mm/kasan/report_generic.c - SHIFTPHONES/kernel/common - Gitiles

 // 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"

 void *kasan_find_first_bad_addr(void *addr, size_t size)
 {
 	void *p = addr;

 	while (p < addr + size && !(*(u8 *)kasan_mem_to_shadow(p)))
 		p += KASAN_GRANULE_SIZE;
 	return p;
 }

 static const char *get_shadow_bug_type(struct kasan_access_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_KMALLOC_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_FREE_PAGE:
 	case KASAN_KMALLOC_FREE:
 	case KASAN_KMALLOC_FREETRACK:
 		bug_type = "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_access_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;
 }

 const char *kasan_get_bug_type(struct kasan_access_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_metadata_fetch_row(char *buffer, void *row)
 {
 	memcpy(buffer, kasan_mem_to_shadow(row), META_BYTES_PER_ROW);
 }

 #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'). */
 		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 kasan_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) \
 {                                                         \
 	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(unsigned long 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(unsigned long addr, size_t size)
 {
 	kasan_report(addr, size, false, _RET_IP_);
 }
 EXPORT_SYMBOL(__asan_report_load_n_noabort);

 void __asan_report_store_n_noabort(unsigned long addr, size_t size)
 {
 	kasan_report(addr, size, true, _RET_IP_);
 }
 EXPORT_SYMBOL(__asan_report_store_n_noabort);
	// 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"

	void kasan_find_first_bad_addr(void addr, size_t size)
	{
	void *p = addr;

	while (p < addr + size && !((u8 )kasan_mem_to_shadow(p)))
	p += KASAN_GRANULE_SIZE;
	return p;
	}

	static const char get_shadow_bug_type(struct kasan_access_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_KMALLOC_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_FREE_PAGE:
	case KASAN_KMALLOC_FREE:
	case KASAN_KMALLOC_FREETRACK:
	bug_type = "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_access_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;
	}

	const char kasan_get_bug_type(struct kasan_access_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_metadata_fetch_row(char buffer, void row)
	{
	memcpy(buffer, kasan_mem_to_shadow(row), META_BYTES_PER_ROW);
	}

	#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'). */
	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 kasan_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) \
	{ \
	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(unsigned long 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(unsigned long addr, size_t size)
	{
	kasan_report(addr, size, false, _RET_IP_);
	}
	EXPORT_SYMBOL(__asan_report_load_n_noabort);

	void __asan_report_store_n_noabort(unsigned long addr, size_t size)
	{
	kasan_report(addr, size, true, _RET_IP_);
	}
	EXPORT_SYMBOL(__asan_report_store_n_noabort);