From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:47262 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751790AbeBTLLz (ORCPT ); Tue, 20 Feb 2018 06:11:55 -0500 Subject: Patch "seq_file: fix incomplete reset on read from zero offset" has been added to the 4.15-stable tree To: mszeredi@redhat.com, dalias@libc.org, gregkh@linuxfoundation.org, stable@vger.kernel.org, viro@zeniv.linux.org.uk Cc: , From: Date: Tue, 20 Feb 2018 12:10:32 +0100 Message-ID: <151912503214976@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled seq_file: fix incomplete reset on read from zero offset to the 4.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: seq_file-fix-incomplete-reset-on-read-from-zero-offset.patch and it can be found in the queue-4.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From cf5eebae2cd28d37581507668605f4d23cd7218d Mon Sep 17 00:00:00 2001 From: Miklos Szeredi Date: Wed, 15 Nov 2017 11:34:58 +0100 Subject: seq_file: fix incomplete reset on read from zero offset From: Miklos Szeredi commit cf5eebae2cd28d37581507668605f4d23cd7218d upstream. When resetting iterator on a zero offset we need to discard any data already in the buffer (count), and private state of the iterator (version). For example this bug results in first line being repeated in /proc/mounts if doing a zero size read before a non-zero size read. Reported-by: Rich Felker Signed-off-by: Miklos Szeredi Fixes: e522751d605d ("seq_file: reset iterator to first record for zero offset") Cc: # v4.10 Signed-off-by: Al Viro Signed-off-by: Greg Kroah-Hartman --- fs/seq_file.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) --- a/fs/seq_file.c +++ b/fs/seq_file.c @@ -181,8 +181,11 @@ ssize_t seq_read(struct file *file, char * if request is to read from zero offset, reset iterator to first * record as it might have been already advanced by previous requests */ - if (*ppos == 0) + if (*ppos == 0) { m->index = 0; + m->version = 0; + m->count = 0; + } /* Don't assume *ppos is where we left it */ if (unlikely(*ppos != m->read_pos)) { Patches currently in stable-queue which might be from mszeredi@redhat.com are queue-4.15/seq_file-fix-incomplete-reset-on-read-from-zero-offset.patch