Cc: Kees Cook <keescook@chromium.org>,
Thomas Garnier <thgarnie@google.com>,
Thomas Gleixner <tglx@linutronix.de>,
Russell King <linux@armlinux.org.uk>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will.deacon@arm.com>,
Andy Lutomirski <luto@amacapital.net>,
Will Drewry <wad@chromium.org>, Al Viro <viro@zeniv.linux.org.uk>,
Dave Martin <Dave.Martin@arm.com>,
Pratyush Anand <panand@redhat.com>,
Dave Hansen <dave.hansen@intel.com>,
Arnd Bergmann <arnd@arndb.de>,
David Howells <dhowells@redhat.com>, Yonghong Song <yhs@fb.com>,
linux-arm-kernel@lists.infradead.org, linux-api@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: [PATCH 4/4] arm64/syscalls: Move address limit check in loop
Date: Thu, 7 Sep 2017 08:30:47 -0700 [thread overview]
Message-ID: <1504798247-48833-5-git-send-email-keescook@chromium.org> (raw)
In-Reply-To: <1504798247-48833-1-git-send-email-keescook@chromium.org>
From: Thomas Garnier <thgarnie@google.com>
A bug was reported on ARM where set_fs might be called after it was
checked on the work pending function. ARM64 is not affected by this bug
but has a similar construct. In order to avoid any similar problems in
the future, the addr_limit_user_check function is moved at the beginning
of the loop.
Fixes: cf7de27ab351 ("arm64/syscalls: Check address limit on user-mode return")
Reported-by: Leonard Crestez <leonard.crestez@nxp.com>
Signed-off-by: Thomas Garnier <thgarnie@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
---
arch/arm64/kernel/signal.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c
index c45214f8fb54..0bdc96c61bc0 100644
--- a/arch/arm64/kernel/signal.c
+++ b/arch/arm64/kernel/signal.c
@@ -751,10 +751,10 @@ asmlinkage void do_notify_resume(struct pt_regs *regs,
*/
trace_hardirqs_off();
- /* Check valid user FS if needed */
- addr_limit_user_check();
-
do {
+ /* Check valid user FS if needed */
+ addr_limit_user_check();
+
if (thread_flags & _TIF_NEED_RESCHED) {
schedule();
} else {
--
2.7.4
next prev parent reply other threads:[~2017-09-07 15:30 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-09-07 15:30 [PATCH 0/4] Fix check address limit on user-mode Kees Cook
2017-09-07 15:30 ` [PATCH 1/4] syscalls: Use CHECK_DATA_CORRUPTION for addr_limit_user_check Kees Cook
2017-09-07 15:30 ` [PATCH 2/4] Revert "arm/syscalls: Check address limit on user-mode return" Kees Cook
2017-09-07 15:30 ` [PATCH 3/4] arm/syscalls: Optimize address limit check Kees Cook
2017-09-07 15:30 ` Kees Cook [this message]
2017-09-12 18:27 ` [PATCH 4/4] arm64/syscalls: Move address limit check in loop Will Deacon
[not found] ` <20170912182727.GB27652-5wv7dgnIgG8@public.gmane.org>
2017-09-12 18:28 ` Kees Cook
2017-09-13 8:00 ` Ingo Molnar
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