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From: "Mickaël Salaün" <mic@digikod.net>
To: linux-kernel@vger.kernel.org
Cc: "Mickaël Salaün" <mic@digikod.net>,
	"Jeff Dike" <jdike@addtoit.com>,
	"Richard Weinberger" <richard@nod.at>,
	"Tristan Schmelcher" <tschmelcher@google.com>,
	"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
	user-mode-linux-devel@lists.sourceforge.net,
	user-mode-linux-user@lists.sourceforge.net
Subject: [PATCH v3 2/2] um: Use race-free temporary file creation
Date: Thu, 10 Dec 2015 01:09:44 +0100	[thread overview]
Message-ID: <1449706184-19284-3-git-send-email-mic@digikod.net> (raw)
In-Reply-To: <1449706184-19284-1-git-send-email-mic@digikod.net>

Open the memory mapped file with the O_TMPFILE flag when available.

Signed-off-by: Mickaël Salaün <mic@digikod.net>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Acked-by: Tristan Schmelcher <tschmelcher@google.com>
---
 arch/um/os-Linux/mem.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/arch/um/os-Linux/mem.c b/arch/um/os-Linux/mem.c
index 840d573..8b17676 100644
--- a/arch/um/os-Linux/mem.c
+++ b/arch/um/os-Linux/mem.c
@@ -106,6 +106,17 @@ static int __init make_tempfile(const char *template)
 		}
 	}
 
+#ifdef O_TMPFILE
+	fd = open(tempdir, O_CLOEXEC | O_RDWR | O_EXCL | O_TMPFILE, 0700);
+	/*
+	 * If the running system does not support O_TMPFILE flag then retry
+	 * without it.
+	 */
+	if (fd != -1 || (errno != EINVAL && errno != EISDIR &&
+			errno != EOPNOTSUPP))
+		return fd;
+#endif
+
 	tempname = malloc(strlen(tempdir) + strlen(template) + 1);
 	if (tempname == NULL)
 		return -1;
-- 
2.6.2


WARNING: multiple messages have this Message-ID (diff)
From: "Mickaël Salaün" <mic@digikod.net>
To: linux-kernel@vger.kernel.org
Cc: "Mickaël Salaün" <mic@digikod.net>,
	"Jeff Dike" <jdike@addtoit.com>,
	"Richard Weinberger" <richard@nod.at>,
	"Tristan Schmelcher" <tschmelcher@google.com>,
	"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
	user-mode-linux-devel@lists.sourceforge.net,
	user-mode-linux-user@lists.sourceforge.net
Subject: [PATCH v3 2/2] um: Use race-free temporary file creation
Date: Thu, 10 Dec 2015 01:09:44 +0100	[thread overview]
Message-ID: <1449706184-19284-3-git-send-email-mic@digikod.net> (raw)
In-Reply-To: <1449706184-19284-1-git-send-email-mic@digikod.net>

Open the memory mapped file with the O_TMPFILE flag when available.

Signed-off-by: Mickaël Salaün <mic@digikod.net>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Acked-by: Tristan Schmelcher <tschmelcher@google.com>
---
 arch/um/os-Linux/mem.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/arch/um/os-Linux/mem.c b/arch/um/os-Linux/mem.c
index 840d573..8b17676 100644
--- a/arch/um/os-Linux/mem.c
+++ b/arch/um/os-Linux/mem.c
@@ -106,6 +106,17 @@ static int __init make_tempfile(const char *template)
 		}
 	}
 
+#ifdef O_TMPFILE
+	fd = open(tempdir, O_CLOEXEC | O_RDWR | O_EXCL | O_TMPFILE, 0700);
+	/*
+	 * If the running system does not support O_TMPFILE flag then retry
+	 * without it.
+	 */
+	if (fd != -1 || (errno != EINVAL && errno != EISDIR &&
+			errno != EOPNOTSUPP))
+		return fd;
+#endif
+
 	tempname = malloc(strlen(tempdir) + strlen(template) + 1);
 	if (tempname == NULL)
 		return -1;
-- 
2.6.2

--
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  parent reply	other threads:[~2015-12-10  1:28 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-12-10  0:09 [PATCH v3 0/2] um: Protect memory mapped file Mickaël Salaün
2015-12-10  0:09 ` Mickaël Salaün
2015-12-10  0:09 ` [PATCH v3 1/2] um: Do not set unsecure permission for temporary file Mickaël Salaün
2015-12-10  0:09   ` Mickaël Salaün
2015-12-11 19:24   ` Tristan Schmelcher
2015-12-10  0:09 ` Mickaël Salaün [this message]
2015-12-10  0:09   ` [PATCH v3 2/2] um: Use race-free temporary file creation Mickaël Salaün

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