[PATCH 8/8] xfs: fix bounds check in xfs_defer_agfl_block()

Dave Chinner
2023-06-27T22:44:30Z

From: Dave Chinner <dchinner@redhat.com>

Need to happen before we allocate and then leak the xefi. Found by
coverity via an xfsprogs libxfs scan.

Fixes: 7dfee17b13e5 ("xfs: validate block number being freed before adding to xefi")
Signed-off-by: Dave Chinner <dchinner@redhat.com>
---
fs/xfs/libxfs/xfs_alloc.c | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/fs/xfs/libxfs/xfs_alloc.c b/fs/xfs/libxfs/xfs_alloc.c
index 7c86a69354fb..9919fdfe1d7e 100644
--- a/fs/xfs/libxfs/xfs_alloc.c
+++ b/fs/xfs/libxfs/xfs_alloc.c
@@ -2470,25 +2470,26 @@ static int
xfs_defer_agfl_block(
struct xfs_trans *tp,
xfs_agnumber_t agno,
- xfs_fsblock_t agbno,
+ xfs_agblock_t agbno,
struct xfs_owner_info *oinfo)
{
struct xfs_mount *mp = tp->t_mountp;
struct xfs_extent_free_item *xefi;
+ xfs_fsblock_t fsbno = XFS_AGB_TO_FSB(mp, agno, agbno);

ASSERT(xfs_extfree_item_cache != NULL);
ASSERT(oinfo != NULL);

+ if (XFS_IS_CORRUPT(mp, !xfs_verify_fsbno(mp, fsbno)))
+ return -EFSCORRUPTED;
+
xefi = kmem_cache_zalloc(xfs_extfree_item_cache,
GFP_KERNEL | __GFP_NOFAIL);
- xefi->xefi_startblock = XFS_AGB_TO_FSB(mp, agno, agbno);
+ xefi->xefi_startblock = fsbno;
xefi->xefi_blockcount = 1;
xefi->xefi_owner = oinfo->oi_owner;
xefi->xefi_type = XFS_AG_RESV_AGFL;

- if (XFS_IS_CORRUPT(mp, !xfs_verify_fsbno(mp, xefi->xefi_startblock)))
- return -EFSCORRUPTED;
-
trace_xfs_agfl_free_defer(mp, agno, 0, agbno, 1);

xfs_extent_free_get_group(mp, xefi);
--
2.40.1