{"id":5452,"date":"2026-09-04T18:47:50","date_gmt":"2026-09-04T10:47:50","guid":{"rendered":"https:\/\/www.54iter.cn\/?vuln=cve-2026-68388"},"modified":"2026-09-04T18:47:50","modified_gmt":"2026-09-04T10:47:50","slug":"cve-2026-68388","status":"publish","type":"vuln","link":"https:\/\/www.54iter.cn\/?vuln=cve-2026-68388","title":{"rendered":"CVE-2026-68388 [CRITICAL] &#8211; In the Linux kernel, the following vulnerability has been resolved:\n\nsmb\/client: handle ov"},"content":{"rendered":"<p>In the Linux kernel, the following vulnerability has been resolved:<\/p>\n<p>smb\/client: handle overlapping allocated ranges in fallocate<\/p>\n<p>smb3_simple_fallocate_range() can skip holes when an allocated range<br \/>\nreturned by the server starts before the current fallocate offset. The<br \/>\nskipped hole is not zero-filled, but fallocate still returns success. A<br \/>\nlater write to that hole may therefore fail with ENOSPC.<\/p>\n<p>The function queries allocated ranges so that it can preserve existing<br \/>\ncontents and write zeroes only into holes. However, the server may return<br \/>\na range that starts before the current fallocate offset.<\/p>\n<p>For example, assume the fallocate request is [100, 400) and the only<br \/>\nallocated range returned by the server is [0, 200):<\/p>\n<p>        Request:      [100, 400)<br \/>\n        Server range: [  0, 200)  allocated<\/p>\n<p>        Correct:<br \/>\n        [100, 200)    allocated data, skip<br \/>\n        [200, 400)    hole, zero-fill<\/p>\n<p>        Current:<br \/>\n        [100, 300)    skipped<br \/>\n        [300, 400)    zero-filled afterwards<\/p>\n<p>The current code adds the full server range length, 200, to the current<br \/>\noffset 100 and moves to 300. As a result, the hole in [200, 300) is<br \/>\nskipped without being zero-filled.<\/p>\n<p>Fix this by advancing only over the part of the allocated range that<br \/>\noverlaps the current fallocate offset.  Ignore ranges that end before the<br \/>\ncurrent offset and reject ranges whose end offset overflows.<\/p>\n<p>This also prevents a malformed range length from causing an out-of-bounds<br \/>\nzero-buffer read.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>In the Linux kernel, the following vulnerability has been resolved:<\/p>\n<p>smb\/client: handle overlapping allocated ranges in fallocate<\/p>\n<p>smb3_simple_fallocate_range() can skip holes when an allocated range<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-5452","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/5452","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln"}],"about":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/types\/vuln"}],"wp:attachment":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=5452"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=5452"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=5452"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}