https://vulnerability.circl.lu Contains only the most 10 recent entries. http://www.rssboard.org/rss-specification python-feedgen en Tue, 29 Sep 2026 06:35:16 +0000 https://vulnerability.circl.lu/vuln/cve-2026-89712 <p><strong>Affected:</strong> Linux</p> <p>In the Linux kernel, the following vulnerability has been resolved:</p> <p>NFSD: restart ssc_expire_umount walk after dropping nfsd_ssc_lock</p> <p>nfsd4_ssc_expire_umount() walks nn-&gt;nfsd_ssc_mount_list with list_for_each_entry_safe(ni, tmp, ...). For each expired entry it sets nsui_busy = true, drops nfsd_ssc_lock to run mntput() on the source vfsmount, then reacquires the lock to list_del + kfree the entry and continue iterating via the macro&#39;s saved tmp pointer.</p> <p>The nsui_busy flag protects the current ni from concurrent nfsd4_ssc_setup_dul() finders during the lock-drop window, but it does not pin tmp. Another nfsd RPC thread that fails its source- server mount and reaches nfsd4_ssc_cancel_dul() will, during that same window, take nfsd_ssc_lock, list_del + kfree its own ssc_umount item, and release the lock. If that item is the saved tmp of the expire walk, the next iteration dereferences a freed nfsd4_ssc_umount_item.</p> <p>Restart the walk from the head after the mntput() unlock window so no saved next pointer survives the lock-drop. The list is bounded by the number of active inter-server source mounts (typically small) and the expire delayed-work runs periodically rather than per-IO, so the restart is cheap.</p> <p><strong>Affected:</strong> Linux</p> <p>In the Linux kernel, the following vulnerability has been resolved:</p> <p>NFSD: restart ssc_expire_umount walk after dropping nfsd_ssc_lock</p> <p>nfsd4_ssc_expire_umount() walks nn-&gt;nfsd_ssc_mount_list with list_for_each_entry_safe(ni, tmp, ...). For each expired entry it sets nsui_busy = true, drops nfsd_ssc_lock to run mntput() on the source vfsmount, then reacquires the lock to list_del + kfree the entry and continue iterating via the macro&#39;s saved tmp pointer.</p> <p>The nsui_busy flag protects the current ni from concurrent nfsd4_ssc_setup_dul() finders during the lock-drop window, but it does not pin tmp. Another nfsd RPC thread that fails its source- server mount and reaches nfsd4_ssc_cancel_dul() will, during that same window, take nfsd_ssc_lock, list_del + kfree its own ssc_umount item, and release the lock. If that item is the saved tmp of the expire walk, the next iteration dereferences a freed nfsd4_ssc_umount_item.</p> <p>Restart the walk from the head after the mntput() unlock window so no saved next pointer survives the lock-drop. The list is bounded by the number of active inter-server source mounts (typically small) and the expire delayed-work runs periodically rather than per-IO, so the restart is cheap.</p> https://vulnerability.circl.lu/vuln/cve-2026-89712