From bbeae12fda3384a90fbebc8a19ba9d33f85b5361 Mon Sep 17 00:00:00 2001 From: Zhao Zhang Date: Fri, 19 Jun 2026 15:40:03 +0800 Subject: [PATCH] libceph: guard missing CRUSH type name lookup Localized read selection can walk a parent bucket whose name exists in the CRUSH map while its type has no matching entry in type_names. get_immediate_parent() then dereferences a NULL type_cn and passes an invalid pointer into strcmp(), causing a null-ptr-deref. Skip such malformed parent buckets unless both the bucket name and type name metadata are present. This keeps malformed hierarchy data from crashing locality lookup and safely falls back to "not local". [ idryomov: add WARN_ON_ONCE ] Cc: stable@vger.kernel.org Fixes: 117d96a04f00 ("libceph: support for balanced and localized reads") Reported-by: Yuan Tan Reported-by: Zhengchuan Liang Reported-by: Xin Liu Assisted-by: Codex:GPT-5.4 Signed-off-by: Zhao Zhang Signed-off-by: Ren Wei Reviewed-by: Viacheslav Dubeyko Signed-off-by: Ilya Dryomov --- net/ceph/osdmap.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/net/ceph/osdmap.c b/net/ceph/osdmap.c index 3c87f4b24e51..04036c047b8c 100644 --- a/net/ceph/osdmap.c +++ b/net/ceph/osdmap.c @@ -3060,8 +3060,11 @@ static int get_immediate_parent(struct crush_map *c, int id, if (b->items[j] != id) continue; - *parent_type_id = b->type; type_cn = lookup_crush_name(&c->type_names, b->type); + if (WARN_ON_ONCE(!type_cn)) + continue; + + *parent_type_id = b->type; parent_loc->cl_type_name = type_cn->cn_name; parent_loc->cl_name = cn->cn_name; return b->id;