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

[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
......@@ -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 @@ outrel:
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)
{
......
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