linux-ext4 - e2fsck can't handle bad extents w/ bad bitmaps

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>] [day] [month] [year] [list]

Message-ID: <52A77BF5.5060204@ddn.com>
Date:	Tue, 10 Dec 2013 15:39:17 -0500
From:	Kit Westneat <kwestneat@....com>
To:	"linux-ext4@...r.kernel.org" <linux-ext4@...r.kernel.org>
Subject: e2fsck can't handle bad extents w/ bad bitmaps

Hello,

We ran into an issue recently where we had a filesystem that had both 
invalid bitmaps and corrupted extent nodes. The issue was that currently 
the fix for a corrupted extent requires that the bitmaps be read in:
pass1.c +2250, scan_extent_node:
             pctx->blk = extent.e_pblk;
             pctx->blk2 = extent.e_lblk;
             pctx->num = extent.e_len;
             if (fix_problem(ctx, problem, pctx)) {
 >>              e2fsck_read_bitmaps(ctx);
                 pctx->errcode =
                     ext2fs_extent_delete(ehandle, 0);

Which then fails:
e2fsck/util.c +272, e2fsck_read_bitmaps:
     if (ctx->invalid_bitmaps) {
         com_err(ctx->program_name, 0,
             _("e2fsck_read_bitmaps: illegal bitmap block(s) for %s"),

We just ended up adding a patch to ignore the bad extents, but I just 
wanted to let people know that this problem exists.

Thanks,
Kit

-- 
---
Kit Westneat
L3 Lustre Support, DDN
703-659-3869

--
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