xfs: fix uninitialized variable access

Commit Message

Darrick J. Wong Feb. 10, 2023, 5:13 p.m. UTC

From: Darrick J. Wong <[e-mail]>

If the end position of a GETFSMAP query overlaps an allocated space and
we're using the free space info to generate fsmap info, the akeys
information gets fed into the fsmap formatter with bad results.
Zero-init the space.

Reported-by: [e-mail]
Signed-off-by: Darrick J. Wong <[e-mail]>
---
 fs/xfs/xfs_fsmap.c |    1 +
 1 file changed, 1 insertion(+)

Patch

diff --git a/fs/xfs/xfs_fsmap.c b/fs/xfs/xfs_fsmap.c
index 88a88506ffff..92ca2017eded 100644
--- a/fs/xfs/xfs_fsmap.c
+++ b/fs/xfs/xfs_fsmap.c
@@ -761,6 +761,7 @@  xfs_getfsmap_datadev_bnobt(
 {
 	struct xfs_alloc_rec_incore	akeys[2];
 
+	memset(akeys, 0, sizeof(akeys));
 	info->missing_owner = XFS_FMR_OWN_UNKNOWN;
 	return __xfs_getfsmap_datadev(tp, keys, info,
 			xfs_getfsmap_datadev_bnobt_query, &akeys[0]);