CVE-2021-47365

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> afs: Fix page leak<br /> <br /> There&amp;#39;s a loop in afs_extend_writeback() that adds extra pages to a write<br /> we want to make to improve the efficiency of the writeback by making it<br /> larger. This loop stops, however, if we hit a page we can&amp;#39;t write back<br /> from immediately, but it doesn&amp;#39;t get rid of the page ref we speculatively<br /> acquired.<br /> <br /> This was caused by the removal of the cleanup loop when the code switched<br /> from using find_get_pages_contig() to xarray scanning as the latter only<br /> gets a single page at a time, not a batch.<br /> <br /> Fix this by putting the page on a ref on an early break from the loop.<br /> Unfortunately, we can&amp;#39;t just add that page to the pagevec we&amp;#39;re employing<br /> as we&amp;#39;ll go through that and add those pages to the RPC call.<br /> <br /> This was found by the generic/074 test. It leaks ~4GiB of RAM each time it<br /> is run - which can be observed with "top".