Commit 28d7a6ae authored Aug 18, 2009 by Graff Yang Committed by Linus Torvalds Aug 18, 2009

nommu: check fd read permission in validate_mmap_request()



According to the POSIX (1003.1-2008), the file descriptor shall have been
opened with read permission, regardless of the protection options specified to
mmap().  The ltp test cases mmap06/07 need this.

Signed-off-by: Graff Yang <graff.yang@gmail.com>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Greg Ungerer <gerg@snapgear.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 19152975

mm/nommu.c

+4 −0

Original line number	Original line	Diff line number	Diff line
	@@ -919,6 +919,10 @@ static int validate_mmap_request(struct file *file,
	if (!file->f_op->read)		if (!file->f_op->read)
	capabilities &= ~BDI_CAP_MAP_COPY;		capabilities &= ~BDI_CAP_MAP_COPY;

			/* The file shall have been opened with read permission. */
			if (!(file->f_mode & FMODE_READ))
			return -EACCES;

	if (flags & MAP_SHARED) {		if (flags & MAP_SHARED) {
	/* do checks for writing, appending and locking */		/* do checks for writing, appending and locking */
	if ((prot & PROT_WRITE) &&		if ((prot & PROT_WRITE) &&