中危 binder:修复 shinker 回调中的释放后使用 (CVE-2023-52438)

CVE编号

CVE-2023-52438

利用情况

暂无

补丁情况

官方补丁

披露时间

2024-02-21
漏洞描述
In the Linux kernel, the following vulnerability has been resolved:

binder: fix use-after-free in shinker's callback

The mmap read lock is used during the shrinker's callback, which means
that using alloc->vma pointer isn't safe as it can race with munmap().
As of commit dd2283f2605e ("mm: mmap: zap pages with read mmap_sem in
munmap") the mmap lock is downgraded after the vma has been isolated.

I was able to reproduce this issue by manually adding some delays and
triggering page reclaiming through the shrinker's debug sysfs. The
following KASAN report confirms the UAF:

==================================================================
BUG: KASAN: slab-use-after-free in zap_page_range_single+0x470/0x4b8
Read of size 8 at addr ffff356ed50e50f0 by task bash/478

CPU: 1 PID: 478 Comm: bash Not tainted 6.6.0-rc5-00055-g1c8b86a3799f-dirty #70
Hardware name: linux,dummy-virt (DT)
Call trace:
zap_page_range_single+0x470/0x4b8
binder_alloc_free_page+0x608/0xadc
__list_lru_walk_one+0x130/0x3b0
list_lru_walk_node+0xc4/0x22c
binder_shrink_scan+0x108/0x1dc
shrinker_debugfs_scan_write+0x2b4/0x500
full_proxy_write+0xd4/0x140
vfs_write+0x1ac/0x758
ksys_write+0xf0/0x1dc
__arm64_sys_write+0x6c/0x9c

Allocated by task 492:
kmem_cache_alloc+0x130/0x368
vm_area_alloc+0x2c/0x190
mmap_region+0x258/0x18bc
do_mmap+0x694/0xa60
vm_mmap_pgoff+0x170/0x29c
ksys_mmap_pgoff+0x290/0x3a0
__arm64_sys_mmap+0xcc/0x144

Freed by task 491:
kmem_cache_free+0x17c/0x3c8
vm_area_free_rcu_cb+0x74/0x98
rcu_core+0xa38/0x26d4
rcu_core_si+0x10/0x1c
__do_softirq+0x2fc/0xd24

Last potentially related work creation:
__call_rcu_common.constprop.0+0x6c/0xba0
call_rcu+0x10/0x1c
vm_area_free+0x18/0x24
remove_vma+0xe4/0x118
do_vmi_align_munmap.isra.0+0x718/0xb5c
do_vmi_munmap+0xdc/0x1fc
__vm_munmap+0x10c/0x278
__arm64_sys_munmap+0x58/0x7c

Fix this issue by performing instead a vma_lookup() which will fail to
find the vma that was isolated before the mmap lock downgrade. Note that
this option has better performance than upgrading to a mmap write lock
which would increase contention. Plus, mmap_write_trylock() has been
recently removed anyway.
解决建议
建议您更新当前系统或软件至最新版,完成漏洞的修复。
受影响软件情况
# 类型 厂商 产品 版本 影响面
1
运行在以下环境
系统 debian_10 linux * Up to
(excluding)
4.19.304-1
运行在以下环境
系统 debian_11 linux * Up to
(excluding)
5.10.209-1
运行在以下环境
系统 debian_12 linux * Up to
(excluding)
6.1.76-1
运行在以下环境
系统 linux linux_kernel * From
(including)
4.20.0
Up to
(excluding)
5.4.268
运行在以下环境
系统 linux linux_kernel * From
(including)
5.11.0
Up to
(excluding)
5.15.148
运行在以下环境
系统 linux linux_kernel * From
(including)
5.16.0
Up to
(excluding)
6.1.74
运行在以下环境
系统 linux linux_kernel * From
(including)
5.5.0
Up to
(excluding)
5.10.209
运行在以下环境
系统 linux linux_kernel * From
(including)
6.2.0
Up to
(excluding)
6.6.13
运行在以下环境
系统 linux linux_kernel * From
(including)
6.7.0
Up to
(excluding)
6.7.1
阿里云评分
6.5
  • 攻击路径
    本地
  • 攻击复杂度
    复杂
  • 权限要求
    普通权限
  • 影响范围
    越权影响
  • EXP成熟度
    未验证
  • 补丁情况
    官方补丁
  • 数据保密性
    无影响
  • 数据完整性
    无影响
  • 服务器危害
    无影响
  • 全网数量
    N/A
CWE-ID 漏洞类型
CWE-416 释放后使用
阿里云安全产品覆盖情况