Description (CNA)
In the Linux kernel, the following vulnerability has been resolved: mm/mglru: fix div-by-zero in vmpressure_calc_level() evict_folios() uses a second pass to reclaim folios that have gone through page writeback and become clean before it finishes the first pass, since folio_rotate_reclaimable() cannot handle those folios due to the isolation. The second pass tries to avoid potential double counting by deducting scan_control->nr_scanned. However, this can result in underflow of nr_scanned, under a condition where shrink_folio_list() does not increment nr_scanned, i.e., when folio_trylock() fails. The underflow can cause the divisor, i.e., scale=scanned+reclaimed in vmpressure_calc_level(), to become zero, resulting in the following crash: [exception RIP: vmpressure_work_fn+101] process_one_work at ffffffffa3313f2b Since scan_control->nr_scanned has no established semantics, the potential double counting has minimal risks. Therefore, fix the problem by not deducting scan_control->nr_scanned in evict_folios().
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected 359a5e1416caaf9ce28396a65ed3e386cc5de663 before 8de7bf77f21068a5f602bb1e59adbc5ab533509d; affected 359a5e1416caaf9ce28396a65ed3e386cc5de663 before d6510f234c7d117790397f9bb150816b0a954a04; affected 359a5e1416caaf9ce28396a65ed3e386cc5de663 before a39e38be632f0e1c908d70d1c9cd071c03faf895; affected 359a5e1416caaf9ce28396a65ed3e386cc5de663 before 8b671fe1a879923ecfb72dda6caf01460dd885ef |
| Linux / Linux | affected 6.1; unaffected 0 before 6.1; unaffected 6.1.103 through 6.1.*; unaffected 6.6.44 through 6.6.*; unaffected 6.10.3 through 6.10.*; unaffected 6.11 through * |
CWE
No CWE identifiers supplied.
References
- https://git.kernel.org/stable/c/8de7bf77f21068a5f602bb1e59adbc5ab533509d
- https://git.kernel.org/stable/c/d6510f234c7d117790397f9bb150816b0a954a04
- https://git.kernel.org/stable/c/a39e38be632f0e1c908d70d1c9cd071c03faf895
- https://git.kernel.org/stable/c/8b671fe1a879923ecfb72dda6caf01460dd885ef
ADP enrichment
No English description supplied.
No references supplied.
No English description supplied.