The patch titled Subject: kasan: decode stack frame only with KASAN_STACK_ENABLE has been added to the -mm tree. Its filename is kasan-decode-stack-frame-only-with-kasan_stack_enable.patch This patch should soon appear at https://ozlabs.org/~akpm/mmots/broken-out/kasan-decode-stack-frame-only-with-kasan_stack_enable.patch and later at https://ozlabs.org/~akpm/mmotm/broken-out/kasan-decode-stack-frame-only-with-kasan_stack_enable.patch 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 and is updated there every 3-4 working days ------------------------------------------------------ From: Andrey Konovalov <andreyknvl@xxxxxxxxxx> Subject: kasan: decode stack frame only with KASAN_STACK_ENABLE Decoding routines aren't needed when CONFIG_KASAN_STACK_ENABLE is not enabled. Currently only generic KASAN mode implements stack error reporting. No functional changes for software modes. Link: https://lkml.kernel.org/r/05a24db36f5ec876af876a299bbea98c29468ebd.1606161801.git.andreyknvl@xxxxxxxxxx Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@xxxxxxx> Reviewed-by: Marco Elver <elver@xxxxxxxxxx> Reviewed-by: Alexander Potapenko <glider@xxxxxxxxxx> Tested-by: Vincenzo Frascino <vincenzo.frascino@xxxxxxx> Cc: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx> Cc: Branislav Rankov <Branislav.Rankov@xxxxxxx> Cc: Catalin Marinas <catalin.marinas@xxxxxxx> Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx> Cc: Evgenii Stepanov <eugenis@xxxxxxxxxx> Cc: Kevin Brodsky <kevin.brodsky@xxxxxxx> Cc: Vasily Gorbik <gor@xxxxxxxxxxxxx> Cc: Will Deacon <will.deacon@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/kasan/kasan.h | 6 + mm/kasan/report.c | 162 ------------------------------------ mm/kasan/report_generic.c | 162 ++++++++++++++++++++++++++++++++++++ 3 files changed, 168 insertions(+), 162 deletions(-) --- a/mm/kasan/kasan.h~kasan-decode-stack-frame-only-with-kasan_stack_enable +++ a/mm/kasan/kasan.h @@ -171,6 +171,12 @@ bool check_invalid_free(void *addr); void *find_first_bad_addr(void *addr, size_t size); const char *get_bug_type(struct kasan_access_info *info); +#if defined(CONFIG_KASAN_GENERIC) && CONFIG_KASAN_STACK +void print_address_stack_frame(const void *addr); +#else +static inline void print_address_stack_frame(const void *addr) { } +#endif + bool kasan_report(unsigned long addr, size_t size, bool is_write, unsigned long ip); void kasan_report_invalid_free(void *object, unsigned long ip); --- a/mm/kasan/report.c~kasan-decode-stack-frame-only-with-kasan_stack_enable +++ a/mm/kasan/report.c @@ -211,168 +211,6 @@ static inline bool init_task_stack_addr( sizeof(init_thread_union.stack)); } -static bool __must_check tokenize_frame_descr(const char **frame_descr, - char *token, size_t max_tok_len, - unsigned long *value) -{ - const char *sep = strchr(*frame_descr, ' '); - - if (sep == NULL) - sep = *frame_descr + strlen(*frame_descr); - - if (token != NULL) { - const size_t tok_len = sep - *frame_descr; - - if (tok_len + 1 > max_tok_len) { - pr_err("KASAN internal error: frame description too long: %s\n", - *frame_descr); - return false; - } - - /* Copy token (+ 1 byte for '\0'). */ - strlcpy(token, *frame_descr, tok_len + 1); - } - - /* Advance frame_descr past separator. */ - *frame_descr = sep + 1; - - if (value != NULL && kstrtoul(token, 10, value)) { - pr_err("KASAN internal error: not a valid number: %s\n", token); - return false; - } - - return true; -} - -static void print_decoded_frame_descr(const char *frame_descr) -{ - /* - * We need to parse the following string: - * "n alloc_1 alloc_2 ... alloc_n" - * where alloc_i looks like - * "offset size len name" - * or "offset size len name:line". - */ - - char token[64]; - unsigned long num_objects; - - if (!tokenize_frame_descr(&frame_descr, token, sizeof(token), - &num_objects)) - return; - - pr_err("\n"); - pr_err("this frame has %lu %s:\n", num_objects, - num_objects == 1 ? "object" : "objects"); - - while (num_objects--) { - unsigned long offset; - unsigned long size; - - /* access offset */ - if (!tokenize_frame_descr(&frame_descr, token, sizeof(token), - &offset)) - return; - /* access size */ - if (!tokenize_frame_descr(&frame_descr, token, sizeof(token), - &size)) - return; - /* name length (unused) */ - if (!tokenize_frame_descr(&frame_descr, NULL, 0, NULL)) - return; - /* object name */ - if (!tokenize_frame_descr(&frame_descr, token, sizeof(token), - NULL)) - return; - - /* Strip line number; without filename it's not very helpful. */ - strreplace(token, ':', '\0'); - - /* Finally, print object information. */ - pr_err(" [%lu, %lu) '%s'", offset, offset + size, token); - } -} - -static bool __must_check get_address_stack_frame_info(const void *addr, - unsigned long *offset, - const char **frame_descr, - const void **frame_pc) -{ - unsigned long aligned_addr; - unsigned long mem_ptr; - const u8 *shadow_bottom; - const u8 *shadow_ptr; - const unsigned long *frame; - - BUILD_BUG_ON(IS_ENABLED(CONFIG_STACK_GROWSUP)); - - /* - * NOTE: We currently only support printing frame information for - * accesses to the task's own stack. - */ - if (!object_is_on_stack(addr)) - return false; - - aligned_addr = round_down((unsigned long)addr, sizeof(long)); - mem_ptr = round_down(aligned_addr, KASAN_GRANULE_SIZE); - shadow_ptr = kasan_mem_to_shadow((void *)aligned_addr); - shadow_bottom = kasan_mem_to_shadow(end_of_stack(current)); - - while (shadow_ptr >= shadow_bottom && *shadow_ptr != KASAN_STACK_LEFT) { - shadow_ptr--; - mem_ptr -= KASAN_GRANULE_SIZE; - } - - while (shadow_ptr >= shadow_bottom && *shadow_ptr == KASAN_STACK_LEFT) { - shadow_ptr--; - mem_ptr -= KASAN_GRANULE_SIZE; - } - - if (shadow_ptr < shadow_bottom) - return false; - - frame = (const unsigned long *)(mem_ptr + KASAN_GRANULE_SIZE); - if (frame[0] != KASAN_CURRENT_STACK_FRAME_MAGIC) { - pr_err("KASAN internal error: frame info validation failed; invalid marker: %lu\n", - frame[0]); - return false; - } - - *offset = (unsigned long)addr - (unsigned long)frame; - *frame_descr = (const char *)frame[1]; - *frame_pc = (void *)frame[2]; - - return true; -} - -static void print_address_stack_frame(const void *addr) -{ - unsigned long offset; - const char *frame_descr; - const void *frame_pc; - - if (IS_ENABLED(CONFIG_KASAN_SW_TAGS)) - return; - - if (!get_address_stack_frame_info(addr, &offset, &frame_descr, - &frame_pc)) - return; - - /* - * get_address_stack_frame_info only returns true if the given addr is - * on the current task's stack. - */ - pr_err("\n"); - pr_err("addr %px is located in stack of task %s/%d at offset %lu in frame:\n", - addr, current->comm, task_pid_nr(current), offset); - pr_err(" %pS\n", frame_pc); - - if (!frame_descr) - return; - - print_decoded_frame_descr(frame_descr); -} - static void print_address_description(void *addr, u8 tag) { struct page *page = kasan_addr_to_page(addr); --- a/mm/kasan/report_generic.c~kasan-decode-stack-frame-only-with-kasan_stack_enable +++ a/mm/kasan/report_generic.c @@ -16,6 +16,7 @@ #include <linux/mm.h> #include <linux/printk.h> #include <linux/sched.h> +#include <linux/sched/task_stack.h> #include <linux/slab.h> #include <linux/stackdepot.h> #include <linux/stacktrace.h> @@ -122,6 +123,167 @@ const char *get_bug_type(struct kasan_ac return get_wild_bug_type(info); } +#if CONFIG_KASAN_STACK +static bool __must_check tokenize_frame_descr(const char **frame_descr, + char *token, size_t max_tok_len, + unsigned long *value) +{ + const char *sep = strchr(*frame_descr, ' '); + + if (sep == NULL) + sep = *frame_descr + strlen(*frame_descr); + + if (token != NULL) { + const size_t tok_len = sep - *frame_descr; + + if (tok_len + 1 > max_tok_len) { + pr_err("KASAN internal error: frame description too long: %s\n", + *frame_descr); + return false; + } + + /* Copy token (+ 1 byte for '\0'). */ + strlcpy(token, *frame_descr, tok_len + 1); + } + + /* Advance frame_descr past separator. */ + *frame_descr = sep + 1; + + if (value != NULL && kstrtoul(token, 10, value)) { + pr_err("KASAN internal error: not a valid number: %s\n", token); + return false; + } + + return true; +} + +static void print_decoded_frame_descr(const char *frame_descr) +{ + /* + * We need to parse the following string: + * "n alloc_1 alloc_2 ... alloc_n" + * where alloc_i looks like + * "offset size len name" + * or "offset size len name:line". + */ + + char token[64]; + unsigned long num_objects; + + if (!tokenize_frame_descr(&frame_descr, token, sizeof(token), + &num_objects)) + return; + + pr_err("\n"); + pr_err("this frame has %lu %s:\n", num_objects, + num_objects == 1 ? "object" : "objects"); + + while (num_objects--) { + unsigned long offset; + unsigned long size; + + /* access offset */ + if (!tokenize_frame_descr(&frame_descr, token, sizeof(token), + &offset)) + return; + /* access size */ + if (!tokenize_frame_descr(&frame_descr, token, sizeof(token), + &size)) + return; + /* name length (unused) */ + if (!tokenize_frame_descr(&frame_descr, NULL, 0, NULL)) + return; + /* object name */ + if (!tokenize_frame_descr(&frame_descr, token, sizeof(token), + NULL)) + return; + + /* Strip line number; without filename it's not very helpful. */ + strreplace(token, ':', '\0'); + + /* Finally, print object information. */ + pr_err(" [%lu, %lu) '%s'", offset, offset + size, token); + } +} + +static bool __must_check get_address_stack_frame_info(const void *addr, + unsigned long *offset, + const char **frame_descr, + const void **frame_pc) +{ + unsigned long aligned_addr; + unsigned long mem_ptr; + const u8 *shadow_bottom; + const u8 *shadow_ptr; + const unsigned long *frame; + + BUILD_BUG_ON(IS_ENABLED(CONFIG_STACK_GROWSUP)); + + /* + * NOTE: We currently only support printing frame information for + * accesses to the task's own stack. + */ + if (!object_is_on_stack(addr)) + return false; + + aligned_addr = round_down((unsigned long)addr, sizeof(long)); + mem_ptr = round_down(aligned_addr, KASAN_GRANULE_SIZE); + shadow_ptr = kasan_mem_to_shadow((void *)aligned_addr); + shadow_bottom = kasan_mem_to_shadow(end_of_stack(current)); + + while (shadow_ptr >= shadow_bottom && *shadow_ptr != KASAN_STACK_LEFT) { + shadow_ptr--; + mem_ptr -= KASAN_GRANULE_SIZE; + } + + while (shadow_ptr >= shadow_bottom && *shadow_ptr == KASAN_STACK_LEFT) { + shadow_ptr--; + mem_ptr -= KASAN_GRANULE_SIZE; + } + + if (shadow_ptr < shadow_bottom) + return false; + + frame = (const unsigned long *)(mem_ptr + KASAN_GRANULE_SIZE); + if (frame[0] != KASAN_CURRENT_STACK_FRAME_MAGIC) { + pr_err("KASAN internal error: frame info validation failed; invalid marker: %lu\n", + frame[0]); + return false; + } + + *offset = (unsigned long)addr - (unsigned long)frame; + *frame_descr = (const char *)frame[1]; + *frame_pc = (void *)frame[2]; + + return true; +} + +void print_address_stack_frame(const void *addr) +{ + unsigned long offset; + const char *frame_descr; + const void *frame_pc; + + if (!get_address_stack_frame_info(addr, &offset, &frame_descr, + &frame_pc)) + return; + + /* + * get_address_stack_frame_info only returns true if the given addr is + * on the current task's stack. + */ + pr_err("\n"); + pr_err("addr %px is located in stack of task %s/%d at offset %lu in frame:\n", + addr, current->comm, task_pid_nr(current), offset); + pr_err(" %pS\n", frame_pc); + + if (!frame_descr) + return; + + print_decoded_frame_descr(frame_descr); +} +#endif /* CONFIG_KASAN_STACK */ + #define DEFINE_ASAN_REPORT_LOAD(size) \ void __asan_report_load##size##_noabort(unsigned long addr) \ { \ _ Patches currently in -mm which might be from andreyknvl@xxxxxxxxxx are kasan-drop-unnecessary-gpl-text-from-comment-headers.patch kasan-kasan_vmalloc-depends-on-kasan_generic.patch kasan-group-vmalloc-code.patch kasan-shadow-declarations-only-for-software-modes.patch kasan-rename-unpoison_shadow-to-unpoison_range.patch kasan-rename-kasan_shadow_-to-kasan_granule_.patch kasan-only-build-initc-for-software-modes.patch kasan-split-out-shadowc-from-commonc.patch kasan-define-kasan_memory_per_shadow_page.patch kasan-rename-report-and-tags-files.patch kasan-dont-duplicate-config-dependencies.patch kasan-hide-invalid-free-check-implementation.patch kasan-decode-stack-frame-only-with-kasan_stack_enable.patch kasan-arm64-only-init-shadow-for-software-modes.patch kasan-arm64-only-use-kasan_depth-for-software-modes.patch kasan-arm64-move-initialization-message.patch kasan-arm64-rename-kasan_init_tags-and-mark-as-__init.patch kasan-rename-addr_has_shadow-to-addr_has_metadata.patch kasan-rename-print_shadow_for_address-to-print_memory_metadata.patch kasan-rename-shadow-layout-macros-to-meta.patch kasan-separate-metadata_fetch_row-for-each-mode.patch kasan-arm64-dont-allow-sw_tags-with-arm64_mte.patch kasan-introduce-config_kasan_hw_tags.patch arm64-kasan-align-allocations-for-hw_tags.patch arm64-kasan-add-arch-layer-for-memory-tagging-helpers.patch kasan-define-kasan_granule_size-for-hw_tags.patch kasan-x86-s390-update-undef-config_kasan.patch kasan-arm64-expand-config_kasan-checks.patch kasan-arm64-implement-hw_tags-runtime.patch kasan-arm64-print-report-from-tag-fault-handler.patch kasan-mm-reset-tags-when-accessing-metadata.patch kasan-arm64-enable-config_kasan_hw_tags.patch kasan-add-documentation-for-hardware-tag-based-mode.patch kasan-simplify-quarantine_put-call-site.patch kasan-rename-get_alloc-free_info.patch kasan-introduce-set_alloc_info.patch kasan-arm64-unpoison-stack-only-with-config_kasan_stack.patch kasan-allow-vmap_stack-for-hw_tags-mode.patch kasan-remove-__kasan_unpoison_stack.patch kasan-inline-kasan_reset_tag-for-tag-based-modes.patch kasan-inline-random_tag-for-hw_tags.patch kasan-open-code-kasan_unpoison_slab.patch kasan-inline-unpoison_range-and-check_invalid_free.patch kasan-add-and-integrate-kasan-boot-parameters.patch kasan-mm-check-kasan_enabled-in-annotations.patch kasan-mm-rename-kasan_poison_kfree.patch kasan-dont-round_up-too-much.patch kasan-simplify-assign_tag-and-set_tag-calls.patch kasan-clarify-comment-in-__kasan_kfree_large.patch kasan-sanitize-objects-when-metadata-doesnt-fit.patch kasan-mm-allow-cache-merging-with-no-metadata.patch kasan-update-documentation.patch