From e5bc49ba7439b9726006d031d440cba96819f0f8 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov 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 Cc: Al Viro Cc: Andi Kleen Cc: Jonathan Corbet Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/pipe.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/fs/pipe.c b/fs/pipe.c index 3a48ba5179d5..14f502b89cf5 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)