[PATCH v2 0/2] smb: client: fix dangling pointer in DFS target hints

From: Fredric Cover

Date: Fri Jul 24 2026 - 17:48:09 EST


This series addresses a Use-After-Free bug where ce->tgthint was left
pointing to freed memory after free_tgts() was called.

To fix this, Patch 1 hardens the DFS cache readers against ce->tgthint
being NULL. Also, Patch 1 hardens callers of get_tgt_name(), which
returns an error pointer when ce->tgthint is NULL.

Patch 2 clears ce->tgthint in free_tgts(), eliminating the dangling
pointer.

v1 -> v2:
- Addressed automated review by Sashiko:
https://sashiko.dev/#/patchset/20260724023539.1596955-1-fredric.cover.lkernel%40gmail.com
Split into a 2-patch series to harden readers against NULL and
ERR_PTR target hints so that clearing ce->tgthint does not cause
NULL pointer dereferences.

Fredric Cover (2):
smb: client: harden DFS cache against invalid target hints
smb: client: clear ce->tgthint in free_tgts()

fs/smb/client/dfs_cache.c | 33 ++++++++++++++++++++++++++-------
1 file changed, 26 insertions(+), 7 deletions(-)

--
2.53.0