android_kernel_xiaomi_sm8350/fs/jfs/ioctl.c
Satyam Sharma 3bd858ab1c Introduce is_owner_or_cap() to wrap CAP_FOWNER use with fsuid check
Introduce is_owner_or_cap() macro in fs.h, and convert over relevant
users to it. This is done because we want to avoid bugs in the future
where we check for only effective fsuid of the current task against a
file's owning uid, without simultaneously checking for CAP_FOWNER as
well, thus violating its semantics.
[ XFS uses special macros and structures, and in general looked ...
untouchable, so we leave it alone -- but it has been looked over. ]

The (current->fsuid != inode->i_uid) check in generic_permission() and
exec_permission_lite() is left alone, because those operations are
covered by CAP_DAC_OVERRIDE and CAP_DAC_READ_SEARCH. Similarly operations
falling under the purview of CAP_CHOWN and CAP_LEASE are also left alone.

Signed-off-by: Satyam Sharma <ssatyam@cse.iitk.ac.in>
Cc: Al Viro <viro@ftp.linux.org.uk>
Acked-by: Serge E. Hallyn <serge@hallyn.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17 12:00:03 -07:00

110 lines
2.2 KiB
C

/*
* linux/fs/jfs/ioctl.c
*
* Copyright (C) 2006 Herbert Poetzl
* adapted from Remy Card's ext2/ioctl.c
*/
#include <linux/fs.h>
#include <linux/ctype.h>
#include <linux/capability.h>
#include <linux/time.h>
#include <linux/sched.h>
#include <asm/current.h>
#include <asm/uaccess.h>
#include "jfs_incore.h"
#include "jfs_dinode.h"
#include "jfs_inode.h"
static struct {
long jfs_flag;
long ext2_flag;
} jfs_map[] = {
{JFS_NOATIME_FL, FS_NOATIME_FL},
{JFS_DIRSYNC_FL, FS_DIRSYNC_FL},
{JFS_SYNC_FL, FS_SYNC_FL},
{JFS_SECRM_FL, FS_SECRM_FL},
{JFS_UNRM_FL, FS_UNRM_FL},
{JFS_APPEND_FL, FS_APPEND_FL},
{JFS_IMMUTABLE_FL, FS_IMMUTABLE_FL},
{0, 0},
};
static long jfs_map_ext2(unsigned long flags, int from)
{
int index=0;
long mapped=0;
while (jfs_map[index].jfs_flag) {
if (from) {
if (jfs_map[index].ext2_flag & flags)
mapped |= jfs_map[index].jfs_flag;
} else {
if (jfs_map[index].jfs_flag & flags)
mapped |= jfs_map[index].ext2_flag;
}
index++;
}
return mapped;
}
int jfs_ioctl(struct inode * inode, struct file * filp, unsigned int cmd,
unsigned long arg)
{
struct jfs_inode_info *jfs_inode = JFS_IP(inode);
unsigned int flags;
switch (cmd) {
case JFS_IOC_GETFLAGS:
jfs_get_inode_flags(jfs_inode);
flags = jfs_inode->mode2 & JFS_FL_USER_VISIBLE;
flags = jfs_map_ext2(flags, 0);
return put_user(flags, (int __user *) arg);
case JFS_IOC_SETFLAGS: {
unsigned int oldflags;
if (IS_RDONLY(inode))
return -EROFS;
if (!is_owner_or_cap(inode))
return -EACCES;
if (get_user(flags, (int __user *) arg))
return -EFAULT;
flags = jfs_map_ext2(flags, 1);
if (!S_ISDIR(inode->i_mode))
flags &= ~JFS_DIRSYNC_FL;
jfs_get_inode_flags(jfs_inode);
oldflags = jfs_inode->mode2;
/*
* The IMMUTABLE and APPEND_ONLY flags can only be changed by
* the relevant capability.
*/
if ((oldflags & JFS_IMMUTABLE_FL) ||
((flags ^ oldflags) &
(JFS_APPEND_FL | JFS_IMMUTABLE_FL))) {
if (!capable(CAP_LINUX_IMMUTABLE))
return -EPERM;
}
flags = flags & JFS_FL_USER_MODIFIABLE;
flags |= oldflags & ~JFS_FL_USER_MODIFIABLE;
jfs_inode->mode2 = flags;
jfs_set_inode_flags(inode);
inode->i_ctime = CURRENT_TIME_SEC;
mark_inode_dirty(inode);
return 0;
}
default:
return -ENOTTY;
}
}