diff options
| author | Andrey Konovalov <andreyknvl@google.com> | 2023-11-20 18:47:19 +0100 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2023-12-10 16:51:48 -0800 |
| commit | 773688a6cb24b0b3c2ba40354d883348a2befa38 (patch) | |
| tree | 7777e7a212937ca49769a84c64e90a77de9c1a74 /mm/kasan/generic.c | |
| parent | 2d5524635b00fc90016577e1a18c21682b1bb913 (diff) | |
| download | linux-773688a6cb24b0b3c2ba40354d883348a2befa38.tar.gz linux-773688a6cb24b0b3c2ba40354d883348a2befa38.tar.bz2 linux-773688a6cb24b0b3c2ba40354d883348a2befa38.zip | |
kasan: use stack_depot_put for Generic mode
Evict alloc/free stack traces from the stack depot for Generic KASAN once
they are evicted from the quaratine.
For auxiliary stack traces, evict the oldest stack trace once a new one is
saved (KASAN only keeps references to the last two).
Also evict all saved stack traces on krealloc.
To avoid double-evicting and mis-evicting stack traces (in case KASAN's
metadata was corrupted), reset KASAN's per-object metadata that stores
stack depot handles when the object is initialized and when it's evicted
from the quarantine.
Note that stack_depot_put is no-op if the handle is 0.
Link: https://lkml.kernel.org/r/5cef104d9b842899489b4054fe8d1339a71acee0.1700502145.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/kasan/generic.c')
| -rw-r--r-- | mm/kasan/generic.c | 22 |
1 files changed, 18 insertions, 4 deletions
diff --git a/mm/kasan/generic.c b/mm/kasan/generic.c index 5d168c9afb32..50cc519e23f4 100644 --- a/mm/kasan/generic.c +++ b/mm/kasan/generic.c @@ -449,10 +449,14 @@ struct kasan_free_meta *kasan_get_free_meta(struct kmem_cache *cache, void kasan_init_object_meta(struct kmem_cache *cache, const void *object) { struct kasan_alloc_meta *alloc_meta; + struct kasan_free_meta *free_meta; alloc_meta = kasan_get_alloc_meta(cache, object); if (alloc_meta) __memset(alloc_meta, 0, sizeof(*alloc_meta)); + free_meta = kasan_get_free_meta(cache, object); + if (free_meta) + __memset(free_meta, 0, sizeof(*free_meta)); } size_t kasan_metadata_size(struct kmem_cache *cache, bool in_object) @@ -489,18 +493,20 @@ 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]); alloc_meta->aux_stack[1] = alloc_meta->aux_stack[0]; alloc_meta->aux_stack[0] = kasan_save_stack(0, depot_flags); } void kasan_record_aux_stack(void *addr) { - return __kasan_record_aux_stack(addr, STACK_DEPOT_FLAG_CAN_ALLOC); + return __kasan_record_aux_stack(addr, + STACK_DEPOT_FLAG_CAN_ALLOC | STACK_DEPOT_FLAG_GET); } void kasan_record_aux_stack_noalloc(void *addr) { - return __kasan_record_aux_stack(addr, 0); + return __kasan_record_aux_stack(addr, STACK_DEPOT_FLAG_GET); } void kasan_save_alloc_info(struct kmem_cache *cache, void *object, gfp_t flags) @@ -508,8 +514,16 @@ void kasan_save_alloc_info(struct kmem_cache *cache, void *object, gfp_t flags) struct kasan_alloc_meta *alloc_meta; alloc_meta = kasan_get_alloc_meta(cache, object); - if (alloc_meta) - kasan_set_track(&alloc_meta->alloc_track, flags); + if (!alloc_meta) + return; + + /* Evict previous stack traces (might exist for krealloc). */ + stack_depot_put(alloc_meta->alloc_track.stack); + stack_depot_put(alloc_meta->aux_stack[0]); + stack_depot_put(alloc_meta->aux_stack[1]); + __memset(alloc_meta, 0, sizeof(*alloc_meta)); + + kasan_set_track(&alloc_meta->alloc_track, flags); } void kasan_save_free_info(struct kmem_cache *cache, void *object) |