[PATCH v6 4/6] ima: use fs method to read integrity data

Dmitry Kasatkin dmitry.kasatkin at gmail.com
Tue Aug 22 10:09:13 UTC 2017


Looks good to me.


On Tue, Aug 15, 2017 at 5:43 PM, Mimi Zohar <zohar at linux.vnet.ibm.com> wrote:
> From: Christoph Hellwig <hch at lst.de>
>
> Add a new ->integrity_read file operation to read data for integrity
> hash collection.  This is defined to be equivalent to ->read_iter,
> except that it will be called with the i_rwsem held exclusively.
>
> (Based on Christoph's original patch.)
>
> Signed-off-by: Christoph Hellwig <hch at lst.de>
> Cc: Matthew Garrett <mjg59 at srcf.ucam.org>
> Cc: Jan Kara <jack at suse.com>
> Cc: "Theodore Ts'o" <tytso at mit.edu>
> Cc: Andreas Dilger <adilger.kernel at dilger.ca>
> Cc: Jaegeuk Kim <jaegeuk at kernel.org>
> Cc: Chao Yu <yuchao0 at huawei.com>
> Cc: Steven Whitehouse <swhiteho at redhat.com>
> Cc: Bob Peterson <rpeterso at redhat.com>
> Cc: David Woodhouse <dwmw2 at infradead.org>
> Cc: Dave Kleikamp <shaggy at kernel.org>
> Cc: Ryusuke Konishi <konishi.ryusuke at lab.ntt.co.jp>
> Cc: Mark Fasheh <mfasheh at versity.com>
> Cc: Joel Becker <jlbec at evilplan.org>
> Cc: Richard Weinberger <richard at nod.at>
> Cc: "Darrick J. Wong" <darrick.wong at oracle.com>
> Cc: Hugh Dickins <hughd at google.com>
> Cc: Chris Mason <clm at fb.com>
> Signed-off-by: Mimi Zohar <zohar at linux.vnet.ibm.com>
>
> ---
> Changelog v6:
> - defined separate efivarfs and libfs patches.
>
> Changelog v5:
> - removed ocf2 and gfs2 integrity_read support.
> - removed ext4 special case to fail O_DIRECT open for buffered read.
>
> Changelog v4:
> - define ext2/4 specific ->integrity_read functions.
> - properly fail file open with O_DIRECT on filesystem not mounted
> with "-o dax".
>
> Changelog v3:
> - define simple_read_iter_from_buffer
> - replace the existing efivarfs ->read method with ->read_iter method.
> - squashed other fs definitions of ->integrity_read with this patch.
>
> Changelog v2:
> - change iovec to kvec
>
> Changelog v1:
> - update the patch description, removing the concept that the presence of
> ->integrity_read indicates that the file system can support IMA. (Mimi)
>
>  fs/btrfs/file.c           |  1 +
>  fs/efivarfs/file.c        |  1 +
>  fs/ext2/file.c            | 17 +++++++++++++++++
>  fs/ext4/file.c            | 20 ++++++++++++++++++++
>  fs/f2fs/file.c            |  1 +
>  fs/jffs2/file.c           |  1 +
>  fs/jfs/file.c             |  1 +
>  fs/nilfs2/file.c          |  1 +
>  fs/ramfs/file-mmu.c       |  1 +
>  fs/ramfs/file-nommu.c     |  1 +
>  fs/ubifs/file.c           |  1 +
>  fs/xfs/xfs_file.c         | 21 +++++++++++++++++++++
>  include/linux/fs.h        |  1 +
>  mm/shmem.c                |  1 +
>  security/integrity/iint.c | 20 ++++++++++++++------
>  15 files changed, 83 insertions(+), 6 deletions(-)
>
> diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
> index 9e75d8a39aac..2542dc66c85c 100644
> --- a/fs/btrfs/file.c
> +++ b/fs/btrfs/file.c
> @@ -3125,6 +3125,7 @@ const struct file_operations btrfs_file_operations = {
>  #endif
>         .clone_file_range = btrfs_clone_file_range,
>         .dedupe_file_range = btrfs_dedupe_file_range,
> +       .integrity_read = generic_file_read_iter,
>  };
>
>  void btrfs_auto_defrag_exit(void)
> diff --git a/fs/efivarfs/file.c b/fs/efivarfs/file.c
> index 863f1b100165..17955a92a5b3 100644
> --- a/fs/efivarfs/file.c
> +++ b/fs/efivarfs/file.c
> @@ -179,4 +179,5 @@ const struct file_operations efivarfs_file_operations = {
>         .write  = efivarfs_file_write,
>         .llseek = no_llseek,
>         .unlocked_ioctl = efivarfs_file_ioctl,
> +       .integrity_read = efivarfs_file_read_iter,
>  };
> diff --git a/fs/ext2/file.c b/fs/ext2/file.c
> index d34d32bdc944..111069de1973 100644
> --- a/fs/ext2/file.c
> +++ b/fs/ext2/file.c
> @@ -192,6 +192,22 @@ static ssize_t ext2_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
>         return generic_file_read_iter(iocb, to);
>  }
>
> +static ssize_t ext2_file_integrity_read_iter(struct kiocb *iocb,
> +                                            struct iov_iter *to)
> +{
> +       struct inode *inode = file_inode(iocb->ki_filp);
> +
> +       lockdep_assert_held(&inode->i_rwsem);
> +#ifdef CONFIG_FS_DAX
> +       if (!iov_iter_count(to))
> +               return 0; /* skip atime */
> +
> +       if (IS_DAX(iocb->ki_filp->f_mapping->host))
> +               return dax_iomap_rw(iocb, to, &ext2_iomap_ops);
> +#endif
> +       return generic_file_read_iter(iocb, to);
> +}
> +
>  static ssize_t ext2_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
>  {
>  #ifdef CONFIG_FS_DAX
> @@ -216,6 +232,7 @@ const struct file_operations ext2_file_operations = {
>         .get_unmapped_area = thp_get_unmapped_area,
>         .splice_read    = generic_file_splice_read,
>         .splice_write   = iter_file_splice_write,
> +       .integrity_read = ext2_file_integrity_read_iter,
>  };
>
>  const struct inode_operations ext2_file_inode_operations = {
> diff --git a/fs/ext4/file.c b/fs/ext4/file.c
> index 58294c9a7e1d..3ab4105c8578 100644
> --- a/fs/ext4/file.c
> +++ b/fs/ext4/file.c
> @@ -74,6 +74,25 @@ static ssize_t ext4_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
>         return generic_file_read_iter(iocb, to);
>  }
>
> +static ssize_t ext4_file_integrity_read_iter(struct kiocb *iocb,
> +                                            struct iov_iter *to)
> +{
> +       struct inode *inode = file_inode(iocb->ki_filp);
> +
> +       lockdep_assert_held(&inode->i_rwsem);
> +       if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
> +               return -EIO;
> +
> +       if (!iov_iter_count(to))
> +               return 0; /* skip atime */
> +
> +#ifdef CONFIG_FS_DAX
> +       if (IS_DAX(inode))
> +               return dax_iomap_rw(iocb, to, &ext4_iomap_ops);
> +#endif
> +       return generic_file_read_iter(iocb, to);
> +}
> +
>  /*
>   * Called when an inode is released. Note that this is different
>   * from ext4_file_open: open gets called at every open, but release
> @@ -747,6 +766,7 @@ const struct file_operations ext4_file_operations = {
>         .splice_read    = generic_file_splice_read,
>         .splice_write   = iter_file_splice_write,
>         .fallocate      = ext4_fallocate,
> +       .integrity_read = ext4_file_integrity_read_iter,
>  };
>
>  const struct inode_operations ext4_file_inode_operations = {
> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
> index 2706130c261b..82ea81da0b2d 100644
> --- a/fs/f2fs/file.c
> +++ b/fs/f2fs/file.c
> @@ -2514,4 +2514,5 @@ const struct file_operations f2fs_file_operations = {
>  #endif
>         .splice_read    = generic_file_splice_read,
>         .splice_write   = iter_file_splice_write,
> +       .integrity_read = generic_file_read_iter,
>  };
> diff --git a/fs/jffs2/file.c b/fs/jffs2/file.c
> index c12476e309c6..5a63034cccf5 100644
> --- a/fs/jffs2/file.c
> +++ b/fs/jffs2/file.c
> @@ -57,6 +57,7 @@ const struct file_operations jffs2_file_operations =
>         .mmap =         generic_file_readonly_mmap,
>         .fsync =        jffs2_fsync,
>         .splice_read =  generic_file_splice_read,
> +       .integrity_read = generic_file_read_iter,
>  };
>
>  /* jffs2_file_inode_operations */
> diff --git a/fs/jfs/file.c b/fs/jfs/file.c
> index 739492c7a3fd..423512a810e4 100644
> --- a/fs/jfs/file.c
> +++ b/fs/jfs/file.c
> @@ -162,4 +162,5 @@ const struct file_operations jfs_file_operations = {
>  #ifdef CONFIG_COMPAT
>         .compat_ioctl   = jfs_compat_ioctl,
>  #endif
> +       .integrity_read = generic_file_read_iter,
>  };
> diff --git a/fs/nilfs2/file.c b/fs/nilfs2/file.c
> index c5fa3dee72fc..55e058ac487f 100644
> --- a/fs/nilfs2/file.c
> +++ b/fs/nilfs2/file.c
> @@ -150,6 +150,7 @@ const struct file_operations nilfs_file_operations = {
>         /* .release     = nilfs_release_file, */
>         .fsync          = nilfs_sync_file,
>         .splice_read    = generic_file_splice_read,
> +       .integrity_read = generic_file_read_iter,
>  };
>
>  const struct inode_operations nilfs_file_inode_operations = {
> diff --git a/fs/ramfs/file-mmu.c b/fs/ramfs/file-mmu.c
> index 12af0490322f..4f24d1b589b1 100644
> --- a/fs/ramfs/file-mmu.c
> +++ b/fs/ramfs/file-mmu.c
> @@ -47,6 +47,7 @@ const struct file_operations ramfs_file_operations = {
>         .splice_write   = iter_file_splice_write,
>         .llseek         = generic_file_llseek,
>         .get_unmapped_area      = ramfs_mmu_get_unmapped_area,
> +       .integrity_read = generic_file_read_iter,
>  };
>
>  const struct inode_operations ramfs_file_inode_operations = {
> diff --git a/fs/ramfs/file-nommu.c b/fs/ramfs/file-nommu.c
> index 2ef7ce75c062..5ee704fa84e0 100644
> --- a/fs/ramfs/file-nommu.c
> +++ b/fs/ramfs/file-nommu.c
> @@ -50,6 +50,7 @@ const struct file_operations ramfs_file_operations = {
>         .splice_read            = generic_file_splice_read,
>         .splice_write           = iter_file_splice_write,
>         .llseek                 = generic_file_llseek,
> +       .integrity_read         = generic_file_read_iter,
>  };
>
>  const struct inode_operations ramfs_file_inode_operations = {
> diff --git a/fs/ubifs/file.c b/fs/ubifs/file.c
> index 8cad0b19b404..5e52a315e18b 100644
> --- a/fs/ubifs/file.c
> +++ b/fs/ubifs/file.c
> @@ -1747,4 +1747,5 @@ const struct file_operations ubifs_file_operations = {
>  #ifdef CONFIG_COMPAT
>         .compat_ioctl   = ubifs_compat_ioctl,
>  #endif
> +       .integrity_read = generic_file_read_iter,
>  };
> diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
> index c4893e226fd8..0a6704b563d6 100644
> --- a/fs/xfs/xfs_file.c
> +++ b/fs/xfs/xfs_file.c
> @@ -292,6 +292,26 @@ xfs_file_read_iter(
>         return ret;
>  }
>
> +static ssize_t
> +xfs_integrity_read(
> +       struct kiocb            *iocb,
> +       struct iov_iter         *to)
> +{
> +       struct inode            *inode = file_inode(iocb->ki_filp);
> +       struct xfs_mount        *mp = XFS_I(inode)->i_mount;
> +
> +       lockdep_assert_held(&inode->i_rwsem);
> +
> +       XFS_STATS_INC(mp, xs_read_calls);
> +
> +       if (XFS_FORCED_SHUTDOWN(mp))
> +               return -EIO;
> +
> +       if (IS_DAX(inode))
> +               return dax_iomap_rw(iocb, to, &xfs_iomap_ops);
> +       return generic_file_read_iter(iocb, to);
> +}
> +
>  /*
>   * Zero any on disk space between the current EOF and the new, larger EOF.
>   *
> @@ -1175,6 +1195,7 @@ const struct file_operations xfs_file_operations = {
>         .fallocate      = xfs_file_fallocate,
>         .clone_file_range = xfs_file_clone_range,
>         .dedupe_file_range = xfs_file_dedupe_range,
> +       .integrity_read = xfs_integrity_read,
>  };
>
>  const struct file_operations xfs_dir_file_operations = {
> diff --git a/include/linux/fs.h b/include/linux/fs.h
> index fdec9b763b54..8d0d10e1dd93 100644
> --- a/include/linux/fs.h
> +++ b/include/linux/fs.h
> @@ -1699,6 +1699,7 @@ struct file_operations {
>                         u64);
>         ssize_t (*dedupe_file_range)(struct file *, u64, u64, struct file *,
>                         u64);
> +       ssize_t (*integrity_read)(struct kiocb *, struct iov_iter *);
>  } __randomize_layout;
>
>  struct inode_operations {
> diff --git a/mm/shmem.c b/mm/shmem.c
> index b0aa6075d164..805d99011ca4 100644
> --- a/mm/shmem.c
> +++ b/mm/shmem.c
> @@ -3849,6 +3849,7 @@ static const struct file_operations shmem_file_operations = {
>         .splice_read    = generic_file_splice_read,
>         .splice_write   = iter_file_splice_write,
>         .fallocate      = shmem_fallocate,
> +       .integrity_read = shmem_file_read_iter,
>  #endif
>  };
>
> diff --git a/security/integrity/iint.c b/security/integrity/iint.c
> index 6fc888ca468e..df04f35a1d40 100644
> --- a/security/integrity/iint.c
> +++ b/security/integrity/iint.c
> @@ -21,6 +21,7 @@
>  #include <linux/rbtree.h>
>  #include <linux/file.h>
>  #include <linux/uaccess.h>
> +#include <linux/uio.h>
>  #include "integrity.h"
>
>  static struct rb_root integrity_iint_tree = RB_ROOT;
> @@ -184,18 +185,25 @@ security_initcall(integrity_iintcache_init);
>  int integrity_kernel_read(struct file *file, loff_t offset,
>                           void *addr, unsigned long count)
>  {
> -       mm_segment_t old_fs;
> -       char __user *buf = (char __user *)addr;
> +       struct inode *inode = file_inode(file);
> +       struct kvec iov = { .iov_base = addr, .iov_len = count };
> +       struct kiocb kiocb;
> +       struct iov_iter iter;
>         ssize_t ret;
>
> +       lockdep_assert_held(&inode->i_rwsem);
> +
>         if (!(file->f_mode & FMODE_READ))
>                 return -EBADF;
> +       if (!file->f_op->integrity_read)
> +               return -EBADF;
>
> -       old_fs = get_fs();
> -       set_fs(get_ds());
> -       ret = __vfs_read(file, buf, count, &offset);
> -       set_fs(old_fs);
> +       init_sync_kiocb(&kiocb, file);
> +       kiocb.ki_pos = offset;
> +       iov_iter_kvec(&iter, READ | ITER_KVEC, &iov, 1, count);
>
> +       ret = file->f_op->integrity_read(&kiocb, &iter);
> +       BUG_ON(ret == -EIOCBQUEUED);
>         return ret;
>  }
>
> --
> 2.7.4
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-security-module" in
> the body of a message to majordomo at vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html



-- 
Thanks,
Dmitry
--
To unsubscribe from this list: send the line "unsubscribe linux-security-module" in
the body of a message to majordomo at vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html



More information about the Linux-security-module-archive mailing list