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-rw-r--r--mm/kasan/generic.c32
-rw-r--r--mm/kasan/kasan.h8
2 files changed, 37 insertions, 3 deletions
diff --git a/mm/kasan/generic.c b/mm/kasan/generic.c
index 54e20b2bc3e1..55e6b5db2cae 100644
--- a/mm/kasan/generic.c
+++ b/mm/kasan/generic.c
@@ -25,6 +25,7 @@
#include <linux/sched.h>
#include <linux/sched/task_stack.h>
#include <linux/slab.h>
+#include <linux/spinlock.h>
#include <linux/stackdepot.h>
#include <linux/stacktrace.h>
#include <linux/string.h>
@@ -471,8 +472,18 @@ void kasan_init_object_meta(struct kmem_cache *cache, const void *object)
struct kasan_free_meta *free_meta;
alloc_meta = kasan_get_alloc_meta(cache, object);
- if (alloc_meta)
+ if (alloc_meta) {
__memset(alloc_meta, 0, sizeof(*alloc_meta));
+
+ /*
+ * Temporarily disable KASAN bug reporting to allow instrumented
+ * raw_spin_lock_init to access aux_lock, which resides inside
+ * of a redzone.
+ */
+ kasan_disable_current();
+ raw_spin_lock_init(&alloc_meta->aux_lock);
+ kasan_enable_current();
+ }
free_meta = kasan_get_free_meta(cache, object);
if (free_meta)
__memset(free_meta, 0, sizeof(*free_meta));
@@ -502,6 +513,8 @@ static void __kasan_record_aux_stack(void *addr, depot_flags_t depot_flags)
struct kmem_cache *cache;
struct kasan_alloc_meta *alloc_meta;
void *object;
+ depot_stack_handle_t new_handle, old_handle;
+ unsigned long flags;
if (is_kfence_address(addr) || !slab)
return;
@@ -512,9 +525,22 @@ static void __kasan_record_aux_stack(void *addr, depot_flags_t depot_flags)
if (!alloc_meta)
return;
- stack_depot_put(alloc_meta->aux_stack[1]);
+ new_handle = kasan_save_stack(0, depot_flags);
+
+ /*
+ * Temporarily disable KASAN bug reporting to allow instrumented
+ * spinlock functions to access aux_lock, which resides inside of a
+ * redzone.
+ */
+ kasan_disable_current();
+ raw_spin_lock_irqsave(&alloc_meta->aux_lock, flags);
+ old_handle = alloc_meta->aux_stack[1];
alloc_meta->aux_stack[1] = alloc_meta->aux_stack[0];
- alloc_meta->aux_stack[0] = kasan_save_stack(0, depot_flags);
+ alloc_meta->aux_stack[0] = new_handle;
+ raw_spin_unlock_irqrestore(&alloc_meta->aux_lock, flags);
+ kasan_enable_current();
+
+ stack_depot_put(old_handle);
}
void kasan_record_aux_stack(void *addr)
diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
index 5e298e3ac909..69e4f5e58e33 100644
--- a/mm/kasan/kasan.h
+++ b/mm/kasan/kasan.h
@@ -6,6 +6,7 @@
#include <linux/kasan.h>
#include <linux/kasan-tags.h>
#include <linux/kfence.h>
+#include <linux/spinlock.h>
#include <linux/stackdepot.h>
#if defined(CONFIG_KASAN_SW_TAGS) || defined(CONFIG_KASAN_HW_TAGS)
@@ -249,6 +250,13 @@ struct kasan_global {
struct kasan_alloc_meta {
struct kasan_track alloc_track;
/* Free track is stored in kasan_free_meta. */
+ /*
+ * aux_lock protects aux_stack from accesses from concurrent
+ * kasan_record_aux_stack calls. It is a raw spinlock to avoid sleeping
+ * on RT kernels, as kasan_record_aux_stack_noalloc can be called from
+ * non-sleepable contexts.
+ */
+ raw_spinlock_t aux_lock;
depot_stack_handle_t aux_stack[2];
};