Patchwork [3.5.y.z,extended,stable] Patch "vfs: fix pipe counter breakage" has been added to staging queue

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Submitter Luis Henriques
Date March 13, 2013, 1:07 p.m.
Message ID <1363180071-3768-1-git-send-email-luis.henriques@canonical.com>
Download mbox | patch
Permalink /patch/227282/
State New
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Luis Henriques - March 13, 2013, 1:07 p.m.
This is a note to let you know that I have just added a patch titled

    vfs: fix pipe counter breakage

to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.5.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

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From b041c2b62b02d59ef0b7f5dc04c54a9383e00c16 Mon Sep 17 00:00:00 2001
From: Al Viro <viro@ZenIV.linux.org.uk>
Date: Tue, 12 Mar 2013 02:59:49 +0000
Subject: [PATCH] vfs: fix pipe counter breakage

commit a930d8790552658140d7d0d2e316af4f0d76a512 upstream.

If you open a pipe for neither read nor write, the pipe code will not
add any usage counters to the pipe, causing the 'struct pipe_inode_info"
to be potentially released early.

That doesn't normally matter, since you cannot actually use the pipe,
but the pipe release code - particularly fasync handling - still expects
the actual pipe infrastructure to all be there.  And rather than adding
NULL pointer checks, let's just disallow this case, the same way we
already do for the named pipe ("fifo") case.

This is ancient going back to pre-2.4 days, and until trinity, nobody
naver noticed.

Reported-by: Dave Jones <davej@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
---
 fs/pipe.c | 3 +++
 1 file changed, 3 insertions(+)

--
1.8.1.2

Patch

diff --git a/fs/pipe.c b/fs/pipe.c
index 49c1065..b342faa 100644
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -863,6 +863,9 @@  pipe_rdwr_open(struct inode *inode, struct file *filp)
 {
 	int ret = -ENOENT;

+	if (!(filp->f_mode & (FMODE_READ|FMODE_WRITE)))
+		return -EINVAL;
+
 	mutex_lock(&inode->i_mutex);

 	if (inode->i_pipe) {