diff options
Diffstat (limited to 'mm/kasan/report.c')
| -rw-r--r-- | mm/kasan/report.c | 44 |
1 files changed, 32 insertions, 12 deletions
diff --git a/mm/kasan/report.c b/mm/kasan/report.c index 892a9dc9d4d3..ca4b6ff080a6 100644 --- a/mm/kasan/report.c +++ b/mm/kasan/report.c @@ -43,6 +43,7 @@ enum kasan_arg_fault { KASAN_ARG_FAULT_DEFAULT, KASAN_ARG_FAULT_REPORT, KASAN_ARG_FAULT_PANIC, + KASAN_ARG_FAULT_PANIC_ON_WRITE, }; static enum kasan_arg_fault kasan_arg_fault __ro_after_init = KASAN_ARG_FAULT_DEFAULT; @@ -57,6 +58,8 @@ static int __init early_kasan_fault(char *arg) kasan_arg_fault = KASAN_ARG_FAULT_REPORT; else if (!strcmp(arg, "panic")) kasan_arg_fault = KASAN_ARG_FAULT_PANIC; + else if (!strcmp(arg, "panic_on_write")) + kasan_arg_fault = KASAN_ARG_FAULT_PANIC_ON_WRITE; else return -EINVAL; @@ -211,7 +214,7 @@ static void start_report(unsigned long *flags, bool sync) pr_err("==================================================================\n"); } -static void end_report(unsigned long *flags, void *addr) +static void end_report(unsigned long *flags, const void *addr, bool is_write) { if (addr) trace_error_report_end(ERROR_DETECTOR_KASAN, @@ -220,8 +223,18 @@ static void end_report(unsigned long *flags, void *addr) spin_unlock_irqrestore(&report_lock, *flags); if (!test_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags)) check_panic_on_warn("KASAN"); - if (kasan_arg_fault == KASAN_ARG_FAULT_PANIC) + switch (kasan_arg_fault) { + case KASAN_ARG_FAULT_DEFAULT: + case KASAN_ARG_FAULT_REPORT: + break; + case KASAN_ARG_FAULT_PANIC: panic("kasan.fault=panic set ...\n"); + break; + case KASAN_ARG_FAULT_PANIC_ON_WRITE: + if (is_write) + panic("kasan.fault=panic_on_write set ...\n"); + break; + } add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE); lockdep_on(); report_suppress_stop(); @@ -450,8 +463,8 @@ static void print_memory_metadata(const void *addr) static void print_report(struct kasan_report_info *info) { - void *addr = kasan_reset_tag(info->access_addr); - u8 tag = get_tag(info->access_addr); + void *addr = kasan_reset_tag((void *)info->access_addr); + u8 tag = get_tag((void *)info->access_addr); print_error_description(info); if (addr_has_metadata(addr)) @@ -468,12 +481,12 @@ static void print_report(struct kasan_report_info *info) static void complete_report_info(struct kasan_report_info *info) { - void *addr = kasan_reset_tag(info->access_addr); + void *addr = kasan_reset_tag((void *)info->access_addr); struct slab *slab; if (info->type == KASAN_REPORT_ACCESS) info->first_bad_addr = kasan_find_first_bad_addr( - info->access_addr, info->access_size); + (void *)info->access_addr, info->access_size); else info->first_bad_addr = addr; @@ -536,7 +549,11 @@ void kasan_report_invalid_free(void *ptr, unsigned long ip, enum kasan_report_ty print_report(&info); - end_report(&flags, ptr); + /* + * Invalid free is considered a "write" since the allocator's metadata + * updates involves writes. + */ + end_report(&flags, ptr, true); } /* @@ -544,11 +561,10 @@ void kasan_report_invalid_free(void *ptr, unsigned long ip, enum kasan_report_ty * user_access_save/restore(): kasan_report_invalid_free() cannot be called * from a UACCESS region, and kasan_report_async() is not used on x86. */ -bool kasan_report(unsigned long addr, size_t size, bool is_write, +bool kasan_report(const void *addr, size_t size, bool is_write, unsigned long ip) { bool ret = true; - void *ptr = (void *)addr; unsigned long ua_flags = user_access_save(); unsigned long irq_flags; struct kasan_report_info info; @@ -562,7 +578,7 @@ bool kasan_report(unsigned long addr, size_t size, bool is_write, memset(&info, 0, sizeof(info)); info.type = KASAN_REPORT_ACCESS; - info.access_addr = ptr; + info.access_addr = addr; info.access_size = size; info.is_write = is_write; info.ip = ip; @@ -571,7 +587,7 @@ bool kasan_report(unsigned long addr, size_t size, bool is_write, print_report(&info); - end_report(&irq_flags, ptr); + end_report(&irq_flags, (void *)addr, is_write); out: user_access_restore(ua_flags); @@ -597,7 +613,11 @@ void kasan_report_async(void) pr_err("Asynchronous fault: no details available\n"); pr_err("\n"); dump_stack_lvl(KERN_ERR); - end_report(&flags, NULL); + /* + * Conservatively set is_write=true, because no details are available. + * In this mode, kasan.fault=panic_on_write is like kasan.fault=panic. + */ + end_report(&flags, NULL, true); } #endif /* CONFIG_KASAN_HW_TAGS */ |