Commit 31c65110 authored by Andrey Konovalov's avatar Andrey Konovalov Committed by Linus Torvalds
Browse files

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@google.com


Signed-off-by: default avatarAndrey Konovalov <andreyknvl@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Marco Elver <elver@google.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent be8631a1

mm/kasan/kasan.h

+6 −0
Original line number Diff line number Diff line
@@ -127,7 +127,13 @@ static inline bool kasan_sync_fault_possible(void) 
#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;

mm/kasan/report.c

+26 −16
Original line number Diff line number Diff line
@@ -86,6 +86,12 @@ __setup("kasan_multi_shot", kasan_set_multi_shot); 


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_access_info *info) 
	}

}



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, size_t size, bool is_write, 


	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;