UBUNTU-CVE-2025-40218
In the Linux kernel, the following vulnerability has been resolved: mm/damon/vaddr: do not repeat pte_offset_map_lock() until success DAMON's virtual address space operation set implementation (vaddr) calls pte_offset_map_lock() inside the page table walk callback function. This is for reading and writing page table accessed bits. If pte_offset_map_lock() fails, it retries by returning the page table walk callback function with ACTION_AGAIN. pte_offset_map_lock() can continuously fail if the target is a pmd migration entry, though. Hence it could cause an infinite page table walk if the migration cannot be done until the page table walk is finished. This indeed caused a soft lockup when CPU hotplugging and DAMON were running in parallel. Avoid the infinite loop by simply not retrying the page table walk. DAMON is promising only a best-effort accuracy, so missing access to such pages is no problem.
02 / AFFECTED SOFTWARE
Affected packages
11 explicit affected versions
50 explicit affected versions
6 explicit affected versions
12 explicit affected versions
19 explicit affected versions
10 explicit affected versions
6 explicit affected versions
24 explicit affected versions
10 explicit affected versions
30 explicit affected versions
26 explicit affected versions
7 explicit affected versions
34 explicit affected versions
13 explicit affected versions
37 explicit affected versions
35 explicit affected versions
18 explicit affected versions
39 explicit affected versions
13 explicit affected versions
4 explicit affected versions
23 explicit affected versions
45 explicit affected versions
1 explicit affected versions
21 explicit affected versions
9 explicit affected versions
16 explicit affected versions
10 explicit affected versions
12 explicit affected versions
41 explicit affected versions
8 explicit affected versions
7 explicit affected versions
12 explicit affected versions
11 explicit affected versions
7 explicit affected versions
12 explicit affected versions
14 explicit affected versions
10 explicit affected versions
1 explicit affected versions
7 explicit affected versions
9 explicit affected versions
12 explicit affected versions
1 explicit affected versions
12 explicit affected versions
34 explicit affected versions
16 explicit affected versions
9 explicit affected versions
23 explicit affected versions
27 explicit affected versions
10 explicit affected versions
37 explicit affected versions
10 explicit affected versions
1 explicit affected versions
13 explicit affected versions
33 explicit affected versions
3 explicit affected versions
10 explicit affected versions
11 explicit affected versions
26 explicit affected versions
5 explicit affected versions
13 explicit affected versions
29 explicit affected versions
13 explicit affected versions
12 explicit affected versions
34 explicit affected versions
34 explicit affected versions
33 explicit affected versions
23 explicit affected versions
10 explicit affected versions
13 explicit affected versions
12 explicit affected versions
11 explicit affected versions
5 explicit affected versions
12 explicit affected versions
1 explicit affected versions
7 explicit affected versions
12 explicit affected versions
8 explicit affected versions
5 explicit affected versions
10 explicit affected versions
26 explicit affected versions
32 explicit affected versions
28 explicit affected versions
40 explicit affected versions
11 explicit affected versions
1 explicit affected versions
13 explicit affected versions
39 explicit affected versions
16 explicit affected versions
43 explicit affected versions
3 explicit affected versions
7 explicit affected versions
7 explicit affected versions
51 explicit affected versions
8 explicit affected versions
18 explicit affected versions
35 explicit affected versions
12 explicit affected versions
1 explicit affected versions
27 explicit affected versions
36 explicit affected versions
8 explicit affected versions
5 explicit affected versions
8 explicit affected versions
10 explicit affected versions
7 explicit affected versions
39 explicit affected versions
13 explicit affected versions
13 explicit affected versions
7 explicit affected versions
8 explicit affected versions
10 explicit affected versions
12 explicit affected versions
9 explicit affected versions
44 explicit affected versions
16 explicit affected versions
3 explicit affected versions
13 explicit affected versions
26 explicit affected versions
45 explicit affected versions
37 explicit affected versions
44 explicit affected versions
14 explicit affected versions
38 explicit affected versions
9 explicit affected versions
9 explicit affected versions
11 explicit affected versions
32 explicit affected versions
15 explicit affected versions
6 explicit affected versions
8 explicit affected versions
7 explicit affected versions
4 explicit affected versions
1 explicit affected versions
13 explicit affected versions
43 explicit affected versions
6 explicit affected versions
10 explicit affected versions
8 explicit affected versions
38 explicit affected versions
14 explicit affected versions
4 explicit affected versions
78 explicit affected versions
6 explicit affected versions
11 explicit affected versions
1 explicit affected versions
12 explicit affected versions
32 explicit affected versions
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
In the Linux kernel, the following vulnerability has been resolved: mm/damon/vaddr: do not repeat pte_offset_map_lock() until success DAMON's virtual address space operation set implementation (vaddr) calls pte_offset_map_lock() inside the page table walk callback function. This is for reading and writing page table accessed bits. If pte_offset_map_lock() fails, it retries by returning the page table walk callback function with ACTION_AGAIN. pte_offset_map_lock() can continuously fail if the target is a pmd migration entry, though. Hence it could cause an infinite page table walk if the migration cannot be done until the page table walk is finished. This indeed caused a soft lockup when CPU hotplugging and DAMON were running in parallel. Avoid the infinite loop by simply not retrying the page table walk. DAMON is promising only a best-effort accuracy, so missing access to such pages is no problem.
05 / REFERENCES
Further evidence
- https://git.kernel.org/linus/b93af2cc8e036754c0d9970d9ddc47f43cc94b9f
- https://git.kernel.org/stable/c/0ccd91cf749536d41307a07e60ec14ab0dbf21f5
- https://git.kernel.org/stable/c/677ebfe5d00f94adec0c0204f6e6e2a82d3f77bf
- https://git.kernel.org/stable/c/ac42320ec873bfe726141069cfdd90ee5bc4e885
- https://git.kernel.org/stable/c/b93af2cc8e036754c0d9970d9ddc47f43cc94b9f
- https://ubuntu.com/security/CVE-2025-40218
- https://ubuntu.com/security/notices/USN-8029-1
- https://ubuntu.com/security/notices/USN-8029-2
- https://ubuntu.com/security/notices/USN-8029-3
- https://ubuntu.com/security/notices/USN-8030-1
- https://ubuntu.com/security/notices/USN-8048-1
- https://ubuntu.com/security/notices/USN-8095-1
- https://ubuntu.com/security/notices/USN-8095-2
- https://ubuntu.com/security/notices/USN-8095-3
- https://ubuntu.com/security/notices/USN-8095-4
- https://ubuntu.com/security/notices/USN-8095-5
- https://ubuntu.com/security/notices/USN-8100-1
- https://ubuntu.com/security/notices/USN-8125-1
- https://ubuntu.com/security/notices/USN-8126-1
- https://ubuntu.com/security/notices/USN-8165-1
- https://ubuntu.com/security/notices/USN-8261-1
- https://www.cve.org/CVERecord?id=CVE-2025-40218