smb: client: harden DFS cache against invalid target hints

Currently, get_tgt_name() returns ERR_PTR(-ENOENT) when ce->tgthint is
NULL, and dfs_cache_noreq_update_tgthint() assumes ce->tgthint is always
valid.

In preparation for clearing ce->tgthint in free_tgts(), harden callers
of get_tgt_name() against ERR_PTR results and harden
dfs_cache_noreq_update_tgthint() against NULL pointer dereferences.

Cc: stable@vger.kernel.org
Signed-off-by: Fredric Cover <fredric.cover.lkernel@gmail.com>
Reviewed-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Paulo Alcantara <pc@manguebit.org>
This commit is contained in:
Fredric Cover 2026-07-24 15:01:45 -07:00 • committed by Paulo Alcantara
commit bf86c08123