CVE-2023-52504

x86/alternatives: Disable KASAN in apply_alternatives()

Description

In the Linux kernel, the following vulnerability has been resolved: x86/alternatives: Disable KASAN in apply_alternatives() Fei has reported that KASAN triggers during apply_alternatives() on a 5-level paging machine: BUG: KASAN: out-of-bounds in rcu_is_watching() Read of size 4 at addr ff110003ee6419a0 by task swapper/0/0 ... __asan_load4() rcu_is_watching() trace_hardirqs_on() text_poke_early() apply_alternatives() ... On machines with 5-level paging, cpu_feature_enabled(X86_FEATURE_LA57) gets patched. It includes KASAN code, where KASAN_SHADOW_START depends on __VIRTUAL_MASK_SHIFT, which is defined with cpu_feature_enabled(). KASAN gets confused when apply_alternatives() patches the KASAN_SHADOW_START users. A test patch that makes KASAN_SHADOW_START static, by replacing __VIRTUAL_MASK_SHIFT with 56, works around the issue. Fix it for real by disabling KASAN while the kernel is patching alternatives. [ mingo: updated the changelog ]

Category

7.1
CVSS
Severity: High
CVSS 3.1 •
EPSS 0.01%
Affected: Linux Linux
Affected: Linux Linux
Published at:
Updated at:

References

Link Tags
https://git.kernel.org/stable/c/3719d3c36aa853d5a2401af9f8d6b116c91ad5ae patch
https://git.kernel.org/stable/c/3770c38cd6a60494da29ac2da73ff8156440a2d1 patch
https://git.kernel.org/stable/c/6788b10620ca6e98575d1e06e72a8974aad7657e patch
https://git.kernel.org/stable/c/ecba5afe86f30605eb9dfb7f265a8de0218d4cfc patch
https://git.kernel.org/stable/c/5b784489c8158518bf7a466bb3cc045b0fb66b4b patch
https://git.kernel.org/stable/c/cd287cc208dfe6bd6da98e7f88e723209242c9b4 patch
https://git.kernel.org/stable/c/d35652a5fc9944784f6f50a5c979518ff8dacf61 patch

Frequently Asked Questions

What is the severity of CVE-2023-52504?
CVE-2023-52504 has been scored as a high severity vulnerability.
How to fix CVE-2023-52504?
To fix CVE-2023-52504, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2023-52504 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2023-52504 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2023-52504?
CVE-2023-52504 affects Linux Linux, Linux Linux.
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