From e5bc49ba7439b9726006d031d440cba96819f0f8 Mon Sep 17 00:00:00 2001
From: Oleg Nesterov <oleg@redhat.com>
Date: Thu, 12 Mar 2009 14:31:28 -0700
Subject: [PATCH] pipe_rdwr_fasync: fix the error handling to prevent the
leak/crash
If the second fasync_helper() fails, pipe_rdwr_fasync() returns the error
but leaves the file on ->fasync_readers.
This was always wrong, but since 233e70f4228e78eb2f80dc6650f65d3ae3dbf17c
"saner FASYNC handling on file close" we have the new problem. Because in
this case setfl() doesn't set FASYNC bit, __fput() will not do
->fasync(0), and we leak fasync_struct with ->fa_file pointing to the
freed file.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
fs/pipe.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/fs/pipe.c b/fs/pipe.c
index 3a48ba5179d550..14f502b89cf5c2 100644
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -699,12 +699,12 @@ pipe_rdwr_fasync(int fd, struct file *filp, int on)
int retval;
mutex_lock(&inode->i_mutex);
-
retval = fasync_helper(fd, filp, on, &pipe->fasync_readers);
-
- if (retval >= 0)
+ if (retval >= 0) {
retval = fasync_helper(fd, filp, on, &pipe->fasync_writers);
-
+ if (retval < 0) /* this can happen only if on == T */
+ fasync_helper(-1, filp, 0, &pipe->fasync_readers);
+ }
mutex_unlock(&inode->i_mutex);
if (retval < 0)
--
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