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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
commitace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch)
treeb2d64bc10158fdd5497876388cd68142ca374ed3 /mm/kasan/report_generic.c
parentInitial commit. (diff)
downloadlinux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz
linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'mm/kasan/report_generic.c')
-rw-r--r--mm/kasan/report_generic.c399
1 files changed, 399 insertions, 0 deletions
diff --git a/mm/kasan/report_generic.c b/mm/kasan/report_generic.c
new file mode 100644
index 0000000000..51a1e8a887
--- /dev/null
+++ b/mm/kasan/report_generic.c
@@ -0,0 +1,399 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * This file contains generic KASAN specific error reporting code.
+ *
+ * Copyright (c) 2014 Samsung Electronics Co., Ltd.
+ * Author: Andrey Ryabinin <ryabinin.a.a@gmail.com>
+ *
+ * Some code borrowed from https://github.com/xairy/kasan-prototype by
+ * Andrey Konovalov <andreyknvl@gmail.com>
+ */
+
+#include <linux/bitops.h>
+#include <linux/ftrace.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#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>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/kasan.h>
+#include <linux/module.h>
+
+#include <asm/sections.h>
+
+#include "kasan.h"
+#include "../slab.h"
+
+const void *kasan_find_first_bad_addr(const void *addr, size_t size)
+{
+ const void *p = addr;
+
+ if (!addr_has_metadata(p))
+ return p;
+
+ while (p < addr + size && !(*(u8 *)kasan_mem_to_shadow(p)))
+ p += KASAN_GRANULE_SIZE;
+
+ return p;
+}
+
+size_t kasan_get_alloc_size(void *object, struct kmem_cache *cache)
+{
+ size_t size = 0;
+ u8 *shadow;
+
+ /*
+ * Skip the addr_has_metadata check, as this function only operates on
+ * slab memory, which must have metadata.
+ */
+
+ /*
+ * The loop below returns 0 for freed objects, for which KASAN cannot
+ * calculate the allocation size based on the metadata.
+ */
+ shadow = (u8 *)kasan_mem_to_shadow(object);
+ while (size < cache->object_size) {
+ if (*shadow == 0)
+ size += KASAN_GRANULE_SIZE;
+ else if (*shadow >= 1 && *shadow <= KASAN_GRANULE_SIZE - 1)
+ return size + *shadow;
+ else
+ return size;
+ shadow++;
+ }
+
+ return cache->object_size;
+}
+
+static const char *get_shadow_bug_type(struct kasan_report_info *info)
+{
+ const char *bug_type = "unknown-crash";
+ u8 *shadow_addr;
+
+ shadow_addr = (u8 *)kasan_mem_to_shadow(info->first_bad_addr);
+
+ /*
+ * If shadow byte value is in [0, KASAN_GRANULE_SIZE) we can look
+ * at the next shadow byte to determine the type of the bad access.
+ */
+ if (*shadow_addr > 0 && *shadow_addr <= KASAN_GRANULE_SIZE - 1)
+ shadow_addr++;
+
+ switch (*shadow_addr) {
+ case 0 ... KASAN_GRANULE_SIZE - 1:
+ /*
+ * In theory it's still possible to see these shadow values
+ * due to a data race in the kernel code.
+ */
+ bug_type = "out-of-bounds";
+ break;
+ case KASAN_PAGE_REDZONE:
+ case KASAN_SLAB_REDZONE:
+ bug_type = "slab-out-of-bounds";
+ break;
+ case KASAN_GLOBAL_REDZONE:
+ bug_type = "global-out-of-bounds";
+ break;
+ case KASAN_STACK_LEFT:
+ case KASAN_STACK_MID:
+ case KASAN_STACK_RIGHT:
+ case KASAN_STACK_PARTIAL:
+ bug_type = "stack-out-of-bounds";
+ break;
+ case KASAN_PAGE_FREE:
+ bug_type = "use-after-free";
+ break;
+ case KASAN_SLAB_FREE:
+ case KASAN_SLAB_FREETRACK:
+ bug_type = "slab-use-after-free";
+ break;
+ case KASAN_ALLOCA_LEFT:
+ case KASAN_ALLOCA_RIGHT:
+ bug_type = "alloca-out-of-bounds";
+ break;
+ case KASAN_VMALLOC_INVALID:
+ bug_type = "vmalloc-out-of-bounds";
+ break;
+ }
+
+ return bug_type;
+}
+
+static const char *get_wild_bug_type(struct kasan_report_info *info)
+{
+ const char *bug_type = "unknown-crash";
+
+ if ((unsigned long)info->access_addr < PAGE_SIZE)
+ bug_type = "null-ptr-deref";
+ else if ((unsigned long)info->access_addr < TASK_SIZE)
+ bug_type = "user-memory-access";
+ else
+ bug_type = "wild-memory-access";
+
+ return bug_type;
+}
+
+static const char *get_bug_type(struct kasan_report_info *info)
+{
+ /*
+ * If access_size is a negative number, then it has reason to be
+ * defined as out-of-bounds bug type.
+ *
+ * Casting negative numbers to size_t would indeed turn up as
+ * a large size_t and its value will be larger than ULONG_MAX/2,
+ * so that this can qualify as out-of-bounds.
+ */
+ if (info->access_addr + info->access_size < info->access_addr)
+ return "out-of-bounds";
+
+ if (addr_has_metadata(info->access_addr))
+ return get_shadow_bug_type(info);
+ return get_wild_bug_type(info);
+}
+
+void kasan_complete_mode_report_info(struct kasan_report_info *info)
+{
+ struct kasan_alloc_meta *alloc_meta;
+ struct kasan_free_meta *free_meta;
+
+ if (!info->bug_type)
+ info->bug_type = get_bug_type(info);
+
+ if (!info->cache || !info->object)
+ return;
+
+ alloc_meta = kasan_get_alloc_meta(info->cache, info->object);
+ if (alloc_meta)
+ memcpy(&info->alloc_track, &alloc_meta->alloc_track,
+ sizeof(info->alloc_track));
+
+ if (*(u8 *)kasan_mem_to_shadow(info->object) == KASAN_SLAB_FREETRACK) {
+ /* Free meta must be present with KASAN_SLAB_FREETRACK. */
+ free_meta = kasan_get_free_meta(info->cache, info->object);
+ memcpy(&info->free_track, &free_meta->free_track,
+ sizeof(info->free_track));
+ }
+}
+
+void kasan_metadata_fetch_row(char *buffer, void *row)
+{
+ memcpy(buffer, kasan_mem_to_shadow(row), META_BYTES_PER_ROW);
+}
+
+void kasan_print_aux_stacks(struct kmem_cache *cache, const void *object)
+{
+ struct kasan_alloc_meta *alloc_meta;
+
+ alloc_meta = kasan_get_alloc_meta(cache, object);
+ if (!alloc_meta)
+ return;
+
+ if (alloc_meta->aux_stack[0]) {
+ pr_err("Last potentially related work creation:\n");
+ stack_depot_print(alloc_meta->aux_stack[0]);
+ pr_err("\n");
+ }
+ if (alloc_meta->aux_stack[1]) {
+ pr_err("Second to last potentially related work creation:\n");
+ stack_depot_print(alloc_meta->aux_stack[1]);
+ pr_err("\n");
+ }
+}
+
+#ifdef 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'). */
+ strscpy(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);
+ }
+}
+
+/* Returns true only if the address is on the current task's stack. */
+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));
+
+ 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 kasan_print_address_stack_frame(const void *addr)
+{
+ unsigned long offset;
+ const char *frame_descr;
+ const void *frame_pc;
+
+ if (WARN_ON(!object_is_on_stack(addr)))
+ return;
+
+ pr_err("The buggy address belongs to stack of task %s/%d\n",
+ current->comm, task_pid_nr(current));
+
+ if (!get_address_stack_frame_info(addr, &offset, &frame_descr,
+ &frame_pc))
+ return;
+
+ pr_err(" and is located at offset %lu in frame:\n", 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(void *addr) \
+{ \
+ kasan_report(addr, size, false, _RET_IP_); \
+} \
+EXPORT_SYMBOL(__asan_report_load##size##_noabort)
+
+#define DEFINE_ASAN_REPORT_STORE(size) \
+void __asan_report_store##size##_noabort(void *addr) \
+{ \
+ kasan_report(addr, size, true, _RET_IP_); \
+} \
+EXPORT_SYMBOL(__asan_report_store##size##_noabort)
+
+DEFINE_ASAN_REPORT_LOAD(1);
+DEFINE_ASAN_REPORT_LOAD(2);
+DEFINE_ASAN_REPORT_LOAD(4);
+DEFINE_ASAN_REPORT_LOAD(8);
+DEFINE_ASAN_REPORT_LOAD(16);
+DEFINE_ASAN_REPORT_STORE(1);
+DEFINE_ASAN_REPORT_STORE(2);
+DEFINE_ASAN_REPORT_STORE(4);
+DEFINE_ASAN_REPORT_STORE(8);
+DEFINE_ASAN_REPORT_STORE(16);
+
+void __asan_report_load_n_noabort(void *addr, ssize_t size)
+{
+ kasan_report(addr, size, false, _RET_IP_);
+}
+EXPORT_SYMBOL(__asan_report_load_n_noabort);
+
+void __asan_report_store_n_noabort(void *addr, ssize_t size)
+{
+ kasan_report(addr, size, true, _RET_IP_);
+}
+EXPORT_SYMBOL(__asan_report_store_n_noabort);