mm: do file ownership checks with the proper mount idmap
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.
- Published
- Jul 25, 2026
- Updated
- Aug 23, 2026
- EPSS
- 0.2% · 5th percentile
- CWE
- —
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Report tools
Action score
22
Monitor
Low priority for now.
- CVSS
- 22 / 40 · 5.5 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.2%
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for the hundreds of thousands of vulnerabilities in the database; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpAffected systems
| Vendor | Product | CPE |
|---|---|---|
| linux | linux kernel | cpe:2.3:o:linux:linux_kernel |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- linux linux kernel5.12 and later · before 6.6.145
- linux linux kernel6.7 and later · before 6.12.96
- linux linux kernel6.13 and later · before 6.18.39
- linux linux kernel6.19 and later · before 7.1.4
- linux linux kernel7.2
Versions reported by the vendor
Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.
Linux Linux
- 5.12affected
- 9caccd41541a6f7d6279928d9f971f6642c361af and later · before 7368bec565bac3e536cd43579dbde1e715e6ba61affected · git
- 9caccd41541a6f7d6279928d9f971f6642c361af and later · before b2f3d94ea310bea9d36d53e9d9b3f45e86c1d893affected · git
- 9caccd41541a6f7d6279928d9f971f6642c361af and later · before 744b23aa430d52f5c8e4dbff7d71496d6643bed2affected · git
- 9caccd41541a6f7d6279928d9f971f6642c361af and later · before 8344bdf0629457e532797b42d9d2bbf2a2900bbfaffected · git
- 9caccd41541a6f7d6279928d9f971f6642c361af and later · before 5c942ad7df75925ee166e7f0fb36892d8dde376baffected · git
- 9caccd41541a6f7d6279928d9f971f6642c361af and later · before 04ba248d02d9eaa3d9077b00a6134caa75fa3e90affected · git
- 9caccd41541a6f7d6279928d9f971f6642c361af and later · before e187bc02f8fa4226d62814592cf064ee4557c470affected · git
- before 5.12not affected · semver
- 5.15.217 and later · up to and including 5.15.*not affected · semver
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:12 | linux | before 6.1.187-1 | 6.1.187-1 |
| Debian:12 | linux-6.12 | before 6.12.100-1~deb12u1 | 6.12.100-1~deb12u1 |
| Debian:13 | linux | before 6.12.96-1 | 6.12.96-1 |
| Debian:14 | linux | before 7.1.4-1 | 7.1.4-1 |
Same product
linux: all recordsOther highest-scoring records for the same primary product.
- CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe KEV89Now
- CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV85Now
- CVE-2016-5195Race condition in mm/gup.c in the Linux kernel 2.x through 4.x before 4.8.3 allows local users to gain privileges by leveraging incorrect haKEV83Now
- CVE-2019-13272In the Linux kernel before 5.1.17, ptrace_link in kernel/ptrace.c mishandles the recording of the credentials of a process that wants to creKEV77This week
- CVE-2013-6282The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the v6k and v7 ARM platforms do not validate certain addKEV77This week
- CVE-2013-2094The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9 uses an incorrect integer data type, which allows loKEV77This week
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| Linux Linux | 04ba248d02d9eaa3d9077b00a6134caa75fa3e90 | Vendor (CNA) |
| Linux Linux | 5c942ad7df75925ee166e7f0fb36892d8dde376b | Vendor (CNA) |
| Linux Linux | 7368bec565bac3e536cd43579dbde1e715e6ba61 | Vendor (CNA) |
| Linux Linux | 744b23aa430d52f5c8e4dbff7d71496d6643bed2 | Vendor (CNA) |
| Linux Linux | 8344bdf0629457e532797b42d9d2bbf2a2900bbf | Vendor (CNA) |
| Linux Linux | b2f3d94ea310bea9d36d53e9d9b3f45e86c1d893 | Vendor (CNA) |
| Linux Linux | e187bc02f8fa4226d62814592cf064ee4557c470 | Vendor (CNA) |
| azl3 kernel 6.6.144.1-1 on Azure Linux 3.0 | 6.6.145.2-1 · CBL-Mariner Releases | Microsoft (MSRC) |
| debian:linux | 6.1.187-1 · Debian:12 | Package registry (OSV) |
| debian:linux-6.12 | 6.12.100-1~deb12u1 · Debian:12 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Someone with local access to the system can trigger it.
- A low-privileged account is enough.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- none
- Integrity
- none
- Availability
- high · the service can be disrupted
- Attack vector
- Local
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- None
- Integrity impact
- None
- Availability impact
- High
Weakness class (CWE)
—
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- git.kernel.org/stable/c/04ba248d02d9eaa3d9077b00a6134caa75fa3e90
- git.kernel.org/stable/c/5c942ad7df75925ee166e7f0fb36892d8dde376b
- git.kernel.org/stable/c/7368bec565bac3e536cd43579dbde1e715e6ba61
- git.kernel.org/stable/c/744b23aa430d52f5c8e4dbff7d71496d6643bed2
- git.kernel.org/stable/c/8344bdf0629457e532797b42d9d2bbf2a2900bbf
- git.kernel.org/stable/c/b2f3d94ea310bea9d36d53e9d9b3f45e86c1d893
- git.kernel.org/stable/c/e187bc02f8fa4226d62814592cf064ee4557c470
Vendor advisories and official records. Exploit/PoC links are deliberately left out.