The patch titled Subject: kasan: better identify bug types for tag-based modes has been added to the -mm mm-unstable branch. Its filename is kasan-better-identify-bug-types-for-tag-based-modes.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/kasan-better-identify-bug-types-for-tag-based-modes.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Andrey Konovalov <andreyknvl@xxxxxxxxxx> Subject: kasan: better identify bug types for tag-based modes Date: Mon, 5 Sep 2022 23:05:48 +0200 Identify the bug type for the tag-based modes based on the stack trace entries found in the stack ring. If a free entry is found first (meaning that it was added last), mark the bug as use-after-free. If an alloc entry is found first, mark the bug as slab-out-of-bounds. Otherwise, assign the common bug type. This change returns the functionalify of the previously dropped CONFIG_KASAN_TAGS_IDENTIFY. Link: https://lkml.kernel.org/r/13ce7fa07d9d995caedd1439dfae4d51401842f2.1662411800.git.andreyknvl@xxxxxxxxxx Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx> Reviewed-by: Marco Elver <elver@xxxxxxxxxx> Cc: Alexander Potapenko <glider@xxxxxxxxxx> Cc: Andrey Ryabinin <ryabinin.a.a@xxxxxxxxx> Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx> Cc: Evgenii Stepanov <eugenis@xxxxxxxxxx> Cc: Peter Collingbourne <pcc@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/kasan/report_tags.c | 25 +++++++++++++++++++++---- 1 file changed, 21 insertions(+), 4 deletions(-) --- a/mm/kasan/report_tags.c~kasan-better-identify-bug-types-for-tag-based-modes +++ a/mm/kasan/report_tags.c @@ -10,7 +10,7 @@ extern struct kasan_stack_ring stack_ring; -static const char *get_bug_type(struct kasan_report_info *info) +static const char *get_common_bug_type(struct kasan_report_info *info) { /* * If access_size is a negative number, then it has reason to be @@ -37,9 +37,8 @@ void kasan_complete_mode_report_info(str bool is_free; bool alloc_found = false, free_found = false; - info->bug_type = get_bug_type(info); - - if (!info->cache || !info->object) + if (!info->cache || !info->object) { + info->bug_type = get_common_bug_type(info); return; } @@ -84,6 +83,13 @@ void kasan_complete_mode_report_info(str info->free_track.pid = pid; info->free_track.stack = stack; free_found = true; + + /* + * If a free entry is found first, the bug is likely + * a use-after-free. + */ + if (!info->bug_type) + info->bug_type = "use-after-free"; } else { /* Second alloc of the same object. Give up. */ if (alloc_found) @@ -92,8 +98,19 @@ void kasan_complete_mode_report_info(str info->alloc_track.pid = pid; info->alloc_track.stack = stack; alloc_found = true; + + /* + * If an alloc entry is found first, the bug is likely + * an out-of-bounds. + */ + if (!info->bug_type) + info->bug_type = "slab-out-of-bounds"; } } write_unlock_irqrestore(&stack_ring.lock, flags); + + /* Assign the common bug type if no entries were found. */ + if (!info->bug_type) + info->bug_type = get_common_bug_type(info); } _ Patches currently in -mm which might be from andreyknvl@xxxxxxxxxx are kasan-check-kasan_no_free_meta-in-__kasan_metadata_size.patch kasan-rename-kasan_set__info-to-kasan_save__info.patch kasan-move-is_kmalloc-check-out-of-save_alloc_info.patch kasan-split-save_alloc_info-implementations.patch kasan-drop-config_kasan_tags_identify.patch kasan-introduce-kasan_print_aux_stacks.patch kasan-introduce-kasan_get_alloc_track.patch kasan-introduce-kasan_init_object_meta.patch kasan-clear-metadata-functions-for-tag-based-modes.patch kasan-move-kasan_get__meta-to-genericc.patch kasan-introduce-kasan_requires_meta.patch kasan-introduce-kasan_init_cache_meta.patch kasan-drop-config_kasan_generic-check-from-kasan_init_cache_meta.patch kasan-only-define-kasan_metadata_size-for-generic-mode.patch kasan-only-define-kasan_never_merge-for-generic-mode.patch kasan-only-define-metadata-offsets-for-generic-mode.patch kasan-only-define-metadata-structs-for-generic-mode.patch kasan-only-define-kasan_cache_create-for-generic-mode.patch kasan-pass-tagged-pointers-to-kasan_save_alloc-free_info.patch kasan-move-kasan_get_alloc-free_track-definitions.patch kasan-cosmetic-changes-in-reportc.patch kasan-use-virt_addr_valid-in-kasan_addr_to_page-slab.patch kasan-use-kasan_addr_to_slab-in-print_address_description.patch kasan-make-kasan_addr_to_page-static.patch kasan-simplify-print_report.patch kasan-introduce-complete_report_info.patch kasan-fill-in-cache-and-object-in-complete_report_info.patch kasan-rework-function-arguments-in-reportc.patch kasan-introduce-kasan_complete_mode_report_info.patch kasan-implement-stack-ring-for-tag-based-modes.patch kasan-support-kasanstacktrace-for-sw_tags.patch kasan-dynamically-allocate-stack-ring-entries.patch kasan-better-identify-bug-types-for-tag-based-modes.patch kasan-add-another-use-after-free-test.patch kasan-move-tests-to-mm-kasan.patch