Linux Kernel: __dst_negative_advice Race Enables UAF via RCU Violation
CVE-2024-36971 Published on June 10, 2024
net: fix __dst_negative_advice() race
In the Linux kernel, the following vulnerability has been resolved:
net: fix __dst_negative_advice() race
__dst_negative_advice() does not enforce proper RCU rules when
sk->dst_cache must be cleared, leading to possible UAF.
RCU rules are that we must first clear sk->sk_dst_cache,
then call dst_release(old_dst).
Note that sk_dst_reset(sk) is implementing this protocol correctly,
while __dst_negative_advice() uses the wrong order.
Given that ip6_negative_advice() has special logic
against RTF_CACHE, this means each of the three ->negative_advice()
existing methods must perform the sk_dst_reset() themselves.
Note the check against NULL dst is centralized in
__dst_negative_advice(), there is no need to duplicate
it in various callbacks.
Many thanks to Clement Lecigne for tracking this issue.
This old bug became visible after the blamed commit, using UDP sockets.
Known Exploited Vulnerability
This Android Kernel Remote Code Execution Vulnerability is part of CISA's list of Known Exploited Vulnerabilities. Android contains an unspecified vulnerability in the kernel that allows for remote code execution. This vulnerability resides in Linux Kernel and could impact other products, including but not limited to Android OS.
The following remediation steps are recommended / required by August 28, 2024: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
Vulnerability Analysis
CVE-2024-36971 can be exploited with local system access, and requires small amount of user privileges. This vulnerability is considered to have a low attack complexity. This vulnerability is known to be actively exploited by threat actors. The potential impact of an exploit of this vulnerability is considered to be very high.
Weakness Type
What is a Dangling pointer Vulnerability?
Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code.
CVE-2024-36971 has been classified to as a Dangling pointer vulnerability or weakness.
Products Associated with CVE-2024-36971
You can be notified by email with stack.watch whenever vulnerabilities like CVE-2024-36971 are published in these products:
Affected Versions
Linux:- Version a87cb3e48ee86d29868d3f59cfb9ce1a8fa63314 and below 051c0bde9f0450a2ec3d62a86d2a0d2fad117f13 is affected.
- Version a87cb3e48ee86d29868d3f59cfb9ce1a8fa63314 and below db0082825037794c5dba9959c9de13ca34cc5e72 is affected.
- Version a87cb3e48ee86d29868d3f59cfb9ce1a8fa63314 and below 2295a7ef5c8c49241bff769e7826ef2582e532a6 is affected.
- Version a87cb3e48ee86d29868d3f59cfb9ce1a8fa63314 and below eacb8b195579c174a6d3e12a9690b206eb7f28cf is affected.
- Version a87cb3e48ee86d29868d3f59cfb9ce1a8fa63314 and below 81dd3c82a456b0015461754be7cb2693991421b4 is affected.
- Version a87cb3e48ee86d29868d3f59cfb9ce1a8fa63314 and below 5af198c387128a9d2ddd620b0f0803564a4d4508 is affected.
- Version a87cb3e48ee86d29868d3f59cfb9ce1a8fa63314 and below b8af8e6118a6605f0e495a58d591ca94a85a50fc is affected.
- Version a87cb3e48ee86d29868d3f59cfb9ce1a8fa63314 and below 92f1655aa2b2294d0b49925f3b875a634bd3b59e is affected.
- Version 4.6 is affected.
- Before 4.6 is unaffected.
- Version 4.19.316, <= 4.19.* is unaffected.
- Version 5.4.278, <= 5.4.* is unaffected.
- Version 5.10.219, <= 5.10.* is unaffected.
- Version 5.15.161, <= 5.15.* is unaffected.
- Version 6.1.94, <= 6.1.* is unaffected.
- Version 6.6.34, <= 6.6.* is unaffected.
- Version 6.9.4, <= 6.9.* is unaffected.
- Version 6.10, <= * is unaffected.
- Version 4.6 is affected.
- Version a87cb3e48ee8 and below 051c0bde9f04 is affected.
- Version a87cb3e48ee8 and below db0082825037 is affected.
- Version a87cb3e48ee8 and below 2295a7ef5c8c is affected.
- Version a87cb3e48ee8 and below eacb8b195579 is affected.
- Version a87cb3e48ee8 and below 81dd3c82a456 is affected.
- Version a87cb3e48ee8 and below 5af198c38712 is affected.
- Version a87cb3e48ee8 and below b8af8e6118a6 is affected.
- Version a87cb3e48ee8 and below 92f1655aa2b2 is affected.
- Version a87cb3e48ee8 and below 051c0bde9f04 is affected.
- Version a87cb3e48ee8 and below db0082825037 is affected.
- Version a87cb3e48ee8 and below 2295a7ef5c8c is affected.
- Version a87cb3e48ee8 and below eacb8b195579 is affected.
- Version a87cb3e48ee8 and below 81dd3c82a456 is affected.
- Version a87cb3e48ee8 and below 5af198c38712 is affected.
- Version a87cb3e48ee8 and below b8af8e6118a6 is affected.
- Version a87cb3e48ee8 and below 92f1655aa2b2 is affected.
- Version a87cb3e48ee8 and below 051c0bde9f04 is affected.
- Version a87cb3e48ee8 and below db0082825037 is affected.
- Version a87cb3e48ee8 and below 2295a7ef5c8c is affected.
- Version a87cb3e48ee8 and below eacb8b195579 is affected.
- Version a87cb3e48ee8 and below 81dd3c82a456 is affected.
- Version a87cb3e48ee8 and below 5af198c38712 is affected.
- Version a87cb3e48ee8 and below b8af8e6118a6 is affected.
- Version a87cb3e48ee8 and below 92f1655aa2b2 is affected.
- Version a87cb3e48ee8 and below 051c0bde9f04 is affected.
- Version a87cb3e48ee8 and below db0082825037 is affected.
- Version a87cb3e48ee8 and below 2295a7ef5c8c is affected.
- Version a87cb3e48ee8 and below eacb8b195579 is affected.
- Version a87cb3e48ee8 and below 81dd3c82a456 is affected.
- Version a87cb3e48ee8 and below 5af198c38712 is affected.
- Version a87cb3e48ee8 and below b8af8e6118a6 is affected.
- Version a87cb3e48ee8 and below 92f1655aa2b2 is affected.
- Version a87cb3e48ee8 and below 051c0bde9f04 is affected.
- Version a87cb3e48ee8 and below db0082825037 is affected.
- Version a87cb3e48ee8 and below 2295a7ef5c8c is affected.
- Version a87cb3e48ee8 and below eacb8b195579 is affected.
- Version a87cb3e48ee8 and below 81dd3c82a456 is affected.
- Version a87cb3e48ee8 and below 5af198c38712 is affected.
- Version a87cb3e48ee8 and below b8af8e6118a6 is affected.
- Version a87cb3e48ee8 and below 92f1655aa2b2 is affected.
- Version a87cb3e48ee8 and below 051c0bde9f04 is affected.
- Version a87cb3e48ee8 and below db0082825037 is affected.
- Version a87cb3e48ee8 and below 2295a7ef5c8c is affected.
- Version a87cb3e48ee8 and below eacb8b195579 is affected.
- Version a87cb3e48ee8 and below 81dd3c82a456 is affected.
- Version a87cb3e48ee8 and below 5af198c38712 is affected.
- Version a87cb3e48ee8 and below b8af8e6118a6 is affected.
- Version a87cb3e48ee8 and below 92f1655aa2b2 is affected.
- Version a87cb3e48ee8 and below 051c0bde9f04 is affected.
- Version a87cb3e48ee8 and below db0082825037 is affected.
- Version a87cb3e48ee8 and below 2295a7ef5c8c is affected.
- Version a87cb3e48ee8 and below eacb8b195579 is affected.
- Version a87cb3e48ee8 and below 81dd3c82a456 is affected.
- Version a87cb3e48ee8 and below 5af198c38712 is affected.
- Version a87cb3e48ee8 and below b8af8e6118a6 is affected.
- Version a87cb3e48ee8 and below 92f1655aa2b2 is affected.
- Version a87cb3e48ee8 and below 051c0bde9f04 is affected.
- Version a87cb3e48ee8 and below db0082825037 is affected.
- Version a87cb3e48ee8 and below 2295a7ef5c8c is affected.
- Version a87cb3e48ee8 and below eacb8b195579 is affected.
- Version a87cb3e48ee8 and below 81dd3c82a456 is affected.
- Version a87cb3e48ee8 and below 5af198c38712 is affected.
- Version a87cb3e48ee8 and below b8af8e6118a6 is affected.
- Version a87cb3e48ee8 and below 92f1655aa2b2 is affected.
- Before 4.6 is unaffected.
- Version 4.19.316 and below 4.20 is unaffected.
- Version 5.4.278 and below 5.5 is unaffected.
- Version 5.10.219 and below 5.11 is unaffected.
- Version 5.15.161 and below 5.16 is unaffected.
- Version 6.1.94 and below 6.2 is unaffected.
- Version 6.6.34 and below 6.7 is unaffected.
- Version 6.9.4 and below 6.10 is unaffected.
- Version 6.10, <= * is unaffected.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.