Description
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.
Product status
7780d04046a2288ab85d88bedacc60fa4fad9971 (git) before 677ebfe5d00f94adec0c0204f6e6e2a82d3f77bf
7780d04046a2288ab85d88bedacc60fa4fad9971 (git) before ac42320ec873bfe726141069cfdd90ee5bc4e885
7780d04046a2288ab85d88bedacc60fa4fad9971 (git) before 0ccd91cf749536d41307a07e60ec14ab0dbf21f5
7780d04046a2288ab85d88bedacc60fa4fad9971 (git) before b93af2cc8e036754c0d9970d9ddc47f43cc94b9f
6.5
Any version before 6.5
6.6.113 (semver)
6.12.54 (semver)
6.17.4 (semver)
6.18 (original_commit_for_fix)
References
git.kernel.org/...c/677ebfe5d00f94adec0c0204f6e6e2a82d3f77bf
git.kernel.org/...c/ac42320ec873bfe726141069cfdd90ee5bc4e885
git.kernel.org/...c/0ccd91cf749536d41307a07e60ec14ab0dbf21f5
git.kernel.org/...c/b93af2cc8e036754c0d9970d9ddc47f43cc94b9f
