[PATCH 6.18 183/314] xfs: Fix error pointer dereference

Sasha Levin
2026-03-10T11:27:37Z

From: Ethan Tidmore <ethantidmore06@gmail.com>

commit cddfa648f1ab99e30e91455be19cd5ade26338c2 upstream.

The function try_lookup_noperm() can return an error pointer and is not
checked for one.

Add checks for error pointer in xrep_adoption_check_dcache() and
xrep_adoption_zap_dcache().

Detected by Smatch:
fs/xfs/scrub/orphanage.c:449 xrep_adoption_check_dcache() error:
'd_child' dereferencing possible ERR_PTR()

fs/xfs/scrub/orphanage.c:485 xrep_adoption_zap_dcache() error:
'd_child' dereferencing possible ERR_PTR()

Fixes: 73597e3e42b4 ("xfs: ensure dentry consistency when the orphanage adopts a file")
Cc: stable@vger.kernel.org # v6.16
Signed-off-by: Ethan Tidmore <ethantidmore06@gmail.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Nirjhar Roy (IBM) <nirjhar.roy.lists@gmail.com>
Signed-off-by: Carlos Maiolino <cem@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/xfs/scrub/orphanage.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/fs/xfs/scrub/orphanage.c b/fs/xfs/scrub/orphanage.c
index 9c12cb8442311..3c4f3b542c20f 100644
--- a/fs/xfs/scrub/orphanage.c
+++ b/fs/xfs/scrub/orphanage.c
@@ -445,6 +445,11 @@ xrep_adoption_check_dcache(
return 0;

d_child = try_lookup_noperm(&qname, d_orphanage);
+ if (IS_ERR(d_child)) {
+ dput(d_orphanage);
+ return PTR_ERR(d_child);
+ }
+
if (d_child) {
trace_xrep_adoption_check_child(sc->mp, d_child);

@@ -482,7 +487,7 @@ xrep_adoption_zap_dcache(
return;

d_child = try_lookup_noperm(&qname, d_orphanage);
- while (d_child != NULL) {
+ while (!IS_ERR_OR_NULL(d_child)) {
trace_xrep_adoption_invalidate_child(sc->mp, d_child);

ASSERT(d_is_negative(d_child));
--
2.51.0