CVE-2024-36943: fs/proc/task_mmu: fix loss of young/dirty bits during pagemap scan
In the Linux kernel, the following vulnerability has been resolved:
fs/proc/taskmmu: fix loss of young/dirty bits during pagemap scan
makeuffdwppte() was previously doing:
pte = ptepget(ptep); ptepmodifyprotstart(ptep); pte = ptemkuffdwp(pte); ptepmodifyprotcommit(ptep, pte);
But if another thread accessed or dirtied the pte between the first 2 calls, this could lead to loss of that information. Since ptepmodifyprotstart() gets and clears atomically, the following is the correct pattern and prevents any possible race. Any access after the first call would see an invalid pte and cause a fault:
pte = ptepmodifyprotstart(ptep); pte = ptemkuffdwp(pte); ptepmodifyprotcommit(ptep, pte);
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
debian/linuxto a version that resolves this vulnerability.Fixed in 5.10.223-1Fixed in 5.10.234-1Fixed in 6.1.129-1Fixed in 6.1.135-1Fixed in 6.12.22-1Fixed in 6.12.25-1
Event History
Frequently Asked Questions
What is the severity of CVE-2024-36943?
CVE-2024-36943 has a medium severity rating due to its potential impact on the Linux kernel's memory management.
How do I fix CVE-2024-36943?
To fix CVE-2024-36943, update your Linux kernel to one of the following versions: 5.10.223-1, 5.10.226-1, 6.1.123-1, 6.1.119-1, 6.12.11-1, or 6.12.12-1.
Which systems are affected by CVE-2024-36943?
CVE-2024-36943 affects systems running specific versions of the Linux kernel as identified in the vulnerability report.
Is CVE-2024-36943 being actively exploited?
As of now, there are no known active exploits for CVE-2024-36943, but it is advisable to apply the necessary patches promptly.
What components of the Linux kernel are impacted by CVE-2024-36943?
CVE-2024-36943 impacts the memory management subsystem of the Linux kernel, specifically in the fs/proc/task_mmu functions.