From: Christian Brauner Date: Sat, 1 Jul 2023 06:44:44 +0000 (+0200) Subject: pid: use struct_size_t() helper X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=dd546618ba704be4f3724a11e5a194052c551f08;p=linux.git pid: use struct_size_t() helper Before commit d67790ddf021 ("overflow: Add struct_size_t() helper") only struct_size() existed, which expects a valid pointer instance containing the flexible array. However, when we determine the default struct pid allocation size for the associated kmem cache of a pid namespace we need to take the nesting depth of the pid namespace into account without an variable instance necessarily being available. In commit b69f0aeb0689 ("pid: Replace struct pid 1-element array with flex-array") we used to handle this the old fashioned way and cast NULL to a struct pid pointer type. However, we do apparently have a dedicated struct_size_t() helper for exactly this case. So switch to that. Suggested-by: Kees Cook Suggested-by: Linus Torvalds Signed-off-by: Christian Brauner Signed-off-by: Linus Torvalds --- diff --git a/kernel/pid.c b/kernel/pid.c index 8bce3aebc949f..6a1d23a11026c 100644 --- a/kernel/pid.c +++ b/kernel/pid.c @@ -657,7 +657,7 @@ void __init pid_idr_init(void) idr_init(&init_pid_ns.idr); init_pid_ns.pid_cachep = kmem_cache_create("pid", - struct_size((struct pid *)NULL, numbers, 1), + struct_size_t(struct pid, numbers, 1), __alignof__(struct pid), SLAB_HWCACHE_ALIGN | SLAB_PANIC | SLAB_ACCOUNT, NULL); diff --git a/kernel/pid_namespace.c b/kernel/pid_namespace.c index 70a929784a5db..0bf44afe04dd1 100644 --- a/kernel/pid_namespace.c +++ b/kernel/pid_namespace.c @@ -48,7 +48,7 @@ static struct kmem_cache *create_pid_cachep(unsigned int level) return kc; snprintf(name, sizeof(name), "pid_%u", level + 1); - len = struct_size((struct pid *)NULL, numbers, level + 1); + len = struct_size_t(struct pid, numbers, level + 1); mutex_lock(&pid_caches_mutex); /* Name collision forces to do allocation under mutex. */ if (!*pkc)