In the Linux kernel, the following vulnerability has been resolved: s390/uv: Don't call folio_wait_writeback() without a folio reference folio_wait_writeback() requires that no spinlocks are held and that a folio reference is held, as documented. After we dropped the PTL, the folio could get freed concurrently. So grab a temporary reference.
https://git.kernel.org/stable/c/b21aba72aadd94bdac275deab021fc84d6c72b16
https://git.kernel.org/stable/c/8736604ef53359a718c246087cd21dcec232d2fb
https://git.kernel.org/stable/c/3f29f6537f54d74e64bac0a390fb2e26da25800d
https://git.kernel.org/stable/c/1a1eb2f3fc453dcd52726d13e863938561489cb7