From d704c3fc310fac21d59a27ee7cb403cfaa4c4d3a Mon Sep 17 00:00:00 2001
From: Kent Overstreet <kent.overstreet@gmail.com>
Date: Tue, 16 Jul 2024 12:15:28 +0000
Subject: [PATCH] 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: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Zhao Wenhui <zhaowenhui8@huawei.com>
---
 include/linux/generic-radix-tree.h |  7 +++++++
 lib/generic-radix-tree.c           | 17 ++++++++++++++---
 2 files changed, 21 insertions(+), 3 deletions(-)

diff --git a/include/linux/generic-radix-tree.h b/include/linux/generic-radix-tree.h
index bfd00320c7f3..0e7abc635e5f 100644
--- a/include/linux/generic-radix-tree.h
+++ b/include/linux/generic-radix-tree.h
@@ -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) &&
diff --git a/lib/generic-radix-tree.c b/lib/generic-radix-tree.c
index f25eb111c051..7dfa88282b00 100644
--- a/lib/generic-radix-tree.c
+++ b/lib/generic-radix-tree.c
@@ -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)
-- 
Gitee