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. Also the presence of ->integrity_read indicates
that the file system can support IMA.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
fs/btrfs/file.c | 1 +
fs/ext4/file.c | 1 +
fs/xfs/xfs_file.c | 21 +++++++++++++++++++++
include/linux/fs.h | 1 +
security/integrity/iint.c | 20 ++++++++++++++------
5 files changed, 38 insertions(+), 6 deletions(-)
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 520cb7230b2d..c5afb2264737 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -3041,6 +3041,7 @@ 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/ext4/file.c b/fs/ext4/file.c
index 8210c1f43556..b2a5025c7e0d 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -740,6 +740,7 @@ 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_read_iter,
};
const struct inode_operations ext4_file_inode_operations = {
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 35703a801372..3d6ace2a79bc 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -288,6 +288,26 @@ 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.
*
@@ -1534,6 +1554,7 @@ 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 7251f7bb45e8..0c86816ca25f 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1689,6 +1689,7 @@ 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 *);
};
struct inode_operations {
diff --git a/security/integrity/iint.c b/security/integrity/iint.c
index c710d22042f9..c5489672b5aa 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,
char *addr, unsigned long count)
{
- mm_segment_t old_fs;
- char __user *buf = (char __user *)addr;
+ struct inode *inode = file_inode(file);
+ struct iovec 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_init(&iter, READ | ITER_KVEC, &iov, 1, count);
+ ret = file->f_op->integrity_read(&kiocb, &iter);
+ BUG_ON(ret == -EIOCBQUEUED);
return ret;
}
