From: Andrey Konovalov <andreyknvl@xxxxxxxxxx> Subject: kasan: call print_report from kasan_report_invalid_free Call print_report() in kasan_report_invalid_free() instead of calling printing functions directly. Compared to the existing implementation of kasan_report_invalid_free(), print_report() makes sure that the buggy address has metadata before printing it. The change requires adding a report type field into kasan_access_info and using it accordingly. kasan_report_async() is left as is, as using print_report() will only complicate the code. Link: https://lkml.kernel.org/r/9ea6f0604c5d2e1fb28d93dc6c44232c1f8017fe.1646237226.git.andreyknvl@xxxxxxxxxx Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx> Cc: Alexander Potapenko <glider@xxxxxxxxxx> Cc: Andrey Ryabinin <ryabinin.a.a@xxxxxxxxx> Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx> Cc: Marco Elver <elver@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/kasan/kasan.h | 6 ++++++ mm/kasan/report.c | 42 ++++++++++++++++++++++++++---------------- 2 files changed, 32 insertions(+), 16 deletions(-) --- a/mm/kasan/kasan.h~kasan-call-print_report-from-kasan_report_invalid_free +++ a/mm/kasan/kasan.h @@ -127,7 +127,13 @@ static inline bool kasan_sync_fault_poss #define META_MEM_BYTES_PER_ROW (META_BYTES_PER_ROW * KASAN_GRANULE_SIZE) #define META_ROWS_AROUND_ADDR 2 +enum kasan_report_type { + KASAN_REPORT_ACCESS, + KASAN_REPORT_INVALID_FREE, +}; + struct kasan_access_info { + enum kasan_report_type type; void *access_addr; void *first_bad_addr; size_t access_size; --- a/mm/kasan/report.c~kasan-call-print_report-from-kasan_report_invalid_free +++ a/mm/kasan/report.c @@ -86,6 +86,12 @@ __setup("kasan_multi_shot", kasan_set_mu static void print_error_description(struct kasan_access_info *info) { + if (info->type == KASAN_REPORT_INVALID_FREE) { + pr_err("BUG: KASAN: double-free or invalid-free in %pS\n", + (void *)info->ip); + return; + } + pr_err("BUG: KASAN: %s in %pS\n", kasan_get_bug_type(info), (void *)info->ip); if (info->access_size) @@ -386,22 +392,6 @@ static bool report_enabled(void) return !test_and_set_bit(KASAN_BIT_REPORTED, &kasan_flags); } -void kasan_report_invalid_free(void *object, unsigned long ip) -{ - unsigned long flags; - u8 tag = get_tag(object); - - object = kasan_reset_tag(object); - - start_report(&flags, true); - pr_err("BUG: KASAN: double-free or invalid-free in %pS\n", (void *)ip); - kasan_print_tags(tag, object); - pr_err("\n"); - print_address_description(object, tag); - print_memory_metadata(object); - end_report(&flags, object); -} - #ifdef CONFIG_KASAN_HW_TAGS void kasan_report_async(void) { @@ -435,6 +425,25 @@ static void print_report(struct kasan_ac } } +void kasan_report_invalid_free(void *ptr, unsigned long ip) +{ + unsigned long flags; + struct kasan_access_info info; + + start_report(&flags, true); + + info.type = KASAN_REPORT_INVALID_FREE; + info.access_addr = ptr; + info.first_bad_addr = kasan_reset_tag(ptr); + info.access_size = 0; + info.is_write = false; + info.ip = ip; + + print_report(&info); + + end_report(&flags, ptr); +} + bool kasan_report(unsigned long addr, size_t size, bool is_write, unsigned long ip) { @@ -451,6 +460,7 @@ bool kasan_report(unsigned long addr, si start_report(&irq_flags, true); + info.type = KASAN_REPORT_ACCESS; info.access_addr = ptr; info.first_bad_addr = kasan_find_first_bad_addr(ptr, size); info.access_size = size; _
