From: Jann Horn <jann@thejh.net>
To: security@kernel.org, Alexander Viro <viro@zeniv.linux.org.uk>,
Paul Moore <paul@paul-moore.com>,
Stephen Smalley <sds@tycho.nsa.gov>,
Eric Paris <eparis@parisplace.org>,
James Morris <james.l.morris@oracle.com>,
"Serge E. Hallyn" <serge@hallyn.com>
Cc: Nick Kralevich <nnk@google.com>,
Janis Danisevskis <jdanis@google.com>,
linux-security-module@vger.kernel.org, linux-mm@kvack.org,
linux-kernel@vger.kernel.org
Subject: [PATCH v2 1/3] fs/exec: don't force writing memory access
Date: Thu, 29 Sep 2016 00:54:39 +0200 [thread overview]
Message-ID: <1475103281-7989-2-git-send-email-jann@thejh.net> (raw)
In-Reply-To: <1475103281-7989-1-git-send-email-jann@thejh.net>
This shouldn't change behavior in any way - at this point, there should be
no non-writable mappings, only the initial stack mapping -, but this change
makes it easier to reason about the correctness of the following commits
that place restrictions on forced memory writes.
Signed-off-by: Jann Horn <jann@thejh.net>
Reviewed-by: Janis Danisevskis <jdanis@android.com>
---
fs/exec.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/exec.c b/fs/exec.c
index 6fcfb3f..d607da8 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -204,7 +204,7 @@ static struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos,
* doing the exec and bprm->mm is the new process's mm.
*/
ret = get_user_pages_remote(current, bprm->mm, pos, 1, write,
- 1, &page, NULL);
+ 0, &page, NULL);
if (ret <= 0)
return NULL;
--
2.1.4
--
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next prev parent reply other threads:[~2016-09-28 22:54 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-28 22:54 [PATCH v2 0/3] fix SELinux W^X bypass via ptrace Jann Horn
2016-09-28 22:54 ` Jann Horn [this message]
2016-09-29 16:09 ` [PATCH v2 1/3] fs/exec: don't force writing memory access Oleg Nesterov
2016-09-28 22:54 ` [PATCH v2 2/3] mm: add LSM hook for writes to readonly memory Jann Horn
2016-09-28 23:22 ` Andy Lutomirski
2016-09-28 23:32 ` Jann Horn
2016-09-28 23:44 ` Jann Horn
2016-11-03 2:25 ` Jann Horn
2016-09-29 6:25 ` Ingo Molnar
2016-09-28 22:54 ` [PATCH v2 3/3] selinux: require EXECMEM for forced ptrace poke Jann Horn
2016-09-29 6:19 ` Ingo Molnar
2016-09-29 16:38 ` Stephen Smalley
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