From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: =?UTF-8?q?Micka=C3=ABl=20Sala=C3=BCn?= Date: Sun, 29 Nov 2015 15:03:21 +0100 Message-Id: <1448805802-12156-2-git-send-email-mic@digikod.net> In-Reply-To: <1448805802-12156-1-git-send-email-mic@digikod.net> References: <1448805802-12156-1-git-send-email-mic@digikod.net> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Sender: linux-kernel-owner@vger.kernel.org Subject: [PATCH v2 1/2] um: Set secure access mode for temporary file To: linux-kernel@vger.kernel.org Cc: =?UTF-8?q?Micka=C3=ABl=20Sala=C3=BCn?= , Jeff Dike , Richard Weinberger , Tristan Schmelcher , Greg Kroah-Hartman , user-mode-linux-devel@lists.sourceforge.net, user-mode-linux-user@lists.sourceforge.net List-ID: Replace the insecure mode 0777 with 0700 for temporary file to prohibit other users to change the executable mapped code. An attacker could gain access to the mapped file descriptor from the temporary file (before it is unlinked) in a read-only mode but it shoul= d not be accessible in write mode to avoid arbitrary code execution. Signed-off-by: Micka=C3=ABl Sala=C3=BCn --- arch/um/os-Linux/mem.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/um/os-Linux/mem.c b/arch/um/os-Linux/mem.c index 897e9ad..798aeb4 100644 --- a/arch/um/os-Linux/mem.c +++ b/arch/um/os-Linux/mem.c @@ -142,7 +142,7 @@ static int __init create_tmp_file(unsigned long lon= g len) if (fd < 0) exit(1); =20 - err =3D fchmod(fd, 0777); + err =3D fchmod(fd, 0700); if (err < 0) { perror("fchmod"); exit(1); --=20 2.6.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel"= in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/