Commit 34b07840 authored by Djalal Harouni's avatar Djalal Harouni Committed by Jan Kara
Browse files

ext2: protect inode changes in the SETVERSION and SETFLAGS ioctls 



Unlock mutex after i_flags and i_ctime updates in the EXT2_IOC_SETFLAGS
ioctl.

Use i_mutex in the EXT2_IOC_SETVERSION ioctl to protect i_ctime and
i_generation updates and make the ioctl consistent since i_mutex is
also used in other places to protect timestamps and inode changes.

Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: default avatarDjalal Harouni <tixxdz@opendz.org>
Signed-off-by: default avatarJan Kara <jack@suse.cz>
parent 353b67d8

fs/ext2/ioctl.c

+16 −6
Original line number Diff line number Diff line
@@ -77,10 +77,11 @@ long ext2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) 
		flags = flags & EXT2_FL_USER_MODIFIABLE;

		flags |= oldflags & ~EXT2_FL_USER_MODIFIABLE;

		ei->i_flags = flags;

		mutex_unlock(&inode->i_mutex);



		ext2_set_inode_flags(inode);

		inode->i_ctime = CURRENT_TIME_SEC;

		mutex_unlock(&inode->i_mutex);



		mark_inode_dirty(inode);

setflags_out:

		mnt_drop_write_file(filp);
@@ -88,20 +89,29 @@ setflags_out: 
	}

	case EXT2_IOC_GETVERSION:

		return put_user(inode->i_generation, (int __user *) arg);

	case EXT2_IOC_SETVERSION:

	case EXT2_IOC_SETVERSION: {

		__u32 generation;



		if (!inode_owner_or_capable(inode))

			return -EPERM;

		ret = mnt_want_write_file(filp);

		if (ret)

			return ret;

		if (get_user(inode->i_generation, (int __user *) arg)) {

		if (get_user(generation, (int __user *) arg)) {

			ret = -EFAULT;

		} else {

			goto setversion_out;

		}



		mutex_lock(&inode->i_mutex);

		inode->i_ctime = CURRENT_TIME_SEC;

		inode->i_generation = generation;

		mutex_unlock(&inode->i_mutex);



		mark_inode_dirty(inode);

		}

setversion_out:

		mnt_drop_write_file(filp);

		return ret;

	}

	case EXT2_IOC_GETRSVSZ:

		if (test_opt(inode->i_sb, RESERVATION)

			&& S_ISREG(inode->i_mode)

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