CVE-2026-64159

*** Pendiente de traducción *** In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> netfs: Fix zeropoint update where i_size &gt; remote_i_size<br /> <br /> Fix the update of the zero point[*] by netfs_release_folio() when there is<br /> uncommitted data in the pagecache beyond the folio being released but the<br /> on-server EOF is in this folio (ie. i_size &gt; remote_i_size). The update<br /> needs to limit zero_point to remote_i_size, not i_size as i_size is a local<br /> phenomenon reflecting updates made locally to the pagecache, not stuff<br /> written to the server. remote_i_size tracks the server&amp;#39;s i_size.<br /> <br /> [*] The zero point is the file position from which we can assume that the<br /> server will just return zeros, so we can avoid generating reads.<br /> <br /> Note that netfs_invalidate_folio() probably doesn&amp;#39;t need fixing as<br /> zero_point should be updated by setattr after truncation or fallocate.<br /> <br /> Found with:<br /> <br /> fsx -q -N 1000000 -p 10000 -o 128000 -l 600000 \<br /> /xfstest.test/junk --replay-ops=junk.fsxops<br /> <br /> using the following as junk.fsxops:<br /> <br /> truncate 0x0 0x1bbae 0x82864<br /> write 0x3ef2e 0xf9c8 0x1bbae<br /> write 0x67e05 0xcb5a 0x4e8f6<br /> mapread 0x57781 0x85b6 0x7495f<br /> copy_range 0x5d3d 0x10329 0x54fac 0x7495f<br /> write 0x64710 0x1c2b 0x7495f<br /> mapread 0x64000 0x1000 0x7495f<br /> <br /> on cifs with the default cache option.<br /> <br /> It shows read-gaps on folio 0x64 failing with a short read (ie. it hits<br /> EOF) if the FMODE_READ check is commented out in netfs_perform_write():<br /> <br /> if (//(file-&gt;f_mode &amp; FMODE_READ) ||<br /> netfs_is_cache_enabled(ctx)) {<br /> <br /> and no fscache. This was initially found with the generic/522 xfstest.