The patch titled
pipe_rdwr_fasync: fix the error handling to prevent the leak/crash
has been added to the -mm tree. Its filename is
pipe_rdwr_fasync-fix-the-error-handling-to-prevent-the-leak-crash.patch
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------------------------------------------------------
Subject: pipe_rdwr_fasync: fix the error handling to prevent the leak/crash
From: Oleg Nesterov <oleg@xxxxxxxxxx>
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@xxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Andi Kleen <andi@xxxxxxxxxxxxxx>
Cc: Jonathan Corbet <corbet@xxxxxxx>
Cc: <stable@xxxxxxxxxx> [2.6.28.x]
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/pipe.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff -puN fs/pipe.c~pipe_rdwr_fasync-fix-the-error-handling-to-prevent-the-leak-crash fs/pipe.c
--- a/fs/pipe.c~pipe_rdwr_fasync-fix-the-error-handling-to-prevent-the-leak-crash
+++ a/fs/pipe.c
@@ -699,12 +699,13 @@ pipe_rdwr_fasync(int fd, struct file *fi
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)
_
Patches currently in -mm which might be from oleg@xxxxxxxxxx are
linux-next.patch
pipe_rdwr_fasync-fix-the-error-handling-to-prevent-the-leak-crash.patch
getrusage-fill-ru_maxrss-value.patch
pids-document-task_pgrp-task_session-is-not-safe-without-tasklist-rcu.patch
pids-document-task_pgrp-task_session-is-not-safe-without-tasklist-rcu-fix.patch
pids-improve-get_task_pid-to-fix-the-unsafe-sys_wait4-task_pgrp.patch
pids-refactor-vnr-nr_ns-helpers-to-make-them-safe.patch
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