From: Theodore Tso Subject: Re: [PATCH] [e2fsprogs] e2fsck: fix segmentation fault when block size is greater than 8192 Date: Fri, 2 Jan 2009 18:30:46 -0500 Message-ID: <20090102233046.GF4758@mit.edu> References: <4948BF24.3040601@cn.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-ext4@vger.kernel.org To: Miao Xie Return-path: Received: from THUNK.ORG ([69.25.196.29]:56838 "EHLO thunker.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751573AbZABXay (ORCPT ); Fri, 2 Jan 2009 18:30:54 -0500 Content-Disposition: inline In-Reply-To: <4948BF24.3040601@cn.fujitsu.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Wed, Dec 17, 2008 at 04:58:12PM +0800, Miao Xie wrote: > When I did fsck a filesystem with large blocksize(greater than 8192), > segmentation fault occured. The cause is the size of b_data array that is > defined as a fixed size in buffer_head structure. Here's a better patch which avoids the need for two calls to malloc for each buffer_head strcture. - Ted commit e35d548b59e24af9f7fc18396e8880df96d1bc51 Author: Theodore Ts'o Date: Fri Jan 2 18:14:42 2009 -0500 e2fsck: Fix journal replay for block sizes greater than 8k E2fsck was using a fixed-size 8k buffer for replaying blocks from the journal. So attempts to replay a journal on filesystems greater than 8k would cause e2fsck to crash with a segfault. Thanks to Miao Xie for reporting this problem. Signed-off-by: "Theodore Ts'o" diff --git a/e2fsck/jfs_user.h b/e2fsck/jfs_user.h index 0e4f951..60cc682 100644 --- a/e2fsck/jfs_user.h +++ b/e2fsck/jfs_user.h @@ -15,7 +15,6 @@ #include "e2fsck.h" struct buffer_head { - char b_data[8192]; e2fsck_t b_ctx; io_channel b_io; int b_size; @@ -23,6 +22,7 @@ struct buffer_head { int b_dirty; int b_uptodate; int b_err; + char b_data[1024]; }; struct inode { diff --git a/e2fsck/journal.c b/e2fsck/journal.c index 10f5095..adbd3db 100644 --- a/e2fsck/journal.c +++ b/e2fsck/journal.c @@ -68,8 +68,10 @@ int journal_bmap(journal_t *journal, blk_t block, unsigned long *phys) struct buffer_head *getblk(kdev_t kdev, blk_t blocknr, int blocksize) { struct buffer_head *bh; + int bufsize = sizeof(*bh) + kdev->k_ctx->fs->blocksize - + sizeof(bh->b_data); - bh = e2fsck_allocate_memory(kdev->k_ctx, sizeof(*bh), "block buffer"); + bh = e2fsck_allocate_memory(kdev->k_ctx, bufsize, "block buffer"); if (!bh) return NULL;