From: Dave Chinner <david@fromorbit.com>
To: Christoph Hellwig <hch@infradead.org>
Cc: xfs@oss.sgi.com
Subject: Re: [PATCH] repair: validate acl count before reading it
Date: Wed, 16 Nov 2011 11:23:23 +1100 [thread overview]
Message-ID: <20111116002323.GW5534@dastard> (raw)
In-Reply-To: <20111115080714.GA24931@infradead.org>
On Tue, Nov 15, 2011 at 03:07:15AM -0500, Christoph Hellwig wrote:
> This prevents a segfault on a filesystem so badly corrupted by the RAID
> controller that it could be considered fuzzed.
>
> Signed-off-by: Christoph Hellwig <hch@lst.de>
>
> Index: xfsprogs-dev/repair/attr_repair.c
> ===================================================================
> --- xfsprogs-dev.orig/repair/attr_repair.c 2011-11-14 20:03:27.000000000 +0000
> +++ xfsprogs-dev/repair/attr_repair.c 2011-11-14 20:20:55.000000000 +0000
> @@ -931,8 +931,8 @@ process_longform_attr(
> }
>
>
> -static xfs_acl_t *
> -xfs_acl_from_disk(xfs_acl_disk_t *dacl)
> +static int
> +xfs_acl_from_disk(struct xfs_acl **aclp, struct xfs_acl_disk *dacl)
> {
> int count;
> xfs_acl_t *acl;
> @@ -940,10 +940,22 @@ xfs_acl_from_disk(xfs_acl_disk_t *dacl)
> xfs_acl_entry_disk_t *dace, *end;
>
> count = be32_to_cpu(dacl->acl_cnt);
> + if (count > XFS_ACL_MAX_ENTRIES) {
> + do_warn(_("to larget ACL, size %d"), count);
"Too many ACL entries, count %d\n"
> + *aclp = NULL;
> + return EINVAL;
> + }
> +
> +
> end = &dacl->acl_entry[0] + count;
> acl = malloc((int)((char *)end - (char *)dacl));
> - if (!acl)
> - return NULL;
> + if (!acl) {
> + do_warn(_("cannot malloc enough for ACL attribute\n"));
> + do_warn(_("SKIPPING this ACL\n"));
Should you put that same "Skipping" message for all the error cases?
FWIW, should that status be stored somewhere so that when repair
completes it can emit a warning saying something like:
WARNING: ACLs were not correctly validated. You need to ensure ACLs are
consistently and appropriately applied to your filesytem.
Regardless, that can be done as a separate patch.
Reviewed-by: Dave Chinner <dchinner@redhat.com>
--
Dave Chinner
david@fromorbit.com
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next prev parent reply other threads:[~2011-11-16 0:23 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-11-15 8:07 [PATCH] repair: validate acl count before reading it Christoph Hellwig
2011-11-16 0:23 ` Dave Chinner [this message]
2011-11-16 7:58 ` Christoph Hellwig
2012-01-27 19:54 ` Mark Tinguely
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