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VulnerabilityPublished Updated

CVE-2026-72080: Linux kernel · fs/resctrl: Fix use-after-free during unmount

Affects Linux kernelSource CVE Database V5

0

Not known to be exploited · CVSS 7.8 High · fixed in 52fce648607e0d6a76eeb443d78708c49df1c554 : patch Linux kernel soon.

Data as of 26 Oct 2026, 13:47 UTC

CVSS 3.1 base score
7.8High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.1% chance of exploitation in 30 days – higher than 6% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CISA SSVC
Exploitation
No evidence of active exploitation and no public proof of concept
Automatable
Attackers cannot reliably automate steps 1–4 of the kill chain
Technical impact
Total control over the software or total information disclosure

CISA SSVC assessment, 2026-10-16.

Patch
Available – fixed in 52fce648607e0d6a76eeb443d78708c49df1c554, 7d330a1d663381579b9d5dafa642b1b3158a0ce2, 7b7bb07efe41bb646a93c4624aa2bb35df190342
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 15 Aug 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Upgrade Linux kernel to 52fce648607e0d6a76eeb443d78708c49df1c554, 7d330a1d663381579b9d5dafa642b1b3158a0ce2 or 7b7bb07efe41bb646a93c4624aa2bb35df190342.

Affected software

ProductAffectedFixed in
LinuxLinuxAffected
  • ≥ 2a65660385444e9d9deffe995c71ee20443ef76e, < 52fce648607e0d6a76eeb443d78708c49df1c554
Fixed in
  • 52fce648607e0d6a76eeb443d78708c49df1c554
LinuxLinuxAffected
  • ≥ 2a65660385444e9d9deffe995c71ee20443ef76e, < 7d330a1d663381579b9d5dafa642b1b3158a0ce2
Fixed in
  • 7d330a1d663381579b9d5dafa642b1b3158a0ce2
LinuxLinuxAffected
  • ≥ 2a65660385444e9d9deffe995c71ee20443ef76e, < 7b7bb07efe41bb646a93c4624aa2bb35df190342
Fixed in
  • 7b7bb07efe41bb646a93c4624aa2bb35df190342
LinuxLinuxAffected
  • =6.16
Fixed in–

Description

In the Linux kernel, the following vulnerability has been resolved: fs/resctrl: Fix use-after-free during unmount During unmount or failure teardown all mon_data structures that contain monitoring event file private data are freed after which kernfs nodes are removed. However, the RDT_DELETED flag is never set for the statically allocated default resource group. A concurrent reader of an event file associated with the default resource group may, after dropping kernfs active protection, block on rdtgroup_mutex while unmount proceeds to free the file private data and destroy the kernfs node without waiting for the reader. When the mutex is released, the reader wakes up, observes that RDT_DELETED is not set for the default group, and dereferences the already-freed file private data. The scenario can be depicted as follows: CPU0 CPU1 /* * Default resource group's * monitoring data accessible via * kernfs file with kernfs_node::priv * pointing to a struct mon_data. * User opens the file for reading. */ rdtgroup_mondata_show() /* arch encounters fatal error */ rdtgroup_kn_lock_live() resctrl_exit() atomic_inc(&rdtgroup_default.waitcount) cpus_read_lock() kernfs_break_active_protection(kn) mutex_lock(&rdtgroup_mutex) cpus_read_lock() resctrl_fs_teardown() mutex_lock(&rdtgroup_mutex) rmdir_all_sub() mon_put_kn_priv() /* Delete all mon_data structures */ rdtgroup_destroy_root() kernfs_destroy_root() rdtgroup_default.kn = NULL mutex_unlock(&rdtgroup_mutex) /* * rdtgroup_default.flags is empty so * rdtgroup_kn_lock_live() returns * &rdtgroup_default */ md = of->kn->priv; /* md points to freed mon_data */ Set RDT_DELETED for the default group unconditionally since the flag does not lead to the freeing of this statically allocated group. Do not allow a new resctrl mount if there are any waiters on default group of previous mount. A new mount will re-initialize the default group that would appear to waiters from previous mount as though the default group is accessible causing them to access the mon_data structures from the previous mount that have been removed.

References

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