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[PATCH 10/13] xfs: use get_unused_fd_flags(0) instead of get_unused_fd()

To: linux-kernel@xxxxxxxxxxxxxxx, xfs@xxxxxxxxxxx
Subject: [PATCH 10/13] xfs: use get_unused_fd_flags(0) instead of get_unused_fd()
From: Yann Droneaud <ydroneaud@xxxxxxxxxx>
Date: Tue, 2 Jul 2013 18:39:34 +0200
Cc: Yann Droneaud <ydroneaud@xxxxxxxxxx>
Delivered-to: xfs@xxxxxxxxxxx
In-reply-to: <cover.1372777600.git.ydroneaud@xxxxxxxxxx>
In-reply-to: <cover.1372777600.git.ydroneaud@xxxxxxxxxx>
References: <cover.1372777600.git.ydroneaud@xxxxxxxxxx>
References: <cover.1372777600.git.ydroneaud@xxxxxxxxxx>
Macro get_unused_fd() is used to allocate a file descriptor with
default flags. Those default flags (0) can be "unsafe":
O_CLOEXEC must be used by default to not leak file descriptor
across exec().

Instead of macro get_unused_fd(), functions anon_inode_getfd()
or get_unused_fd_flags() should be used with flags given by userspace.
If not possible, flags should be set to O_CLOEXEC to provide userspace
with a default safe behavor.

In a further patch, get_unused_fd() will be removed so that
new code start using anon_inode_getfd() or get_unused_fd_flags()
with correct flags.

This patch replaces calls to get_unused_fd() with equivalent call to
get_unused_fd_flags(0) to preserve current behavor for existing code.

The hard coded flag value (0) should be reviewed on a per-subsystem basis,
and, if possible, set to O_CLOEXEC.

Signed-off-by: Yann Droneaud <ydroneaud@xxxxxxxxxx>
---
 fs/xfs/xfs_ioctl.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c
index 5e99968..dc5b659 100644
--- a/fs/xfs/xfs_ioctl.c
+++ b/fs/xfs/xfs_ioctl.c
@@ -248,7 +248,7 @@ xfs_open_by_handle(
                goto out_dput;
        }
 
-       fd = get_unused_fd();
+       fd = get_unused_fd_flags(0);
        if (fd < 0) {
                error = fd;
                goto out_dput;
-- 
1.8.3.1

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