CVE-2026-64108

*** Pendiente de traducción *** In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> cifs: Fix busy dentry used after unmounting<br /> <br /> Since commit 340cea84f691c ("cifs: open files should not hold ref on<br /> superblock"), cifs file only holds the dentry ref_cnt, the cifs file<br /> close work(cfile-&gt;deferred) could be executed after unmounting, which<br /> will trigger a warning in generic_shutdown_super:<br /> BUG: Dentry 00000000a14a6845{i=c,n=file} still in use (1) [unmount of<br /> cifs cifs]<br /> <br /> The detailed processs is:<br /> process A process B kworker<br /> fd = open(PATH)<br /> vfs_open<br /> file-&gt;__f_path = *path // dentry-&gt;d_lockref.count = 1<br /> cifs_open<br /> cifs_new_fileinfo<br /> cfile-&gt;dentry = dget(dentry) // dentry-&gt;d_lockref.count = 2<br /> close(fd)<br /> __fput<br /> cifs_close<br /> queue_delayed_work(deferredclose_wq, cfile-&gt;deferred)<br /> dput(dentry) // dentry-&gt;d_lockref.count = 1<br /> smb2_deferred_work_close<br /> _cifsFileInfo_put<br /> list_del(&amp;cifs_file-&gt;flist)<br /> umount<br /> cleanup_mnt<br /> deactivate_super<br /> cifs_kill_sb<br /> cifs_close_all_deferred_files_sb<br /> cifs_close_all_deferred_files<br /> // cannot find cfile, skip _cifsFileInfo_put<br /> kill_anon_super<br /> generic_shutdown_super<br /> shrink_dcache_for_umount<br /> umount_check<br /> WARN ! // dentry-&gt;d_lockref.count = 1<br /> cifsFileInfo_put_final<br /> dput(cifs_file-&gt;dentry)<br /> // dentry-&gt;d_lockref.count = 0<br /> <br /> Fix it by flushing &amp;#39;deferredclose_wq&amp;#39; before calling kill_anon_super.<br /> <br /> Fetch a reproducer in https://bugzilla.kernel.org/show_bug.cgi?id=221548.