CVE-2026-64294

Updated on 25 Jul 2026

Severity

5.5 Medium severity

Details

CVSS score
5.5
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Overview

About vulnerability

In the Linux kernel, the following vulnerability has been resolved:

mm: do file ownership checks with the proper mount idmap

Ever since idmapped mounts were introduced, inode ownership checks (for side-channel protection) in mincore() and madvise(MADV_PAGEOUT) were done against the nop_mnt_idmap, which completely ignores the file’s mount’s idmap. This results in odd edgecases like:

  1. mount/bind-mount with an idmap userA:userB:1
  2. userB runs an owner_or_capable() check on file that is owned by userA on-disk/in-memory, but owned by userB after idmap translation
  3. owner_or_capable() mysteriously fails as the correct idmap wasn’t supplied

In the case of mincore/madvise MADV_PAGEOUT, this is usually benign, because file_permission(file, MAY_WRITE) will probably succeed, as it uses the proper idmap internally, but it does not need to be the case on e.g a 0444 file where even the owner itself doesn’t have permissions to write to it.

Since this is clearly not trivial to get right, introduce a file_owner_or_capable() that can carry the correct semantics, and switch the various users in mm to it.

The issue was found by manual code inspection & an off-list discussion with Jan Kara.

Details

Affected packages:
kernel @ 5.14.0 (+2 more)

Fixes

KernelCare state

Live-patch status from KernelCare for each operating system.

Operating system Status Covered kernels
AlmaLinux 9.6 ESU Planned —
Debian 12 Released
43 kernels
  • 6.1.177-1
  • 6.1.180-1
  • 6.1.38-1
  • 6.1.38-2
  • 6.1.38-4
  • 6.1.52-1
  • 6.1.55-1
  • 6.1.64-1
  • 6.1.66-1
  • 6.1.69-1
  • 6.1.76-1
  • 6.1.27-1
  • 6.1.67-1
  • 6.1.85-1
  • 6.1.90-1
  • 6.1.94-1
  • 6.1.99-1
  • 6.1.106-3
  • 6.1.112-1
  • 6.1.115-1
  • 6.1.119-1
  • 6.1.123-1
  • 6.1.128-1
  • 6.1.124-1
  • 6.1.129-1
  • 6.1.133-1
  • 6.1.135-1
  • 6.1.137-1
  • 6.1.140-1
  • 6.1.139-1
  • 6.1.147-1
  • 6.1.148-1
  • 6.1.153-1
  • 6.1.158-1
  • 6.1.159-1
  • 6.1.162-1
  • 6.1.164-1
  • 6.1.170-1
  • 6.1.170-3
  • 6.1.172-1
  • 6.1.174-1
  • 6.1.170-2
  • 6.1.176-1
Debian 13 Released
12 kernels
  • 6.12.85-1
  • 6.12.86-1
  • 6.12.88-1
  • 6.12.74-2
  • 6.12.73-1
  • 6.12.63-1
  • 6.12.69-1
  • 6.12.74-1
  • 6.12.90-1
  • 6.12.90-2
  • 6.12.94-1
  • 6.12.95-1
Oracle Linux 8 UEK 7 Released
112 kernels
  • 5.15.0-102.110.5.el8uek
  • 5.15.0-101.103.2.1.el8uek
  • 5.15.0-8.91.4.1.el8uek
  • 5.15.0-7.86.6.1.el8uek
  • 5.15.0-2.52.3.el8uek
  • 5.15.0-100.96.32.el8uek
  • 5.15.0-5.76.5.1.el8uek
  • 5.15.0-6.80.3.1.el8uek
  • 5.15.0-3.60.5.1.el8uek
  • 5.15.0-0.30.20.el8uek
  • 5.15.0-1.43.4.1.el8uek
  • 5.15.0-0.30.20.1.el8uek
  • 5.15.0-1.43.4.2.el8uek
  • 5.15.0-4.70.5.2.el8uek
  • 5.15.0-104.119.4.2.el8uek
  • 5.15.0-0.30.19.el8uek
  • 5.15.0-105.125.6.2.el8uek
  • 5.15.0-105.125.6.2.1.el8uek
  • 5.15.0-105.125.6.2.2.el8uek
  • 5.15.0-106.131.4.el8uek
  • 5.15.0-200.131.27.el8uek
  • 5.15.0-200.131.27.1.el8uek
  • 5.15.0-201.135.6.el8uek
  • 5.15.0-202.135.2.el8uek
  • 5.15.0-102.110.5.1.el8uek
  • 5.15.0-103.114.4.el8uek
  • 5.15.0-203.146.5.1.el8uek
  • 5.15.0-204.147.6.2.el8uek
  • 5.15.0-204.147.6.3.el8uek
  • 5.15.0-205.149.5.1.el8uek
  • 5.15.0-205.149.5.4.el8uek
  • 5.15.0-206.153.7.el8uek
  • 5.15.0-206.153.7.1.el8uek
  • 5.15.0-207.156.6.el8uek
  • 5.15.0-208.159.3.el8uek
  • 5.15.0-208.159.3.2.el8uek
  • 5.15.0-209.161.7.el8uek
  • 5.15.0-209.161.7.1.el8uek
  • 5.15.0-209.161.7.2.el8uek
  • 5.15.0-210.163.7.el8uek
  • 5.15.0-300.163.18.el8uek
  • 5.15.0-300.163.18.1.el8uek
  • 5.15.0-300.163.18.1.1.el8uek
  • 5.15.0-301.163.5.2.el8uek
  • 5.15.0-302.167.6.el8uek
  • 5.15.0-300.163.18.7.el8uek
  • 5.15.0-302.167.6.1.el8uek
  • 5.15.0-303.171.5.2.el8uek
  • 5.15.0-303.171.5.2.1.el8uek
  • 5.15.0-304.171.4.el8uek
  • 5.15.0-304.171.4.1.el8uek
  • 5.15.0-304.171.4.3.el8uek
  • 5.15.0-303.171.5.2.2.el8uek
  • 5.15.0-305.176.4.el8uek
  • 5.15.0-306.177.4.el8uek
  • 5.15.0-306.177.4.1.el8uek
  • 5.15.0-307.178.5.el8uek
  • 5.15.0-308.179.6.el8uek
  • 5.15.0-308.179.6.2.el8uek
  • 5.15.0-308.179.6.3.el8uek
  • 5.15.0-309.180.4.el8uek
  • 5.15.0-308.179.6.7.el8uek
  • 5.15.0-309.180.4.2.el8uek
  • 5.15.0-308.179.6.11.el8uek
  • 5.15.0-310.184.5.2.el8uek
  • 5.15.0-310.184.5.3.el8uek
  • 5.15.0-311.185.9.el8uek
  • 5.15.0-308.179.6.14.el8uek
  • 5.15.0-312.187.5.el8uek
  • 5.15.0-312.187.5.1.el8uek
  • 5.15.0-312.187.5.2.el8uek
  • 5.15.0-312.187.5.3.el8uek
  • 5.15.0-308.179.6.16.el8uek
  • 5.15.0-313.189.5.1.el8uek
  • 5.15.0-313.189.5.2.el8uek
  • 5.15.0-313.189.5.3.el8uek
  • 5.15.0-314.193.5.3.el8uek
  • 5.15.0-314.193.5.4.el8uek
  • 5.15.0-314.193.5.5.el8uek
  • 5.15.0-315.196.5.1.el8uek
  • 5.15.0-315.196.5.2.el8uek
  • 5.15.0-316.196.4.1.el8uek
  • 5.15.0-316.196.4.2.el8uek
  • 5.15.0-317.197.5.1.el8uek
  • 5.15.0-317.197.5.2.el8uek
  • 5.15.0-318.199.3.2.el8uek
  • 5.15.0-318.199.3.2.1.el8uek
  • 5.15.0-319.201.4.2.el8uek
  • 5.15.0-319.201.4.3.el8uek
  • 5.15.0-319.201.4.4.el8uek
  • 5.15.0-319.201.4.6.el8uek
  • 5.15.0-320.202.8.2.el8uek
  • 5.15.0-320.202.8.3.el8uek
  • 5.15.0-320.202.8.4.el8uek
  • 5.15.0-320.202.8.5.el8uek
  • 5.15.0-318.199.3.6.el8uek
  • 5.15.0-321.202.5.el8uek
  • 5.15.0-321.202.5.1.el8uek
  • 5.15.0-321.202.5.2.el8uek
  • 5.15.0-321.202.5.3.el8uek
  • 5.15.0-322.203.3.2.el8uek
  • 5.15.0-322.203.3.3.el8uek
  • 5.15.0-322.203.3.4.el8uek
  • 5.15.0-322.203.3.4.5.el8uek
  • 5.15.0-308.179.6.18.el8uek
  • 5.15.0-318.199.3.7.el8uek
  • 5.15.0-322.203.3.5.el8uek
  • 5.15.0-322.203.3.4.1.el8uek
  • 5.15.0-323.211.3.3.el8uek
  • 5.15.0-323.211.3.4.el8uek
  • 5.15.0-308.179.6.19.el8uek
  • 5.15.0-323.211.3.5.el8uek
Oracle Linux 9 UEK 7 Released
112 kernels
  • 5.15.0-101.103.2.1.el9uek
  • 5.15.0-8.91.4.1.el9uek
  • 5.15.0-7.86.6.1.el9uek
  • 5.15.0-5.76.5.1.el9uek
  • 5.15.0-6.80.3.1.el9uek
  • 5.15.0-3.60.5.1.el9uek
  • 5.15.0-0.30.20.el9uek
  • 5.15.0-100.96.32.el9uek
  • 5.15.0-1.43.4.2.el9uek
  • 5.15.0-2.52.3.el9uek
  • 5.15.0-4.70.5.2.el9uek
  • 5.15.0-1.43.4.1.el9uek
  • 5.15.0-0.30.20.1.el9uek
  • 5.15.0-102.110.5.el9uek
  • 5.15.0-102.110.5.1.el9uek
  • 5.15.0-103.114.4.el9uek
  • 5.15.0-104.119.4.2.el9uek
  • 5.15.0-0.30.19.el9uek
  • 5.15.0-105.125.6.2.el9uek
  • 5.15.0-105.125.6.2.1.el9uek
  • 5.15.0-105.125.6.2.2.el9uek
  • 5.15.0-106.131.4.el9uek
  • 5.15.0-200.131.27.el9uek
  • 5.15.0-200.131.27.1.el9uek
  • 5.15.0-201.135.6.el9uek
  • 5.15.0-202.135.2.el9uek
  • 5.15.0-203.146.5.1.el9uek
  • 5.15.0-204.147.6.2.el9uek
  • 5.15.0-204.147.6.3.el9uek
  • 5.15.0-205.149.5.1.el9uek
  • 5.15.0-205.149.5.4.el9uek
  • 5.15.0-206.153.7.el9uek
  • 5.15.0-206.153.7.1.el9uek
  • 5.15.0-207.156.6.el9uek
  • 5.15.0-208.159.3.el9uek
  • 5.15.0-208.159.3.2.el9uek
  • 5.15.0-209.161.7.el9uek
  • 5.15.0-209.161.7.1.el9uek
  • 5.15.0-209.161.7.2.el9uek
  • 5.15.0-210.163.7.el9uek
  • 5.15.0-300.163.18.el9uek
  • 5.15.0-300.163.18.1.el9uek
  • 5.15.0-300.163.18.1.1.el9uek
  • 5.15.0-301.163.5.2.el9uek
  • 5.15.0-302.167.6.el9uek
  • 5.15.0-300.163.18.7.el9uek
  • 5.15.0-302.167.6.1.el9uek
  • 5.15.0-303.171.5.2.el9uek
  • 5.15.0-303.171.5.2.1.el9uek
  • 5.15.0-304.171.4.el9uek
  • 5.15.0-304.171.4.1.el9uek
  • 5.15.0-304.171.4.3.el9uek
  • 5.15.0-303.171.5.2.2.el9uek
  • 5.15.0-305.176.4.el9uek
  • 5.15.0-306.177.4.el9uek
  • 5.15.0-306.177.4.1.el9uek
  • 5.15.0-307.178.5.el9uek
  • 5.15.0-308.179.6.el9uek
  • 5.15.0-308.179.6.2.el9uek
  • 5.15.0-308.179.6.3.el9uek
  • 5.15.0-309.180.4.el9uek
  • 5.15.0-308.179.6.7.el9uek
  • 5.15.0-309.180.4.2.el9uek
  • 5.15.0-308.179.6.11.el9uek
  • 5.15.0-310.184.5.2.el9uek
  • 5.15.0-310.184.5.3.el9uek
  • 5.15.0-311.185.9.el9uek
  • 5.15.0-308.179.6.14.el9uek
  • 5.15.0-312.187.5.el9uek
  • 5.15.0-312.187.5.1.el9uek
  • 5.15.0-312.187.5.2.el9uek
  • 5.15.0-312.187.5.3.el9uek
  • 5.15.0-308.179.6.16.el9uek
  • 5.15.0-313.189.5.1.el9uek
  • 5.15.0-313.189.5.2.el9uek
  • 5.15.0-313.189.5.3.el9uek
  • 5.15.0-314.193.5.3.el9uek
  • 5.15.0-314.193.5.4.el9uek
  • 5.15.0-314.193.5.5.el9uek
  • 5.15.0-315.196.5.1.el9uek
  • 5.15.0-315.196.5.2.el9uek
  • 5.15.0-316.196.4.1.el9uek
  • 5.15.0-316.196.4.2.el9uek
  • 5.15.0-317.197.5.1.el9uek
  • 5.15.0-317.197.5.2.el9uek
  • 5.15.0-318.199.3.2.el9uek
  • 5.15.0-318.199.3.2.1.el9uek
  • 5.15.0-319.201.4.2.el9uek
  • 5.15.0-319.201.4.3.el9uek
  • 5.15.0-319.201.4.4.el9uek
  • 5.15.0-319.201.4.6.el9uek
  • 5.15.0-320.202.8.2.el9uek
  • 5.15.0-320.202.8.3.el9uek
  • 5.15.0-320.202.8.4.el9uek
  • 5.15.0-320.202.8.5.el9uek
  • 5.15.0-318.199.3.6.el9uek
  • 5.15.0-321.202.5.el9uek
  • 5.15.0-321.202.5.1.el9uek
  • 5.15.0-321.202.5.2.el9uek
  • 5.15.0-321.202.5.3.el9uek
  • 5.15.0-322.203.3.2.el9uek
  • 5.15.0-322.203.3.3.el9uek
  • 5.15.0-322.203.3.4.el9uek
  • 5.15.0-322.203.3.4.5.el9uek
  • 5.15.0-308.179.6.18.el9uek
  • 5.15.0-318.199.3.7.el9uek
  • 5.15.0-322.203.3.5.el9uek
  • 5.15.0-322.203.3.4.1.el9uek
  • 5.15.0-323.211.3.3.el9uek
  • 5.15.0-323.211.3.4.el9uek
  • 5.15.0-308.179.6.19.el9uek
  • 5.15.0-323.211.3.5.el9uek
Ubuntu 24.04 Planned —
Ubuntu 24.04 AWS Planned —
Ubuntu 26.04 Will Not Fix —