public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: <graff.yang@gmail.com>
To: dhowells@redhat.com, linux-kernel@vger.kernel.org
Cc: akpm@linux-foundation.org,
	uclinux-dist-devel@blackfin.uclinux.org,
	Graff Yang <graff.yang@gmail.com>
Subject: [PATCH] mm/nommu.c: check read permission in validate_mmap_request()
Date: Fri, 14 Aug 2009 11:19:21 +0800	[thread overview]
Message-ID: <1250219961-11681-1-git-send-email-graff.yang@gmail.com> (raw)

From: Graff Yang <graff.yang@gmail.com>

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

Signed-off-by: Graff Yang <graff.yang@gmail.com>
---
 mm/nommu.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/mm/nommu.c b/mm/nommu.c
index 53cab10..ac13b23 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -922,6 +922,10 @@ static int validate_mmap_request(struct file *file,
 		if (!file->f_op->read)
 			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) {
 			/* do checks for writing, appending and locking */
 			if ((prot & PROT_WRITE) &&
-- 
1.6.1


             reply	other threads:[~2009-08-14  3:20 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-08-14  3:19 graff.yang [this message]
2009-08-14  4:57 ` [PATCH] mm/nommu.c: check read permission in validate_mmap_request() Paul Mundt

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1250219961-11681-1-git-send-email-graff.yang@gmail.com \
    --to=graff.yang@gmail.com \
    --cc=akpm@linux-foundation.org \
    --cc=dhowells@redhat.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=uclinux-dist-devel@blackfin.uclinux.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox