[PATCH v5 2/4] ima: use fs method to read integrity data
Mimi Zohar
zohar at linux.vnet.ibm.com
Thu Aug 10 23:41:45 UTC 2017
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.
Signed-off-by: Christoph Hellwig <hch at lst.de>
Cc: Matthew Garrett <matthew.garrett at nebula.com>
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 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 | 12 +++++++-----
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/libfs.c | 32 ++++++++++++++++++++++++++++++++
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 | 3 +++
mm/shmem.c | 1 +
security/integrity/iint.c | 20 ++++++++++++++------
16 files changed, 123 insertions(+), 11 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 5f22e74bbade..17955a92a5b3 100644
--- a/fs/efivarfs/file.c
+++ b/fs/efivarfs/file.c
@@ -64,9 +64,10 @@ static ssize_t efivarfs_file_write(struct file *file,
return bytes;
}
-static ssize_t efivarfs_file_read(struct file *file, char __user *userbuf,
- size_t count, loff_t *ppos)
+static ssize_t efivarfs_file_read_iter(struct kiocb *iocb,
+ struct iov_iter *iter)
{
+ struct file *file = iocb->ki_filp;
struct efivar_entry *var = file->private_data;
unsigned long datasize = 0;
u32 attributes;
@@ -96,8 +97,8 @@ static ssize_t efivarfs_file_read(struct file *file, char __user *userbuf,
goto out_free;
memcpy(data, &attributes, sizeof(attributes));
- size = simple_read_from_buffer(userbuf, count, ppos,
- data, datasize + sizeof(attributes));
+ size = simple_read_iter_from_buffer(iocb, iter, data,
+ datasize + sizeof(attributes));
out_free:
kfree(data);
@@ -174,8 +175,9 @@ efivarfs_file_ioctl(struct file *file, unsigned int cmd, unsigned long p)
const struct file_operations efivarfs_file_operations = {
.open = simple_open,
- .read = efivarfs_file_read,
+ .read_iter = efivarfs_file_read_iter,
.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/libfs.c b/fs/libfs.c
index 3aabe553fc45..b6e304c6828b 100644
--- a/fs/libfs.c
+++ b/fs/libfs.c
@@ -16,6 +16,7 @@
#include <linux/exportfs.h>
#include <linux/writeback.h>
#include <linux/buffer_head.h> /* sync_mapping_buffers */
+#include <linux/uio.h>
#include <linux/uaccess.h>
@@ -676,6 +677,37 @@ ssize_t simple_write_to_buffer(void *to, size_t available, loff_t *ppos,
EXPORT_SYMBOL(simple_write_to_buffer);
/**
+ * simple_read_iter_from_buffer - copy data from the buffer to user space
+ * @iocb: struct containing the file, the current position and other info
+ * @to: the user space buffer to read to
+ * @from: the buffer to read from
+ * @available: the size of the buffer
+ *
+ * The simple_read_iter_from_buffer() function reads up to @available bytes
+ * from the current buffer into the user space buffer.
+ *
+ * On success, the current buffer offset is advanced by the number of bytes
+ * read, or a negative value is returned on error.
+ **/
+ssize_t simple_read_iter_from_buffer(struct kiocb *iocb, struct iov_iter *to,
+ const void *from, size_t available)
+{
+ loff_t pos = iocb->ki_pos;
+ size_t ret;
+
+ if (pos < 0)
+ return -EINVAL;
+ if (pos >= available)
+ return 0;
+ ret = copy_to_iter(from + pos, available - pos, to);
+ if (!ret && iov_iter_count(to))
+ return -EFAULT;
+ iocb->ki_pos = pos + ret;
+ return ret;
+}
+EXPORT_SYMBOL(simple_read_iter_from_buffer);
+
+/**
* memory_read_from_buffer - copy data from the buffer
* @to: the kernel space buffer to read to
* @count: the maximum number of bytes to read
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 6e1fd5d21248..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 {
@@ -3097,6 +3098,8 @@ extern void simple_release_fs(struct vfsmount **mount, int *count);
extern ssize_t simple_read_from_buffer(void __user *to, size_t count,
loff_t *ppos, const void *from, size_t available);
+extern ssize_t simple_read_iter_from_buffer(struct kiocb *iocb,
+ struct iov_iter *to, const void *from, size_t available);
extern ssize_t simple_write_to_buffer(void *to, size_t available, loff_t *ppos,
const void __user *from, size_t count);
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
--
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