e47776a0a4
Forbid user from changing file flags on quota files. User has no bussiness in playing with these flags when quota is on. Furthermore there is a remote possibility of deadlock due to a lock inversion between quota file's i_mutex and transaction's start (i_mutex for quota file is locked only when trasaction is started in quota operations) in ext3 and ext4. Signed-off-by: Jan Kara <jack@suse.cz> Cc: LIOU Payphone <lioupayphone@gmail.com> Cc: <linux-ext4@vger.kernel.org> Acked-by: Dave Kleikamp <shaggy@austin.ibm.com> Cc: <reiserfs-dev@namesys.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
113 lines
2.3 KiB
C
113 lines
2.3 KiB
C
/*
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* linux/fs/jfs/ioctl.c
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*
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* Copyright (C) 2006 Herbert Poetzl
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* adapted from Remy Card's ext2/ioctl.c
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*/
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#include <linux/fs.h>
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#include <linux/ctype.h>
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#include <linux/capability.h>
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#include <linux/time.h>
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#include <linux/sched.h>
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#include <asm/current.h>
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#include <asm/uaccess.h>
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#include "jfs_incore.h"
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#include "jfs_dinode.h"
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#include "jfs_inode.h"
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static struct {
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long jfs_flag;
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long ext2_flag;
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} jfs_map[] = {
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{JFS_NOATIME_FL, FS_NOATIME_FL},
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{JFS_DIRSYNC_FL, FS_DIRSYNC_FL},
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{JFS_SYNC_FL, FS_SYNC_FL},
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{JFS_SECRM_FL, FS_SECRM_FL},
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{JFS_UNRM_FL, FS_UNRM_FL},
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{JFS_APPEND_FL, FS_APPEND_FL},
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{JFS_IMMUTABLE_FL, FS_IMMUTABLE_FL},
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{0, 0},
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};
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static long jfs_map_ext2(unsigned long flags, int from)
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{
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int index=0;
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long mapped=0;
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while (jfs_map[index].jfs_flag) {
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if (from) {
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if (jfs_map[index].ext2_flag & flags)
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mapped |= jfs_map[index].jfs_flag;
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} else {
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if (jfs_map[index].jfs_flag & flags)
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mapped |= jfs_map[index].ext2_flag;
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}
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index++;
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}
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return mapped;
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}
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int jfs_ioctl(struct inode * inode, struct file * filp, unsigned int cmd,
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unsigned long arg)
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{
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struct jfs_inode_info *jfs_inode = JFS_IP(inode);
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unsigned int flags;
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switch (cmd) {
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case JFS_IOC_GETFLAGS:
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jfs_get_inode_flags(jfs_inode);
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flags = jfs_inode->mode2 & JFS_FL_USER_VISIBLE;
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flags = jfs_map_ext2(flags, 0);
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return put_user(flags, (int __user *) arg);
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case JFS_IOC_SETFLAGS: {
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unsigned int oldflags;
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if (IS_RDONLY(inode))
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return -EROFS;
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if (!is_owner_or_cap(inode))
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return -EACCES;
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if (get_user(flags, (int __user *) arg))
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return -EFAULT;
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flags = jfs_map_ext2(flags, 1);
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if (!S_ISDIR(inode->i_mode))
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flags &= ~JFS_DIRSYNC_FL;
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/* Is it quota file? Do not allow user to mess with it */
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if (IS_NOQUOTA(inode))
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return -EPERM;
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jfs_get_inode_flags(jfs_inode);
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oldflags = jfs_inode->mode2;
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/*
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* The IMMUTABLE and APPEND_ONLY flags can only be changed by
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* the relevant capability.
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*/
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if ((oldflags & JFS_IMMUTABLE_FL) ||
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((flags ^ oldflags) &
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(JFS_APPEND_FL | JFS_IMMUTABLE_FL))) {
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if (!capable(CAP_LINUX_IMMUTABLE))
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return -EPERM;
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}
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flags = flags & JFS_FL_USER_MODIFIABLE;
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flags |= oldflags & ~JFS_FL_USER_MODIFIABLE;
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jfs_inode->mode2 = flags;
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jfs_set_inode_flags(inode);
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inode->i_ctime = CURRENT_TIME_SEC;
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mark_inode_dirty(inode);
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return 0;
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}
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default:
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return -ENOTTY;
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}
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}
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