From: Florent Revest <revest@chromium.org>
To: linux-kernel@vger.kernel.org, linux-mm@kvack.org
Cc: akpm@linux-foundation.org, catalin.marinas@arm.com,
anshuman.khandual@arm.com, joey.gouly@arm.com, mhocko@suse.com,
keescook@chromium.org, david@redhat.com, peterx@redhat.com,
izbyshev@ispras.ru, broonie@kernel.org, szabolcs.nagy@arm.com,
kpsingh@kernel.org, gthelen@google.com, toiwoton@gmail.com,
ayush.jain3@amd.com, Florent Revest <revest@chromium.org>,
stable@vger.kernel.org
Subject: [PATCH v4 4/6] mm: Make PR_MDWE_REFUSE_EXEC_GAIN an unsigned long
Date: Mon, 28 Aug 2023 17:08:56 +0200 [thread overview]
Message-ID: <20230828150858.393570-5-revest@chromium.org> (raw)
In-Reply-To: <20230828150858.393570-1-revest@chromium.org>
Defining a prctl flag as an int is a footgun because on a 64 bit machine
and with a variadic implementation of prctl (like in musl and glibc),
when used directly as a prctl argument, it can get casted to long with
garbage upper bits which would result in unexpected behaviors.
This patch changes the constant to an unsigned long to eliminate that
possibilities. This does not break UAPI.
Fixes: b507808ebce2 ("mm: implement memory-deny-write-execute as a prctl")
Cc: stable@vger.kernel.org
Signed-off-by: Florent Revest <revest@chromium.org>
Suggested-by: Alexey Izbyshev <izbyshev@ispras.ru>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
---
include/uapi/linux/prctl.h | 2 +-
tools/include/uapi/linux/prctl.h | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/include/uapi/linux/prctl.h b/include/uapi/linux/prctl.h
index 3c36aeade991..9a85c69782bd 100644
--- a/include/uapi/linux/prctl.h
+++ b/include/uapi/linux/prctl.h
@@ -283,7 +283,7 @@ struct prctl_mm_map {
/* Memory deny write / execute */
#define PR_SET_MDWE 65
-# define PR_MDWE_REFUSE_EXEC_GAIN 1
+# define PR_MDWE_REFUSE_EXEC_GAIN (1UL << 0)
#define PR_GET_MDWE 66
diff --git a/tools/include/uapi/linux/prctl.h b/tools/include/uapi/linux/prctl.h
index 3c36aeade991..9a85c69782bd 100644
--- a/tools/include/uapi/linux/prctl.h
+++ b/tools/include/uapi/linux/prctl.h
@@ -283,7 +283,7 @@ struct prctl_mm_map {
/* Memory deny write / execute */
#define PR_SET_MDWE 65
-# define PR_MDWE_REFUSE_EXEC_GAIN 1
+# define PR_MDWE_REFUSE_EXEC_GAIN (1UL << 0)
#define PR_GET_MDWE 66
--
2.42.0.rc2.253.gd59a3bf2b4-goog
next prev parent reply other threads:[~2023-08-28 15:10 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-08-28 15:08 [PATCH v4 0/6] MDWE without inheritance Florent Revest
2023-08-28 15:08 ` [PATCH v4 1/6] kselftest: vm: Fix tabs/spaces inconsistency in the mdwe test Florent Revest
2023-08-28 15:08 ` [PATCH v4 2/6] kselftest: vm: Fix mdwe's mmap_FIXED test case Florent Revest
2023-08-28 15:08 ` [PATCH v4 3/6] kselftest: vm: Check errnos in mdwe_test Florent Revest
2023-08-28 18:45 ` Kees Cook
2023-09-21 9:51 ` Catalin Marinas
2023-08-28 15:08 ` Florent Revest [this message]
2023-09-22 1:29 ` [PATCH v4 4/6] mm: Make PR_MDWE_REFUSE_EXEC_GAIN an unsigned long Andrew Morton
2023-09-22 13:10 ` Florent Revest
2023-08-28 15:08 ` [PATCH v4 5/6] mm: Add a NO_INHERIT flag to the PR_SET_MDWE prctl Florent Revest
2023-09-22 1:33 ` Andrew Morton
2023-10-03 15:52 ` Florent Revest
2023-08-28 15:08 ` [PATCH v4 6/6] kselftest: vm: Add tests for no-inherit memory-deny-write-execute Florent Revest
2023-08-28 18:45 ` Kees Cook
2023-09-20 19:56 ` [PATCH v4 0/6] MDWE without inheritance Florent Revest
2023-09-21 9:52 ` Catalin Marinas
2023-09-21 9:57 ` Florent Revest
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