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From: Dave Hansen <haveblue@us.ibm.com>
To: linux-kernel@vger.kernel.org
Cc: viro@ftp.linux.org.uk, herbert@13thfloor.at, hch@infradead.org,
	Dave Hansen <haveblue@us.ibm.com>
Subject: [PATCH 15/28] elevate mount count for extended attributes
Date: Tue, 01 Aug 2006 16:52:51 -0700	[thread overview]
Message-ID: <20060801235251.D026F240@localhost.localdomain> (raw)
In-Reply-To: <20060801235240.82ADCA42@localhost.localdomain>


This basically audits the callers of xattr_permission(), which
calls permission() and can perform writes to the filesystem.

Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
---

 lxc-dave/fs/nfsd/nfs4proc.c |    7 ++++++-
 lxc-dave/fs/xattr.c         |   14 ++++++++++++++
 2 files changed, 20 insertions(+), 1 deletion(-)

diff -puN fs/nfsd/nfs4proc.c~C-xattr fs/nfsd/nfs4proc.c
--- lxc/fs/nfsd/nfs4proc.c~C-xattr	2006-08-01 16:35:09.000000000 -0700
+++ lxc-dave/fs/nfsd/nfs4proc.c	2006-08-01 16:35:25.000000000 -0700
@@ -604,13 +604,18 @@ nfsd4_setattr(struct svc_rqst *rqstp, st
 			return status;
 		}
 	}
+	status = mnt_want_write(current_fh->fh_export->ex_mnt);
+	if (status)
+		return status;
 	status = nfs_ok;
 	if (setattr->sa_acl != NULL)
 		status = nfsd4_set_nfs4_acl(rqstp, current_fh, setattr->sa_acl);
 	if (status)
-		return status;
+		goto out;
 	status = nfsd_setattr(rqstp, current_fh, &setattr->sa_iattr,
 				0, (time_t)0);
+out:
+	mnt_drop_write(current_fh->fh_export->ex_mnt);
 	return status;
 }
 
diff -puN fs/xattr.c~C-xattr fs/xattr.c
--- lxc/fs/xattr.c~C-xattr	2006-08-01 16:35:09.000000000 -0700
+++ lxc-dave/fs/xattr.c	2006-08-01 16:35:25.000000000 -0700
@@ -12,6 +12,7 @@
 #include <linux/smp_lock.h>
 #include <linux/file.h>
 #include <linux/xattr.h>
+#include <linux/mount.h>
 #include <linux/namei.h>
 #include <linux/security.h>
 #include <linux/syscalls.h>
@@ -210,7 +211,11 @@ sys_setxattr(char __user *path, char __u
 	error = user_path_walk(path, &nd);
 	if (error)
 		return error;
+	error = mnt_want_write(nd.mnt);
+	if (error)
+		return error;
 	error = setxattr(nd.dentry, name, value, size, flags);
+	mnt_drop_write(nd.mnt);
 	path_release(&nd);
 	return error;
 }
@@ -225,7 +230,11 @@ sys_lsetxattr(char __user *path, char __
 	error = user_path_walk_link(path, &nd);
 	if (error)
 		return error;
+	error = mnt_want_write(nd.mnt);
+	if (error)
+		return error;
 	error = setxattr(nd.dentry, name, value, size, flags);
+	mnt_drop_write(nd.mnt);
 	path_release(&nd);
 	return error;
 }
@@ -241,9 +250,14 @@ sys_fsetxattr(int fd, char __user *name,
 	f = fget(fd);
 	if (!f)
 		return error;
+	error = mnt_want_write(f->f_vfsmnt);
+	if (error)
+		goto out_fput;
 	dentry = f->f_dentry;
 	audit_inode(NULL, dentry->d_inode);
 	error = setxattr(dentry, name, value, size, flags);
+	mnt_drop_write(f->f_vfsmnt);
+out_fput:
 	fput(f);
 	return error;
 }
_

  parent reply	other threads:[~2006-08-02  0:01 UTC|newest]

Thread overview: 43+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-08-01 23:52 [PATCH 00/28] Mount writer count and read-only bind mounts (v5) Dave Hansen
2006-08-01 23:52 ` [PATCH 01/28] prepare for write access checks: collapse if() Dave Hansen
2006-08-03 14:32   ` Christoph Hellwig
2006-08-01 23:52 ` [PATCH 02/28] r/o bind mount prepwork: move open_namei()'s vfs_create() Dave Hansen
2006-08-03 14:33   ` Christoph Hellwig
2006-08-01 23:52 ` [PATCH 03/28] unlink: monitor i_nlink Dave Hansen
2006-08-03 14:35   ` Christoph Hellwig
2006-08-01 23:52 ` [PATCH 05/28] monitor zeroing of i_nlink Dave Hansen
2006-08-01 23:52 ` [PATCH 04/28] OCFS2 is screwy Dave Hansen
2006-08-02  2:14   ` Mark Fasheh
2006-08-02  3:19     ` [PATCH 04/28] OCFS2 is (not) screwy Dave Hansen
2006-08-02  3:21     ` [PATCH 04/28] OCFS2 is screwy Dave Hansen
2006-08-02  4:34       ` Mark Fasheh
2006-08-03  0:20       ` Mark Fasheh
2006-08-04 21:01         ` [PATCH] clean up OCFS2 nlink handling Dave Hansen
2006-08-04 21:38           ` Mark Fasheh
2006-08-01 23:52 ` [PATCH 06/28] reintroduce list of vfsmounts over superblock Dave Hansen
2006-08-03 14:39   ` Christoph Hellwig
2006-08-04 21:47     ` Dave Hansen
2006-08-01 23:52 ` [PATCH 07/28] Add vfsmount writer count Dave Hansen
2006-08-01 23:52 ` [PATCH 09/28] kill open files traverse on remount ro Dave Hansen
2006-08-01 23:52 ` [PATCH 08/28] record when sb_writer_count elevated for inode Dave Hansen
2006-08-01 23:52 ` [PATCH 10/28] increment sb writer count when nlink hits zero Dave Hansen
2006-08-01 23:52 ` [PATCH 11/28] elevate writer count for chown and friends Dave Hansen
2006-08-01 23:52 ` [PATCH 12/28] elevate mnt writers for callers of vfs_mkdir() Dave Hansen
2006-08-01 23:52 ` [PATCH 13/28] elevate write count during entire ncp_ioctl() Dave Hansen
2006-08-01 23:52 ` [PATCH 14/28] sys_symlinkat() elevate write count around vfs_symlink() Dave Hansen
2006-08-01 23:52 ` Dave Hansen [this message]
2006-08-01 23:52 ` [PATCH 16/28] sys_linkat(): elevate write count around vfs_link() Dave Hansen
2006-08-01 23:52 ` [PATCH 17/28] mount_is_safe(): add comment Dave Hansen
2006-08-01 23:52 ` [PATCH 18/28] unix_find_other() elevate write count for touch_atime() Dave Hansen
2006-08-01 23:52 ` [PATCH 19/28] elevate write count over calls to vfs_rename() Dave Hansen
2006-08-01 23:52 ` [PATCH 20/28] tricky: elevate write count files are open()ed Dave Hansen
2006-08-01 23:52 ` [PATCH 21/28] elevate writer count for do_sys_truncate() Dave Hansen
2006-08-01 23:52 ` [PATCH 22/28] elevate write count for do_utimes() Dave Hansen
2006-08-01 23:52 ` [PATCH 23/28] elevate write count for do_sys_utime() and touch_atime() Dave Hansen
2006-08-01 23:52 ` [PATCH 24/28] sys_mknodat(): elevate write count for vfs_mknod/create() Dave Hansen
2006-08-01 23:52 ` [PATCH 25/28] elevate mnt writers for vfs_unlink() callers Dave Hansen
2006-08-01 23:52 ` [PATCH 26/28] do_rmdir(): elevate write count Dave Hansen
2006-08-01 23:53 ` [PATCH 27/28] elevate writer count for custom 'struct file' Dave Hansen
2006-08-03 14:42   ` Christoph Hellwig
2006-08-11 20:31     ` Dave Hansen
2006-08-01 23:53 ` [PATCH 28/28] honor r/w changes at do_remount() time Dave Hansen

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