From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753231AbbBQTbG (ORCPT ); Tue, 17 Feb 2015 14:31:06 -0500 Received: from zeniv.linux.org.uk ([195.92.253.2]:50115 "EHLO ZenIV.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752753AbbBQTbE (ORCPT ); Tue, 17 Feb 2015 14:31:04 -0500 Date: Tue, 17 Feb 2015 19:31:01 +0000 From: Al Viro To: Sudip Mukherjee Cc: Andrew Morton , linux-kernel@vger.kernel.org Subject: Re: [PATCH 4/5] fs: efs: fix possible memory leak Message-ID: <20150217193101.GA11847@ZenIV.linux.org.uk> References: <1423731742-31383-1-git-send-email-sudipm.mukherjee@gmail.com> <1423731742-31383-4-git-send-email-sudipm.mukherjee@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1423731742-31383-4-git-send-email-sudipm.mukherjee@gmail.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Feb 12, 2015 at 02:32:21PM +0530, Sudip Mukherjee wrote: > we are allocating memory for struct efs_sb_info, but afterwards when > we are returning with error we are not releasing the memory. The hell we are not - unlike ->put_super(), ->kill_sb() is *always* called, even when fill_super() fails halfway through. Exactly because it makes for simpler cleanup requirements on failure exits in said fill_super(). And we have static void efs_kill_sb(struct super_block *s) { struct efs_sb_info *sbi = SUPER_INFO(s); kill_block_super(s); kfree(sbi); } for ->kill_sb() there, so sbi will *not* leak. NAK. This patch not only complicates efs_fill_super() for no good reason, it ends up with double kfree() on those failure exits - ->s_fs_info is left pointing to freed memory and efs_kill_sb() does kfree() again.