• CVE-2021-47107

发布时间: 2024年5月27日

修改时间: 2025年2月15日

概要

In the Linux kernel, the following vulnerability has been resolved: NFSD: Fix READDIR buffer overflow If a client sends a READDIR count argument that is too small (say, zero), then the buffer size calculation in the new init_dirlist helper functions results in an underflow, allowing the XDR stream functions to write beyond the actual buffer. This calculation has always been suspect. NFSD has never sanity- checked the READDIR count argument, but the old entry encoders managed the problem correctly. With the commits below, entry encoding changed, exposing the underflow to the pointer arithmetic in xdr_reserve_space(). Modern NFS clients attempt to retrieve as much data as possible for each READDIR request. Also, we have no unit tests that exercise the behavior of READDIR at the lower bound of @count values. Thus this case was missed during testing.

CVSS v3 指标

NVD openEuler
Confidentiality High High
Attack Vector Local Local
CVSS评分 7.8 7.1
Attack Complexity Low Low
Privileges Required Low Low
Scope Unchanged Unchanged
Integrity High None
User Interaction None None
Availability High High

安全公告

公告名 概要 发布时间
KylinSec-SA-2024-1614 In the Linux kernel, the following vulnerability has been resolved: NFSD: Fix READDIR buffer overflow If a client sends a READDIR count argument that is too small (say, zero), then the buffer size calculation in the new init_dirlist helper functions results in an underflow, allowing the XDR stream functions to write beyond the actual buffer. This calculation has always been suspect. NFSD has never sanity- checked the READDIR count argument, but the old entry encoders managed the problem correctly. With the commits below, entry encoding changed, exposing the underflow to the pointer arithmetic in xdr_reserve_space(). Modern NFS clients attempt to retrieve as much data as possible for each READDIR request. Also, we have no unit tests that exercise the behavior of READDIR at the lower bound of @count values. Thus this case was missed during testing. 2024年5月27日

影响产品

产品 状态
KY3.4-4A kernel Unaffected
KY3.4-5 kernel Unaffected
KY3.5.1 kernel Unaffected
KY3.5.2 kernel Unaffected