Android · Kernel
CVE-2024-36971
net: fix __dst_negative_advice() race
What it is
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.
CISA: 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.
What to do
Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
Deadline for US federal agencies: August 28, 2024
- Added to the CISA list
- August 7, 2024
- Published
- June 10, 2024
- Severity
- High 7.8 CVSS 3.1
- Chance of attacks in the next 30 days (EPSS)
- 2.7% in the top 14.1% of all known vulnerabilities
- Weakness
- CWE-416
- More details
- NVD · CVE.org · CISA
All references (8)
- https://git.kernel.org/stable/c/051c0bde9f0450a2ec3d62a86d2a0d2fad117f13
- https://git.kernel.org/stable/c/db0082825037794c5dba9959c9de13ca34cc5e72
- https://git.kernel.org/stable/c/2295a7ef5c8c49241bff769e7826ef2582e532a6
- https://git.kernel.org/stable/c/eacb8b195579c174a6d3e12a9690b206eb7f28cf
- https://git.kernel.org/stable/c/81dd3c82a456b0015461754be7cb2693991421b4
- https://git.kernel.org/stable/c/5af198c387128a9d2ddd620b0f0803564a4d4508
- https://git.kernel.org/stable/c/b8af8e6118a6605f0e495a58d591ca94a85a50fc
- https://git.kernel.org/stable/c/92f1655aa2b2294d0b49925f3b875a634bd3b59e
More exploited flaws from Android
| Added | Vulnerability | Product | Severity | Attack chance |
|---|---|---|---|---|
| May 23, 2022 | Race Condition | Kernel | Medium 6.4 | 0.9% |
| May 23, 2022 | Use-After-Free | Kernel | High 7.8 | 1.1% |
| Jun 2, 2026 | Integer Overflow | Framework | High 8.4 | 1.9% |
| Dec 2, 2025 | Privilege Escalation | Framework | High 7.8 | 0.3% |
| Dec 2, 2025 | Information Disclosure | Framework | Medium 5.5 | 0.3% |
| Sep 4, 2025 | Use-After-Free | Runtime | High 8.8 | 0.6% |
| Nov 7, 2024 | Privilege Escalation | Framework | High 7.3 | 0.7% |
| Jun 13, 2024 | Privilege Escalation | Pixel | High 8.1 | 3.0% |
Sources: Known Exploited Vulnerabilities (CISA, public domain), CVE records (cve.org) and EPSS (FIRST). The chance of attacks is the EPSS estimate that someone will try to exploit the flaw in the next 30 days.