In the Linux kernel, the following vulnerability has been resolved: smb: client: fix busy dentry warning on unmount after DIO Commit c68337442f03 ("cifs: Fix busy dentry used after unmounting") fixed the issue in cifs where deferred close of a file led to a dentry reference count not being released in umount, by flushing deferredclose_wq in cifs_kill_sb() to solve it. However, the cifs DIO path suffers from the same busy-dentry problem caused by a delayed dentry reference-count release: [dio] [cifsd] [close + umount] netfs_unbuffered_write_iter_locked ... cifs_demultiplex_thread netfs_unbuffered_write cifs_issue_write netfs_wait_for_in_progress_stream [1] ... netfs_write_subrequest_terminated netfs_subreq_clear_in_progress netfs_wake_collector // wake [1] netfs_put_subrequest netfs_put_request queue_work(system_dfl_wq, xxx) [2] // dio write return cifs_close _cifsFileInfo_put // cfile->count 2->1 --cfile->count [3] // umount cifs_kill_sb kill_anon_super // warning triggered! shrink_dcache_for_umount [4] [system_dfl_wq] [5] netfs_free_request ... _cifsFileInfo_put // cfile->count 1->0 --cfile->count queue_work(fileinfo_put_wq, xxx) [fileinfo_put_wq] [6] cifsFileInfo_put_work cifsFileInfo_put_final dput If the umount path is triggered before [5], it results warning: BUG: Dentry 00000000eab1f070{i=9a917b66ae404fec,n=test} still in use (1) [unmount of cifs cifs] The existing per-inode ictx->io_count wait in cifs_evict_inode() does not help: it lives in the inode eviction path, which runs after shrink_dcache_for_umount() has already warned about the busy dentries. Fix it by adding a per-superblock outstanding-rreq counter that is incremented in cifs_init_request() and decremented in cifs_free_request(). In cifs_kill_sb(), before kill_anon_super(), wait for this counter to reach 0 - which guarantees that all cleanup_work for this sb have run and thus all relevant cfile puts are queued on fileinfo_put_wq or serverclose_wq. Then drain the workqueue so the dentry refs are dropped. This is a targeted wait, not a flush of the system-wide system_dfl_wq.

There are packages installed that are affected by a vulnerability referenced in the following CVE:

  - In the Linux kernel, the following vulnerability has been resolved: smb: client: fix busy dentry warning
    on unmount after DIO Commit c68337442f03 ("cifs: Fix busy dentry used after unmounting") fixed the issue
    in cifs where deferred close of a file led to a dentry reference count not being released in umount, by
    flushing deferredclose_wq in cifs_kill_sb() to solve it. However, the cifs DIO path suffers from the same
    busy-dentry problem caused by a delayed dentry reference-count release: [dio] [cifsd] [close + umount]
    netfs_unbuffered_write_iter_locked ... cifs_demultiplex_thread netfs_unbuffered_write cifs_issue_write
    netfs_wait_for_in_progress_stream [1] ... netfs_write_subrequest_terminated netfs_subreq_clear_in_progress
    netfs_wake_collector // wake [1] netfs_put_subrequest netfs_put_request queue_work(system_dfl_wq, xxx) [2]
    // dio write return cifs_close _cifsFileInfo_put // cfile->count 2->1 --cfile->count [3] // umount
    cifs_kill_sb kill_anon_super // warning triggered! shrink_dcache_for_umount [4] [system_dfl_wq] [5]
    netfs_free_request ... _cifsFileInfo_put // cfile->count 1->0 --cfile->count queue_work(fileinfo_put_wq,
    xxx) [fileinfo_put_wq] [6] cifsFileInfo_put_work cifsFileInfo_put_final dput If the umount path is
    triggered before [5], it results warning: BUG: Dentry 00000000eab1f070{i=9a917b66ae404fec,n=test} still in
    use (1) [unmount of cifs cifs] The existing per-inode ictx->io_count wait in cifs_evict_inode() does not
    help: it lives in the inode eviction path, which runs after shrink_dcache_for_umount() has already warned
    about the busy dentries. Fix it by adding a per-superblock outstanding-rreq counter that is incremented in
    cifs_init_request() and decremented in cifs_free_request(). In cifs_kill_sb(), before kill_anon_super(),
    wait for this counter to reach 0 - which guarantees that all cleanup_work for this sb have run and thus
    all relevant cfile puts are queued on fileinfo_put_wq or serverclose_wq. Then drain the workqueue so the
    dentry refs are dropped. This is a targeted wait, not a flush of the system-wide system_dfl_wq.
    (CVE-2026-72315)

The remote Debian 13 host has packages installed that are affected by multiple vulnerabilities as referenced in the dsa-6568 advisory.

    - -------------------------------------------------------------------------     Debian Security Advisory DSA-6568-1                   security@debian.org     https://www.debian.org/security/                     Salvatore Bonaccorso     October 16, 2026                      https://www.debian.org/security/faq
    - -------------------------------------------------------------------------

    Package        : linux     CVE ID         : CVE-2025-38204 CVE-2025-40158 CVE-2026-52988 CVE-2026-72315                      CVE-2026-72463 CVE-2026-74347 CVE-2026-80935 CVE-2026-80937                      CVE-2026-80939 CVE-2026-80980 CVE-2026-81016 CVE-2026-89437                      CVE-2026-89441 CVE-2026-89445 CVE-2026-89452 CVE-2026-89467                      CVE-2026-89500 CVE-2026-89503 CVE-2026-89520 CVE-2026-89527                      CVE-2026-89633 CVE-2026-89638 CVE-2026-89766 CVE-2026-89795                      CVE-2026-89797 CVE-2026-89806 CVE-2026-89827 CVE-2026-89832                      CVE-2026-89837 CVE-2026-89838 CVE-2026-89840 CVE-2026-89859                      CVE-2026-89868 CVE-2026-89912 CVE-2026-89921 CVE-2026-89956                      CVE-2026-89971 CVE-2026-89972 CVE-2026-89996 CVE-2026-90002                      CVE-2026-90013 CVE-2026-90016 CVE-2026-90023 CVE-2026-90029                      CVE-2026-90030 CVE-2026-90146 CVE-2026-93179 CVE-2026-93196                      CVE-2026-93199 CVE-2026-93200 CVE-2026-93231 CVE-2026-93243                      CVE-2026-93244 CVE-2026-93285 CVE-2026-97527 CVE-2026-97528                      CVE-2026-97529 CVE-2026-97530 CVE-2026-97531 CVE-2026-97532                      CVE-2026-97534 CVE-2026-97535 CVE-2026-97536 CVE-2026-97537                      CVE-2026-97549 CVE-2026-97558 CVE-2026-97559 CVE-2026-97566                      CVE-2026-97567 CVE-2026-97571 CVE-2026-97574 CVE-2026-97594                      CVE-2026-97597 CVE-2026-97603 CVE-2026-97609 CVE-2026-97615                      CVE-2026-97618 CVE-2026-97619 CVE-2026-97620 CVE-2026-97901                      CVE-2026-97906 CVE-2026-97918 CVE-2026-97919 CVE-2026-97933                      CVE-2026-97934 CVE-2026-97935 CVE-2026-97938 CVE-2026-97939                      CVE-2026-97949 CVE-2026-97950 CVE-2026-98101 CVE-2026-98161                      CVE-2026-98167 CVE-2026-98168 CVE-2026-98169 CVE-2026-98170                      CVE-2026-98171 CVE-2026-98172 CVE-2026-98173 CVE-2026-98174                      CVE-2026-98175 CVE-2026-98179 CVE-2026-98181 CVE-2026-98182                      CVE-2026-98184 CVE-2026-98185 CVE-2026-98186 CVE-2026-98187                      CVE-2026-98188 CVE-2026-98189 CVE-2026-98190 CVE-2026-98191                      CVE-2026-98192 CVE-2026-98193 CVE-2026-98194 CVE-2026-98195                      CVE-2026-98196 CVE-2026-98197 CVE-2026-98198 CVE-2026-98199                      CVE-2026-98200 CVE-2026-98201 CVE-2026-98202 CVE-2026-98203                      CVE-2026-98204 CVE-2026-98205 CVE-2026-98206 CVE-2026-98207                      CVE-2026-98208 CVE-2026-98209 CVE-2026-98210 CVE-2026-98211                      CVE-2026-98212 CVE-2026-98213 CVE-2026-98214 CVE-2026-98215                      CVE-2026-98216 CVE-2026-98217 CVE-2026-98218 CVE-2026-98221                      CVE-2026-98222 CVE-2026-98227 CVE-2026-98229 CVE-2026-98230                      CVE-2026-98231 CVE-2026-98232 CVE-2026-98233 CVE-2026-98234                      CVE-2026-98235 CVE-2026-98236 CVE-2026-98237 CVE-2026-98238                      CVE-2026-98239 CVE-2026-98241 CVE-2026-98245 CVE-2026-98246                      CVE-2026-98247 CVE-2026-98248 CVE-2026-98249 CVE-2026-98251                      CVE-2026-98252 CVE-2026-98253 CVE-2026-98254 CVE-2026-98255                      CVE-2026-98257 CVE-2026-98260 CVE-2026-98261 CVE-2026-98262                      CVE-2026-98263 CVE-2026-98264 CVE-2026-98265 CVE-2026-98266                      CVE-2026-98267 CVE-2026-98269 CVE-2026-98270 CVE-2026-98271                      CVE-2026-98272 CVE-2026-98275 CVE-2026-98276 CVE-2026-98282                      CVE-2026-98283 CVE-2026-98287 CVE-2026-98290 CVE-2026-98291                      CVE-2026-98293 CVE-2026-98295 CVE-2026-98297 CVE-2026-98298                      CVE-2026-98299 CVE-2026-98300 CVE-2026-98301 CVE-2026-98302                      CVE-2026-98303 CVE-2026-98306 CVE-2026-98307 CVE-2026-98308                      CVE-2026-98309 CVE-2026-98311 CVE-2026-98312 CVE-2026-98314                      CVE-2026-98316 CVE-2026-98319 CVE-2026-98320 CVE-2026-98322                      CVE-2026-98323 CVE-2026-98325 CVE-2026-98326 CVE-2026-98327                      CVE-2026-98328 CVE-2026-98329 CVE-2026-98331 CVE-2026-98334                      CVE-2026-98335 CVE-2026-98336 CVE-2026-98337 CVE-2026-98339                      CVE-2026-98340 CVE-2026-98342 CVE-2026-98343 CVE-2026-98344                      CVE-2026-98345 CVE-2026-98346 CVE-2026-98347 CVE-2026-98348                      CVE-2026-98349 CVE-2026-98351 CVE-2026-98352 CVE-2026-98354                      CVE-2026-98357 CVE-2026-98358 CVE-2026-98359 CVE-2026-98360                      CVE-2026-98362 CVE-2026-98363 CVE-2026-98365 CVE-2026-98366                      CVE-2026-98367 CVE-2026-98368 CVE-2026-98369 CVE-2026-98370                      CVE-2026-98373 CVE-2026-98374 CVE-2026-98375 CVE-2026-98377                      CVE-2026-98378 CVE-2026-98379 CVE-2026-98380 CVE-2026-98381                      CVE-2026-98382 CVE-2026-98383 CVE-2026-98384 CVE-2026-98386                      CVE-2026-98403 CVE-2026-98406 CVE-2026-98407 CVE-2026-98409                      CVE-2026-98410 CVE-2026-98411 CVE-2026-98412 CVE-2026-98413                      CVE-2026-98416 CVE-2026-98417 CVE-2026-98419 CVE-2026-98421                      CVE-2026-98422 CVE-2026-98423 CVE-2026-98425 CVE-2026-98426                      CVE-2026-98428 CVE-2026-98429 CVE-2026-98430 CVE-2026-98432                      CVE-2026-99999     Debian Bug     : 1149499 1149564 1150891

    Several vulnerabilities have been discovered in the Linux kernel that     may lead to a privilege escalation, denial of service or information     leaks.

    For the stable distribution (trixie), these problems have been fixed in     version 6.12.113-1.

    We recommend that you upgrade your linux packages.

    For the detailed security status of linux please refer to its security     tracker page at:
    https://security-tracker.debian.org/tracker/linux

    Further information about Debian Security Advisories, how to apply     these updates to your system and frequently asked questions can be     found at: https://www.debian.org/security/

    Mailing list: debian-security-announce@lists.debian.org

Tenable has extracted the preceding description block directly from the Debian security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - smb: client: fix busy dentry warning on unmount after DIO Commit c68337442f03 (cifs: Fix busy dentry used     after unmounting) fixed the issue in cifs where deferred close of a file led to a dentry reference count     not being released in umount, by flushing deferredclose_wq in cifs_kill_sb() to solve it. However, the     cifs DIO path suffers from the same busy-dentry problem caused by a delayed dentry reference-count     release: [dio] [cifsd] [close + umount] netfs_unbuffered_write_iter_locked ... cifs_demultiplex_thread     netfs_unbuffered_write cifs_issue_write netfs_wait_for_in_progress_stream [1] ...
    netfs_write_subrequest_terminated netfs_subreq_clear_in_progress netfs_wake_collector // wake [1]     netfs_put_subrequest netfs_put_request queue_work(system_dfl_wq, xxx) [2] // dio write return cifs_close
    _cifsFileInfo_put // cfile->count 2->1 --cfile->count [3] // umount cifs_kill_sb kill_anon_super //     warning triggered! shrink_dcache_for_umount [4] [system_dfl_wq] [5] netfs_free_request ...
    _cifsFileInfo_put // cfile->count 1->0 --cfile->count queue_work(fileinfo_put_wq, xxx) [fileinfo_put_wq]     [6] cifsFileInfo_put_work cifsFileInfo_put_final dput If the umount path is triggered before [5], it     results warning: BUG: Dentry 00000000eab1f070{i=9a917b66ae404fec,n=test} still in use (1) [unmount of cifs     cifs] The existing per-inode ictx->io_count wait in cifs_evict_inode() does not help: it lives in the     inode eviction path, which runs after shrink_dcache_for_umount() has already warned about the busy     dentries. Fix it by adding a per-superblock outstanding-rreq counter that is incremented in     cifs_init_request() and decremented in cifs_free_request(). In cifs_kill_sb(), before kill_anon_super(),     wait for this counter to reach 0 - which guarantees that all cleanup_work for this sb have run and thus     all relevant cfile puts are queued on fileinfo_put_wq or serverclose_wq. Then drain the workqueue so the     dentry refs are dropped. This is a targeted wait, not a flush of the system-wide system_dfl_wq.
    (CVE-2026-72315)

Note that Nessus relies on the presence of the package as reported by the vendor.

ID	Name	Product	Family	Type	Severity
475025	Google: sys-kernel/cchost-kernel-6_12, sys-kernel/csql-kernel-6_12, sys-kernel/lakitu-kernel-6_12, sys-kernel/lakitu-nc-kernel-6_12: security update to 19216.739.5	Tenable Cloud Security	Google COS Security Checks	Local	high
475025	Google: sys-kernel/cchost-kernel-6_12, sys-kernel/csql-kernel-6_12, sys-kernel/lakitu-kernel-6_12, sys-kernel/lakitu-nc-kernel-6_12: security update to 19216.739.5	Tenable Self-Hosted Container Security	Google COS Security Checks	Local	high
366507	Debian dsa-6568 : ata-modules-6.12.111+deb13-armmp-di - security update	Nessus	Debian Local Security Checks	Local	medium
365768	Ubuntu 26.04 LTS : Linux kernel (Azure) vulnerabilities (USN-8888-1)	Nessus	Ubuntu Local Security Checks	Local	medium
365767	Ubuntu 26.04 LTS : Linux kernel vulnerabilities (USN-8887-1)	Nessus	Ubuntu Local Security Checks	Local	medium
365463	Ubuntu 26.04 LTS : Linux kernel (OEM) vulnerabilities (USN-8889-1)	Nessus	Ubuntu Local Security Checks	Local	medium
335614	Linux Distros Unpatched Vulnerability : CVE-2026-72315	Nessus	Misc.	Local	high

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