Commit a31d890e authored by Kent Overstreet's avatar Kent Overstreet Committed by Zhao Wenhui
Browse files

lib/generic-radix-tree.c: Don't overflow in peek() 

mainline inclusion
from mainline-v6.7-rc1
commit 9492261ff2460252cf2d8de89cdf854c7e2b28a0
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9R4NX
CVE: CVE-2021-47432

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=9492261ff2460252cf2d8de89cdf854c7e2b28a0



--------------------------------

When we started spreading new inode numbers throughout most of the 64
bit inode space, that triggered some corner case bugs, in particular
some integer overflows related to the radix tree code. Oops.

Conflicts:
	include/linux/generic-radix-tree.h
[head file differents.]
Signed-off-by: default avatarKent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: default avatarZhao Wenhui <zhaowenhui8@huawei.com>
parent 9bb937dc

include/linux/generic-radix-tree.h

+7 −0
Original line number Diff line number Diff line
@@ -39,6 +39,7 @@ 
#include <asm/page.h>

#include <linux/bug.h>

#include <linux/kernel.h>

#include <linux/limits.h>

#include <linux/log2.h>



struct genradix_root;
@@ -183,6 +184,12 @@ void *__genradix_iter_peek(struct genradix_iter *, struct __genradix *, size_t); 
static inline void __genradix_iter_advance(struct genradix_iter *iter,

					   size_t obj_size)

{

	if (iter->offset + obj_size < iter->offset) {

		iter->offset	= SIZE_MAX;

		iter->pos	= SIZE_MAX;

		return;

	}



	iter->offset += obj_size;



	if (!is_power_of_2(obj_size) &&

lib/generic-radix-tree.c

+14 −3
Original line number Diff line number Diff line
@@ -166,6 +166,10 @@ void *__genradix_iter_peek(struct genradix_iter *iter, 
	struct genradix_root *r;

	struct genradix_node *n;

	unsigned level, i;



	if (iter->offset == SIZE_MAX)

		return NULL;



restart:

	r = READ_ONCE(radix->root);

	if (!r)
@@ -184,10 +188,17 @@ void *__genradix_iter_peek(struct genradix_iter *iter, 
			(GENRADIX_ARY - 1);



		while (!n->children[i]) {

			size_t objs_per_ptr = genradix_depth_size(level);



			if (iter->offset + objs_per_ptr < iter->offset) {

				iter->offset	= SIZE_MAX;

				iter->pos	= SIZE_MAX;

				return NULL;

			}



			i++;

			iter->offset = round_down(iter->offset +

					   genradix_depth_size(level),

					   genradix_depth_size(level));

			iter->offset = round_down(iter->offset + objs_per_ptr,

						  objs_per_ptr);

			iter->pos = (iter->offset >> PAGE_SHIFT) *

				objs_per_page;

			if (i == GENRADIX_ARY)