linux-ext4 - e2fsck aborts when invalid indirect block is encountered

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <20110901063410.GA8313@notebook.chenhuan>
Date:	Thu, 1 Sep 2011 14:34:10 +0800
From:	Chen Huan <chenhuan@...hpc.ac.cn>
To:	linux-ext4@...r.kernel.org
Subject: e2fsck aborts when invalid indirect block is encountered

Hi, All.

During a recent read-only checking of an corrupted ext3 file system,
I found a strange behaviour of e2fsck: when an inode has an invalid
indirect block number, e2fsck aborts with the following message:

    e2fsck 1.39 (29-May-2006)
    Pass 1: Checking inodes, blocks, and sizes
    Inode 12 has illegal block(s).  Clear? no

    Illegal block #-1 (4294967295) in inode 12.  IGNORED.
    Error while iterating over blocks in inode 12: Illegal indirect block found
    e2fsck: aborted

You can reproduce it with this code snippet:

    #!/bin/sh

    dev=/dev/sde
    mnt=/mnt

    mkfs.ext3 -F $dev
    mount $dev $mnt
    dd if=/dev/zero of=$mnt/file bs=1M count=1
    umount $dev
    debugfs -w -R 'sif file block[IND] 0xFFFFFFFF' $dev
    e2fsck -f -n $dev

Doing a fixing without -n option can safely delete this bad blocknum.

My question is: Is this behaviour a bug or intended?
--
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html