diff options
| author | Christian Brauner <brauner@kernel.org> | 2025-11-09 22:11:27 +0100 |
|---|---|---|
| committer | Christian Brauner <brauner@kernel.org> | 2025-11-10 10:20:54 +0100 |
| commit | 57b39aabb99ea69b9046df2915404a931d9d6695 (patch) | |
| tree | 5f27368509ad3711ffcbef1ba7a309a3d6d481b7 | |
| parent | f8d5a8970d2f49411824fb1fdd34bbb3eea22756 (diff) | |
ns: add asserts for active refcount underflow
Add a few more assert to detect active reference count underflows.
Link: https://patch.msgid.link/20251109-namespace-6-19-fixes-v1-6-ae8a4ad5a3b3@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
| -rw-r--r-- | include/linux/ns_common.h | 1 | ||||
| -rw-r--r-- | kernel/nscommon.c | 18 |
2 files changed, 14 insertions, 5 deletions
diff --git a/include/linux/ns_common.h b/include/linux/ns_common.h index 3aaba2ca31d7..66ea09b48377 100644 --- a/include/linux/ns_common.h +++ b/include/linux/ns_common.h @@ -294,7 +294,6 @@ void __ns_ref_active_put(struct ns_common *ns); static __always_inline struct ns_common *__must_check ns_get_unless_inactive(struct ns_common *ns) { - VFS_WARN_ON_ONCE(__ns_ref_active_read(ns) && !__ns_ref_read(ns)); if (!__ns_ref_active_read(ns)) { VFS_WARN_ON_ONCE(is_ns_init_id(ns)); return NULL; diff --git a/kernel/nscommon.c b/kernel/nscommon.c index bfd2d6805776..c910b979e433 100644 --- a/kernel/nscommon.c +++ b/kernel/nscommon.c @@ -170,8 +170,10 @@ void __ns_ref_active_put(struct ns_common *ns) if (is_ns_init_id(ns)) return; - if (!atomic_dec_and_test(&ns->__ns_ref_active)) + if (!atomic_dec_and_test(&ns->__ns_ref_active)) { + VFS_WARN_ON_ONCE(__ns_ref_active_read(ns) < 0); return; + } VFS_WARN_ON_ONCE(is_ns_init_id(ns)); VFS_WARN_ON_ONCE(!__ns_ref_read(ns)); @@ -181,8 +183,10 @@ void __ns_ref_active_put(struct ns_common *ns) if (!ns) return; VFS_WARN_ON_ONCE(is_ns_init_id(ns)); - if (!atomic_dec_and_test(&ns->__ns_ref_active)) + if (!atomic_dec_and_test(&ns->__ns_ref_active)) { + VFS_WARN_ON_ONCE(__ns_ref_active_read(ns) < 0); return; + } } } @@ -280,12 +284,16 @@ void __ns_ref_active_put(struct ns_common *ns) */ void __ns_ref_active_get(struct ns_common *ns) { + int prev; + /* Initial namespaces are always active. */ if (is_ns_init_id(ns)) return; /* If we didn't resurrect the namespace we're done. */ - if (atomic_fetch_add(1, &ns->__ns_ref_active)) + prev = atomic_fetch_add(1, &ns->__ns_ref_active); + VFS_WARN_ON_ONCE(prev < 0); + if (likely(prev)) return; /* @@ -298,7 +306,9 @@ void __ns_ref_active_get(struct ns_common *ns) return; VFS_WARN_ON_ONCE(is_ns_init_id(ns)); - if (atomic_fetch_add(1, &ns->__ns_ref_active)) + prev = atomic_fetch_add(1, &ns->__ns_ref_active); + VFS_WARN_ON_ONCE(prev < 0); + if (likely(prev)) return; } } |