Commit b828d8c3 authored Jan 19, 2009 by Christoph Hellwig Committed by Lachlan McIlroy Jan 19, 2009

xfs: sanity check attr fork size



Recently we have quite a few kerneloops reports about dereferencing a NULL
if_data in the attribute fork.  From looking over the code this can only
happen if we pass a 0 size argument to xfs_iformat_local.  This implies some
sort of corruption and in fact the only mailinglist report about this from
earlier this year was after a powerfail presumably on a system with write
cache and without barriers.

Add a quick sanity check for the attr fork size in xfs_iformat to catch
these early and without an oops.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <david@fromorbit.com>

parent 49739140

fs/xfs/xfs_inode.c

+13 −0

Original line number	Diff line number	Diff line
		@@ -424,6 +424,19 @@ xfs_iformat(
		case XFS_DINODE_FMT_LOCAL:
		atp = (xfs_attr_shortform_t *)XFS_DFORK_APTR(dip);
		size = be16_to_cpu(atp->hdr.totsize);

		if (unlikely(size < sizeof(struct xfs_attr_sf_hdr))) {
		xfs_fs_repair_cmn_err(CE_WARN, ip->i_mount,
		"corrupt inode %Lu "
		"(bad attr fork size %Ld).",
		(unsigned long long) ip->i_ino,
		(long long) size);
		XFS_CORRUPTION_ERROR("xfs_iformat(8)",
		XFS_ERRLEVEL_LOW,
		ip->i_mount, dip);
		return XFS_ERROR(EFSCORRUPTED);
		}

		error = xfs_iformat_local(ip, dip, XFS_ATTR_FORK, size);
		break;
		case XFS_DINODE_FMT_EXTENTS: