vfs: make AIO use the proper rw_verify_area() area helpers
We had for some reason overlooked the AIO interface, and it didn't use
the proper rw_verify_area() helper function that checks (for example)
mandatory locking on the file, and that the size of the access doesn't
cause us to overflow the provided offset limits etc.
Instead, AIO did just the security_file_permission() thing (that
rw_verify_area() also does) directly.
This fixes it to do all the proper helper functions, which not only
means that now mandatory file locking works with AIO too, we can
actually remove lines of code.
Reported-by: Manish Honap <manish_honap_vit@yahoo.co.in>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/aio.c b/fs/aio.c
index 67a6db3..e7f2fad 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -1456,6 +1456,10 @@
if (ret < 0)
goto out;
+ ret = rw_verify_area(type, kiocb->ki_filp, &kiocb->ki_pos, ret);
+ if (ret < 0)
+ goto out;
+
kiocb->ki_nr_segs = kiocb->ki_nbytes;
kiocb->ki_cur_seg = 0;
/* ki_nbytes/left now reflect bytes instead of segs */
@@ -1467,11 +1471,17 @@
return ret;
}
-static ssize_t aio_setup_single_vector(struct kiocb *kiocb)
+static ssize_t aio_setup_single_vector(int type, struct file * file, struct kiocb *kiocb)
{
+ int bytes;
+
+ bytes = rw_verify_area(type, file, &kiocb->ki_pos, kiocb->ki_left);
+ if (bytes < 0)
+ return bytes;
+
kiocb->ki_iovec = &kiocb->ki_inline_vec;
kiocb->ki_iovec->iov_base = kiocb->ki_buf;
- kiocb->ki_iovec->iov_len = kiocb->ki_left;
+ kiocb->ki_iovec->iov_len = bytes;
kiocb->ki_nr_segs = 1;
kiocb->ki_cur_seg = 0;
return 0;
@@ -1496,10 +1506,7 @@
if (unlikely(!access_ok(VERIFY_WRITE, kiocb->ki_buf,
kiocb->ki_left)))
break;
- ret = security_file_permission(file, MAY_READ);
- if (unlikely(ret))
- break;
- ret = aio_setup_single_vector(kiocb);
+ ret = aio_setup_single_vector(READ, file, kiocb);
if (ret)
break;
ret = -EINVAL;
@@ -1514,10 +1521,7 @@
if (unlikely(!access_ok(VERIFY_READ, kiocb->ki_buf,
kiocb->ki_left)))
break;
- ret = security_file_permission(file, MAY_WRITE);
- if (unlikely(ret))
- break;
- ret = aio_setup_single_vector(kiocb);
+ ret = aio_setup_single_vector(WRITE, file, kiocb);
if (ret)
break;
ret = -EINVAL;
@@ -1528,9 +1532,6 @@
ret = -EBADF;
if (unlikely(!(file->f_mode & FMODE_READ)))
break;
- ret = security_file_permission(file, MAY_READ);
- if (unlikely(ret))
- break;
ret = aio_setup_vectored_rw(READ, kiocb, compat);
if (ret)
break;
@@ -1542,9 +1543,6 @@
ret = -EBADF;
if (unlikely(!(file->f_mode & FMODE_WRITE)))
break;
- ret = security_file_permission(file, MAY_WRITE);
- if (unlikely(ret))
- break;
ret = aio_setup_vectored_rw(WRITE, kiocb, compat);
if (ret)
break;