[PATCH] Add security_file_permission() to AIO paths.

Currently, there are no LSM hooks in the AIO codepaths, which means that
LSM based access controls are not revalidated upon AIO read and write
operations.  The patch below adds the security_file_permission() LSM hook
prior to the VFS aio_read()/aio_write() calls.
Signed-off-by: James Morris <jmorris@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

fs/aio.c

@@ -27,6 +27,7 @@
 #include <linux/aio.h>
 #include <linux/highmem.h>
 #include <linux/workqueue.h>
+#include <linux/security.h>
 
 #include <asm/kmap_types.h>
 #include <asm/uaccess.h>
@@ -1036,6 +1037,9 @@ int fastcall io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb,
 		ret = -EFAULT;
 		if (unlikely(!access_ok(VERIFY_WRITE, buf, iocb->aio_nbytes)))
 			goto out_put_req;
+		ret = security_file_permission (file, MAY_READ);
+		if (ret)
+			goto out_put_req;
 		ret = -EINVAL;
 		if (file->f_op->aio_read)
 			ret = file->f_op->aio_read(req, buf,
@@ -1048,6 +1052,9 @@ int fastcall io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb,
 		ret = -EFAULT;
 		if (unlikely(!access_ok(VERIFY_READ, buf, iocb->aio_nbytes)))
 			goto out_put_req;
+		ret = security_file_permission (file, MAY_WRITE);
+		if (ret)
+			goto out_put_req;
 		ret = -EINVAL;
 		if (file->f_op->aio_write)
 			ret = file->f_op->aio_write(req, buf,