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vfs: make AIO use the proper rw_verify_area() area helpers

commit a70b52ec1aaeaf60f4739edb1b422827cb6f3893 upstream.

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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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torvalds authored and gregkh committed May 21, 2012
1 parent ee9d6e9 commit 2ec196c975ffb8076df77f6fa929448717e5141b
Showing with 14 additions and 16 deletions.
  1. +14 −16 fs/aio.c
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@@ -1395,6 +1395,10 @@ static ssize_t aio_setup_vectored_rw(int type, struct kiocb *kiocb, bool compat)
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 */
@@ -1406,11 +1410,17 @@ static ssize_t aio_setup_vectored_rw(int type, struct kiocb *kiocb, bool compat)
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;
@@ -1435,10 +1445,7 @@ static ssize_t aio_setup_iocb(struct kiocb *kiocb, bool compat)
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;
@@ -1453,10 +1460,7 @@ static ssize_t aio_setup_iocb(struct kiocb *kiocb, bool compat)
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;
@@ -1467,9 +1471,6 @@ static ssize_t aio_setup_iocb(struct kiocb *kiocb, bool compat)
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;
@@ -1481,9 +1482,6 @@ static ssize_t aio_setup_iocb(struct kiocb *kiocb, bool compat)
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;

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