From: jing zhang Subject: [PATCH] ext4: memory leakage in ext4_mb_free_blocks() Date: Wed, 24 Mar 2010 21:55:55 +0800 Message-ID: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Cc: "Theodore Ts'o" , Andreas Dilger , Dave Kleikamp To: linux-ext4 Return-path: Received: from mail-yx0-f188.google.com ([209.85.210.188]:63010 "EHLO mail-yx0-f188.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756314Ab0CXOCj (ORCPT ); Wed, 24 Mar 2010 10:02:39 -0400 Received: by yxe26 with SMTP id 26so2826649yxe.23 for ; Wed, 24 Mar 2010 07:02:38 -0700 (PDT) Sender: linux-ext4-owner@vger.kernel.org List-ID: From: Jing Zhang Date: Wed Mar 24 21:54:22 2010 There is memory leakage in ext4_mb_free_blocks(), if error, double free of blocks, occurs in ext4_mb_free_metadata(). Cc: Theodore Ts'o Cc: Andreas Dilger Cc: Dave Kleikamp Signed-off-by: Jing Zhang --- --- linux-2.6.32/fs/ext4/mballoc.c 2009-12-03 11:51:22.000000000 +0800 +++ ext4_mm_leak/mballoc8.c 2010-03-24 21:46:50.000000000 +0800 @@ -4419,7 +4419,8 @@ ext4_mb_free_metadata(handle_t *handle, spin_lock(&sbi->s_md_lock); list_add(&new_entry->list, &handle->h_transaction->t_private_list); spin_unlock(&sbi->s_md_lock); - return 0; + /* info the caller new_entry is used */ + return 1; } /* @@ -4547,7 +4548,8 @@ do_more: ext4_lock_group(sb, block_group); mb_clear_bits(bitmap_bh->b_data, bit, count); - ext4_mb_free_metadata(handle, &e4b, new_entry); + if (0 == ext4_mb_free_metadata(handle, &e4b, new_entry)) + kmem_cache_free(ext4_free_ext_cachep, new_entry); } else { /* need to update group_info->bb_free and bitmap * with group lock held. generate_buddy look at