Explicitly initialize the onstack structures to zero so we don't leak
kernel memory into userspace when converting the in-core inumbers
structure to the v1 inogrp ioctl structure. Add a comment about why we
have to use memset to ensure that the padding holes in the structures
are set to zero.
Fixes: 5f19c7fc6873351 ("xfs: introduce v5 inode group structure")
Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
---
v2: add comments, use memset this time
---
fs/xfs/xfs_itable.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/fs/xfs/xfs_itable.c b/fs/xfs/xfs_itable.c
index 30fe17d25518..39374c680c49 100644
--- a/fs/xfs/xfs_itable.c
+++ b/fs/xfs/xfs_itable.c
@@ -283,6 +283,7 @@ xfs_bulkstat_to_bstat(
struct xfs_bstat *bs1,
const struct xfs_bulkstat *bstat)
{
+ /* memset is needed here because of padding holes in the structure. */
memset(bs1, 0, sizeof(struct xfs_bstat));
bs1->bs_ino = bstat->bs_ino;
bs1->bs_mode = bstat->bs_mode;
@@ -399,6 +400,8 @@ xfs_inumbers_to_inogrp(
struct xfs_inogrp *ig1,
const struct xfs_inumbers *ig)
{
+ /* memset is needed here because of padding holes in the structure. */
+ memset(ig1, 0, sizeof(struct xfs_inogrp));
ig1->xi_startino = ig->xi_startino;
ig1->xi_alloccount = ig->xi_alloccount;
ig1->xi_allocmask = ig->xi_allocmask;
