net/tls:修复 TLS 设备关闭和启动后的释放后使用 (CVE-2021-47131)
CVE编号
CVE-2021-47131利用情况
暂无补丁情况
N/A披露时间
2024-03-16漏洞描述
In the Linux kernel, the following vulnerability has been resolved: net/tls: Fix use-after-free after the TLS device goes down and up When a netdev with active TLS offload goes down, tls_device_down is called to stop the offload and tear down the TLS context. However, the socket stays alive, and it still points to the TLS context, which is now deallocated. If a netdev goes up, while the connection is still active, and the data flow resumes after a number of TCP retransmissions, it will lead to a use-after-free of the TLS context. This commit addresses this bug by keeping the context alive until its normal destruction, and implements the necessary fallbacks, so that the connection can resume in software (non-offloaded) kTLS mode. On the TX side tls_sw_fallback is used to encrypt all packets. The RX side already has all the necessary fallbacks, because receiving non-decrypted packets is supported. The thing needed on the RX side is to block resync requests, which are normally produced after receiving non-decrypted packets. The necessary synchronization is implemented for a graceful teardown: first the fallbacks are deployed, then the driver resources are released (it used to be possible to have a tls_dev_resync after tls_dev_del). A new flag called TLS_RX_DEV_DEGRADED is added to indicate the fallback mode. It's used to skip the RX resync logic completely, as it becomes useless, and some objects may be released (for example, resync_async, which is allocated and freed by the driver).解决建议
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# | 类型 | 厂商 | 产品 | 版本 | 影响面 | ||||
1 | |||||||||
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运行在以下环境 | |||||||||
系统 | debian_11 | linux | * | Up to (excluding) 5.10.46-1 | |||||
运行在以下环境 | |||||||||
系统 | debian_12 | linux | * | Up to (excluding) 5.10.46-1 |
- 攻击路径 N/A
- 攻击复杂度 N/A
- 权限要求 N/A
- 影响范围 N/A
- 用户交互 N/A
- 可用性 N/A
- 保密性 N/A
- 完整性 N/A
CWE-ID | 漏洞类型 |
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