CVE-2024-46838

userfaultfd: don't BUG_ON() if khugepaged yanks our page table

Description

In the Linux kernel, the following vulnerability has been resolved: userfaultfd: don't BUG_ON() if khugepaged yanks our page table Since khugepaged was changed to allow retracting page tables in file mappings without holding the mmap lock, these BUG_ON()s are wrong - get rid of them. We could also remove the preceding "if (unlikely(...))" block, but then we could reach pte_offset_map_lock() with transhuge pages not just for file mappings but also for anonymous mappings - which would probably be fine but I think is not necessarily expected.

5.5

CVSS

Severity: Medium

CVSS 3.1 •

EPSS 0.03%

Affected: Linux Linux

References

Link	Tags
https://git.kernel.org/stable/c/4a594acc12d5954cdc71d4450a386748bf3d136a	patch
https://git.kernel.org/stable/c/db978287e908d48b209e374b00d847b2d785e0a9	patch
https://git.kernel.org/stable/c/4828d207dc5161dc7ddf9a4f6dcfd80c7dd7d20a	patch

Frequently Asked Questions

What is the severity of CVE-2024-46838?: CVE-2024-46838 has been scored as a medium severity vulnerability.
How to fix CVE-2024-46838?: To fix CVE-2024-46838, 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-2024-46838 being actively exploited in the wild?: As for now, there are no information to confirm that CVE-2024-46838 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-2024-46838?: CVE-2024-46838 affects Linux Linux, Linux Linux.

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