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-rw-r--r--mm/kasan/common.c41
-rw-r--r--mm/kasan/generic.c43
-rw-r--r--mm/kasan/generic_report.c1
-rw-r--r--mm/kasan/kasan.h23
-rw-r--r--mm/kasan/quarantine.c1
-rw-r--r--mm/kasan/report.c54
-rw-r--r--mm/kasan/tags.c37
7 files changed, 134 insertions, 66 deletions
diff --git a/mm/kasan/common.c b/mm/kasan/common.c
index 757d4074fe28..950fd372a07e 100644
--- a/mm/kasan/common.c
+++ b/mm/kasan/common.c
@@ -40,7 +40,7 @@
#include "kasan.h"
#include "../slab.h"
-static inline depot_stack_handle_t save_stack(gfp_t flags)
+depot_stack_handle_t kasan_save_stack(gfp_t flags)
{
unsigned long entries[KASAN_STACK_DEPTH];
unsigned int nr_entries;
@@ -50,10 +50,10 @@ static inline depot_stack_handle_t save_stack(gfp_t flags)
return stack_depot_save(entries, nr_entries, flags);
}
-static inline void set_track(struct kasan_track *track, gfp_t flags)
+void kasan_set_track(struct kasan_track *track, gfp_t flags)
{
track->pid = current->pid;
- track->stack = save_stack(flags);
+ track->stack = kasan_save_stack(flags);
}
void kasan_enable_current(void)
@@ -180,21 +180,6 @@ asmlinkage void kasan_unpoison_task_stack_below(const void *watermark)
kasan_unpoison_shadow(base, watermark - base);
}
-/*
- * Clear all poison for the region between the current SP and a provided
- * watermark value, as is sometimes required prior to hand-crafted asm function
- * returns in the middle of functions.
- */
-void kasan_unpoison_stack_above_sp_to(const void *watermark)
-{
- const void *sp = __builtin_frame_address(0);
- size_t size = watermark - sp;
-
- if (WARN_ON(sp > watermark))
- return;
- kasan_unpoison_shadow(sp, size);
-}
-
void kasan_alloc_pages(struct page *page, unsigned int order)
{
u8 tag;
@@ -298,24 +283,6 @@ struct kasan_free_meta *get_free_info(struct kmem_cache *cache,
return (void *)object + cache->kasan_info.free_meta_offset;
}
-
-static void kasan_set_free_info(struct kmem_cache *cache,
- void *object, u8 tag)
-{
- struct kasan_alloc_meta *alloc_meta;
- u8 idx = 0;
-
- alloc_meta = get_alloc_info(cache, object);
-
-#ifdef CONFIG_KASAN_SW_TAGS_IDENTIFY
- idx = alloc_meta->free_track_idx;
- alloc_meta->free_pointer_tag[idx] = tag;
- alloc_meta->free_track_idx = (idx + 1) % KASAN_NR_FREE_STACKS;
-#endif
-
- set_track(&alloc_meta->free_track[idx], GFP_NOWAIT);
-}
-
void kasan_poison_slab(struct page *page)
{
unsigned long i;
@@ -491,7 +458,7 @@ static void *__kasan_kmalloc(struct kmem_cache *cache, const void *object,
KASAN_KMALLOC_REDZONE);
if (cache->flags & SLAB_KASAN)
- set_track(&get_alloc_info(cache, object)->alloc_track, flags);
+ kasan_set_track(&get_alloc_info(cache, object)->alloc_track, flags);
return set_tag(object, tag);
}
diff --git a/mm/kasan/generic.c b/mm/kasan/generic.c
index 098a7dbaced6..248264b9cb76 100644
--- a/mm/kasan/generic.c
+++ b/mm/kasan/generic.c
@@ -324,3 +324,46 @@ DEFINE_ASAN_SET_SHADOW(f2);
DEFINE_ASAN_SET_SHADOW(f3);
DEFINE_ASAN_SET_SHADOW(f5);
DEFINE_ASAN_SET_SHADOW(f8);
+
+void kasan_record_aux_stack(void *addr)
+{
+ struct page *page = kasan_addr_to_page(addr);
+ struct kmem_cache *cache;
+ struct kasan_alloc_meta *alloc_info;
+ void *object;
+
+ if (!(page && PageSlab(page)))
+ return;
+
+ cache = page->slab_cache;
+ object = nearest_obj(cache, page, addr);
+ alloc_info = get_alloc_info(cache, object);
+
+ /*
+ * record the last two call_rcu() call stacks.
+ */
+ alloc_info->aux_stack[1] = alloc_info->aux_stack[0];
+ alloc_info->aux_stack[0] = kasan_save_stack(GFP_NOWAIT);
+}
+
+void kasan_set_free_info(struct kmem_cache *cache,
+ void *object, u8 tag)
+{
+ struct kasan_free_meta *free_meta;
+
+ free_meta = get_free_info(cache, object);
+ kasan_set_track(&free_meta->free_track, GFP_NOWAIT);
+
+ /*
+ * the object was freed and has free track set
+ */
+ *(u8 *)kasan_mem_to_shadow(object) = KASAN_KMALLOC_FREETRACK;
+}
+
+struct kasan_track *kasan_get_free_track(struct kmem_cache *cache,
+ void *object, u8 tag)
+{
+ if (*(u8 *)kasan_mem_to_shadow(object) != KASAN_KMALLOC_FREETRACK)
+ return NULL;
+ return &get_free_info(cache, object)->free_track;
+}
diff --git a/mm/kasan/generic_report.c b/mm/kasan/generic_report.c
index e200acb2d292..a38c7a9e192a 100644
--- a/mm/kasan/generic_report.c
+++ b/mm/kasan/generic_report.c
@@ -80,6 +80,7 @@ static const char *get_shadow_bug_type(struct kasan_access_info *info)
break;
case KASAN_FREE_PAGE:
case KASAN_KMALLOC_FREE:
+ case KASAN_KMALLOC_FREETRACK:
bug_type = "use-after-free";
break;
case KASAN_ALLOCA_LEFT:
diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
index cfade6413528..ac499456740f 100644
--- a/mm/kasan/kasan.h
+++ b/mm/kasan/kasan.h
@@ -17,15 +17,17 @@
#define KASAN_PAGE_REDZONE 0xFE /* redzone for kmalloc_large allocations */
#define KASAN_KMALLOC_REDZONE 0xFC /* redzone inside slub object */
#define KASAN_KMALLOC_FREE 0xFB /* object was freed (kmem_cache_free/kfree) */
+#define KASAN_KMALLOC_FREETRACK 0xFA /* object was freed and has free track set */
#else
#define KASAN_FREE_PAGE KASAN_TAG_INVALID
#define KASAN_PAGE_REDZONE KASAN_TAG_INVALID
#define KASAN_KMALLOC_REDZONE KASAN_TAG_INVALID
#define KASAN_KMALLOC_FREE KASAN_TAG_INVALID
+#define KASAN_KMALLOC_FREETRACK KASAN_TAG_INVALID
#endif
-#define KASAN_GLOBAL_REDZONE 0xFA /* redzone for global variable */
-#define KASAN_VMALLOC_INVALID 0xF9 /* unallocated space in vmapped page */
+#define KASAN_GLOBAL_REDZONE 0xF9 /* redzone for global variable */
+#define KASAN_VMALLOC_INVALID 0xF8 /* unallocated space in vmapped page */
/*
* Stack redzone shadow values
@@ -104,7 +106,15 @@ struct kasan_track {
struct kasan_alloc_meta {
struct kasan_track alloc_track;
+#ifdef CONFIG_KASAN_GENERIC
+ /*
+ * call_rcu() call stack is stored into struct kasan_alloc_meta.
+ * The free stack is stored into struct kasan_free_meta.
+ */
+ depot_stack_handle_t aux_stack[2];
+#else
struct kasan_track free_track[KASAN_NR_FREE_STACKS];
+#endif
#ifdef CONFIG_KASAN_SW_TAGS_IDENTIFY
u8 free_pointer_tag[KASAN_NR_FREE_STACKS];
u8 free_track_idx;
@@ -119,6 +129,9 @@ struct kasan_free_meta {
* Otherwise it might be used for the allocator freelist.
*/
struct qlist_node quarantine_link;
+#ifdef CONFIG_KASAN_GENERIC
+ struct kasan_track free_track;
+#endif
};
struct kasan_alloc_meta *get_alloc_info(struct kmem_cache *cache,
@@ -159,6 +172,12 @@ void kasan_report_invalid_free(void *object, unsigned long ip);
struct page *kasan_addr_to_page(const void *addr);
+depot_stack_handle_t kasan_save_stack(gfp_t flags);
+void kasan_set_track(struct kasan_track *track, gfp_t flags);
+void kasan_set_free_info(struct kmem_cache *cache, void *object, u8 tag);
+struct kasan_track *kasan_get_free_track(struct kmem_cache *cache,
+ void *object, u8 tag);
+
#if defined(CONFIG_KASAN_GENERIC) && \
(defined(CONFIG_SLAB) || defined(CONFIG_SLUB))
void quarantine_put(struct kasan_free_meta *info, struct kmem_cache *cache);
diff --git a/mm/kasan/quarantine.c b/mm/kasan/quarantine.c
index 978bc4a3eb51..4c5375810449 100644
--- a/mm/kasan/quarantine.c
+++ b/mm/kasan/quarantine.c
@@ -145,6 +145,7 @@ static void qlink_free(struct qlist_node *qlink, struct kmem_cache *cache)
if (IS_ENABLED(CONFIG_SLAB))
local_irq_save(flags);
+ *(u8 *)kasan_mem_to_shadow(object) = KASAN_KMALLOC_FREE;
___cache_free(cache, object, _THIS_IP_);
if (IS_ENABLED(CONFIG_SLAB))
diff --git a/mm/kasan/report.c b/mm/kasan/report.c
index 51ec45407a0b..4f49fa6cd1aa 100644
--- a/mm/kasan/report.c
+++ b/mm/kasan/report.c
@@ -106,15 +106,20 @@ static void end_report(unsigned long *flags)
kasan_enable_current();
}
+static void print_stack(depot_stack_handle_t stack)
+{
+ unsigned long *entries;
+ unsigned int nr_entries;
+
+ nr_entries = stack_depot_fetch(stack, &entries);
+ stack_trace_print(entries, nr_entries, 0);
+}
+
static void print_track(struct kasan_track *track, const char *prefix)
{
pr_err("%s by task %u:\n", prefix, track->pid);
if (track->stack) {
- unsigned long *entries;
- unsigned int nr_entries;
-
- nr_entries = stack_depot_fetch(track->stack, &entries);
- stack_trace_print(entries, nr_entries, 0);
+ print_stack(track->stack);
} else {
pr_err("(stack is not available)\n");
}
@@ -160,26 +165,6 @@ static void describe_object_addr(struct kmem_cache *cache, void *object,
(void *)(object_addr + cache->object_size));
}
-static struct kasan_track *kasan_get_free_track(struct kmem_cache *cache,
- void *object, u8 tag)
-{
- struct kasan_alloc_meta *alloc_meta;
- int i = 0;
-
- alloc_meta = get_alloc_info(cache, object);
-
-#ifdef CONFIG_KASAN_SW_TAGS_IDENTIFY
- for (i = 0; i < KASAN_NR_FREE_STACKS; i++) {
- if (alloc_meta->free_pointer_tag[i] == tag)
- break;
- }
- if (i == KASAN_NR_FREE_STACKS)
- i = alloc_meta->free_track_idx;
-#endif
-
- return &alloc_meta->free_track[i];
-}
-
static void describe_object(struct kmem_cache *cache, void *object,
const void *addr, u8 tag)
{
@@ -191,8 +176,23 @@ static void describe_object(struct kmem_cache *cache, void *object,
print_track(&alloc_info->alloc_track, "Allocated");
pr_err("\n");
free_track = kasan_get_free_track(cache, object, tag);
- print_track(free_track, "Freed");
- pr_err("\n");
+ if (free_track) {
+ print_track(free_track, "Freed");
+ pr_err("\n");
+ }
+
+#ifdef CONFIG_KASAN_GENERIC
+ if (alloc_info->aux_stack[0]) {
+ pr_err("Last call_rcu():\n");
+ print_stack(alloc_info->aux_stack[0]);
+ pr_err("\n");
+ }
+ if (alloc_info->aux_stack[1]) {
+ pr_err("Second to last call_rcu():\n");
+ print_stack(alloc_info->aux_stack[1]);
+ pr_err("\n");
+ }
+#endif
}
describe_object_addr(cache, object, addr);
diff --git a/mm/kasan/tags.c b/mm/kasan/tags.c
index 8a959fdd30e3..e02a36a51f42 100644
--- a/mm/kasan/tags.c
+++ b/mm/kasan/tags.c
@@ -161,3 +161,40 @@ void __hwasan_tag_memory(unsigned long addr, u8 tag, unsigned long size)
kasan_poison_shadow((void *)addr, size, tag);
}
EXPORT_SYMBOL(__hwasan_tag_memory);
+
+void kasan_set_free_info(struct kmem_cache *cache,
+ void *object, u8 tag)
+{
+ struct kasan_alloc_meta *alloc_meta;
+ u8 idx = 0;
+
+ alloc_meta = get_alloc_info(cache, object);
+
+#ifdef CONFIG_KASAN_SW_TAGS_IDENTIFY
+ idx = alloc_meta->free_track_idx;
+ alloc_meta->free_pointer_tag[idx] = tag;
+ alloc_meta->free_track_idx = (idx + 1) % KASAN_NR_FREE_STACKS;
+#endif
+
+ kasan_set_track(&alloc_meta->free_track[idx], GFP_NOWAIT);
+}
+
+struct kasan_track *kasan_get_free_track(struct kmem_cache *cache,
+ void *object, u8 tag)
+{
+ struct kasan_alloc_meta *alloc_meta;
+ int i = 0;
+
+ alloc_meta = get_alloc_info(cache, object);
+
+#ifdef CONFIG_KASAN_SW_TAGS_IDENTIFY
+ for (i = 0; i < KASAN_NR_FREE_STACKS; i++) {
+ if (alloc_meta->free_pointer_tag[i] == tag)
+ break;
+ }
+ if (i == KASAN_NR_FREE_STACKS)
+ i = alloc_meta->free_track_idx;
+#endif
+
+ return &alloc_meta->free_track[i];
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-05-22 17:10:48 +0000