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Commit a761a1c0 authored by Dave Hansen's avatar Dave Hansen Committed by Al Viro
Browse files

[PATCH] r/o bind mounts: elevate write count for ncp_ioctl() 



Acked-by: default avatarAl Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarDave Hansen <haveblue@us.ibm.com>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 18f335af

fs/ncpfs/ioctl.c

+53 −1
Original line number Diff line number Diff line
@@ -14,6 +14,7 @@ 
#include <linux/ioctl.h>

#include <linux/time.h>

#include <linux/mm.h>

#include <linux/mount.h>

#include <linux/highuid.h>

#include <linux/smp_lock.h>

#include <linux/vmalloc.h>
@@ -261,7 +262,7 @@ ncp_get_charsets(struct ncp_server* server, struct ncp_nls_ioctl __user *arg) 
}

#endif /* CONFIG_NCPFS_NLS */



int ncp_ioctl(struct inode *inode, struct file *filp,

static int __ncp_ioctl(struct inode *inode, struct file *filp,

	      unsigned int cmd, unsigned long arg)

{

	struct ncp_server *server = NCP_SERVER(inode);
@@ -822,6 +823,57 @@ int ncp_ioctl(struct inode *inode, struct file *filp, 
	return -EINVAL;

}



static int ncp_ioctl_need_write(unsigned int cmd)

{

	switch (cmd) {

	case NCP_IOC_GET_FS_INFO:

	case NCP_IOC_GET_FS_INFO_V2:

	case NCP_IOC_NCPREQUEST:

	case NCP_IOC_SETDENTRYTTL:

	case NCP_IOC_SIGN_INIT:

	case NCP_IOC_LOCKUNLOCK:

	case NCP_IOC_SET_SIGN_WANTED:

		return 1;

	case NCP_IOC_GETOBJECTNAME:

	case NCP_IOC_SETOBJECTNAME:

	case NCP_IOC_GETPRIVATEDATA:

	case NCP_IOC_SETPRIVATEDATA:

	case NCP_IOC_SETCHARSETS:

	case NCP_IOC_GETCHARSETS:

	case NCP_IOC_CONN_LOGGED_IN:

	case NCP_IOC_GETDENTRYTTL:

	case NCP_IOC_GETMOUNTUID2:

	case NCP_IOC_SIGN_WANTED:

	case NCP_IOC_GETROOT:

	case NCP_IOC_SETROOT:

		return 0;

	default:

		/* unkown IOCTL command, assume write */

		return 1;

	}

}



int ncp_ioctl(struct inode *inode, struct file *filp,

	      unsigned int cmd, unsigned long arg)

{

	int ret;



	if (ncp_ioctl_need_write(cmd)) {

		/*

		 * inside the ioctl(), any failures which

		 * are because of file_permission() are

		 * -EACCESS, so it seems consistent to keep

		 *  that here.

		 */

		if (mnt_want_write(filp->f_path.mnt))

			return -EACCES;

	}

	ret = __ncp_ioctl(inode, filp, cmd, arg);

	if (ncp_ioctl_need_write(cmd))

		mnt_drop_write(filp->f_path.mnt);

	return ret;

}



#ifdef CONFIG_COMPAT

long ncp_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)

{