ceph: fix NULL pointer dereference in ceph_mds_auth_match()
In the Linux kernel, the following vulnerability has been resolved: ceph: fix NULL pointer dereference in ceph_mds_auth_match() The CephFS kernel client has regression starting from 6.18-rc1. We have issue in ceph_mds_auth_match() if fs_name == NULL: const char fs_name = mdsc->fsc->mount_options->mds_namespace; ... if (auth->match.fs_name && strcmp(auth->match.fs_name, fs_name)) { / fsname mismatch, try next one */ return 0; } Patrick Donnelly suggested that: In summary, we should definitely start decoding `fs_name` from the MDSMap and do strict authorizations checks against it. Note that the `-o mds_namespace=foo` should only be used for selecting the file system to mount and nothing else. It's possible no mds_namespace is specified but the kernel will mount the only file system that exists which may have name "foo". This patch reworks ceph_mdsmap_decode() and namespace_equals() with the goal of supporting the suggested concept. Now struct ceph_mdsmap contains m_fs_name field that receives copy of extracted FS name by ceph_extract_encoded_string(). For the case of "old" CephFS file systems, it is used "cephfs" name. [ idryomov: replace redundant %*pE with %s in ceph_mdsmap_decode(), get rid of a series of strlen() calls in ceph_namespace_match(), drop changes to namespace_equals() body to avoid treating empty mds_namespace as equal, drop changes to ceph_mdsc_handle_fsmap() as namespace_equals() isn't an equivalent substitution there ]
- Published
- Feb 14, 2026
- Updated
- Jun 17, 2026
- EPSS
- 0.1% · 1th percentile
- CWE
- CWE-476
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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 · 0.1%
Noroxi analysis
No Noroxi analysis for this record yet
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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 kernel6.12.58 and later · before 6.12.70
- linux linux kernel6.17.8 and later · before 6.18.10
- linux linux kernel6.19
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
- ca3da8b27ab9a0923ad477447cfb8fc7f4b4c523, 6.18affected
- 07640d34a781bb2e39020a39137073c03c4aa932 and later · before c6f8326f26bd20d648d9a55afd68148d1b6afe28affected · git
- 22c73d52a6d05c5a2053385c0d6cd9984732799d and later · before 57b36ffc8881dd455d875f85c105901974af2130affected · git
- 22c73d52a6d05c5a2053385c0d6cd9984732799d and later · before 7987cce375ac8ce98e170a77aa2399f2cf6eb99faffected · git
- 6.12.58 and later · before 6.12.70affected · semver
- 6.17.8 and later · before 6.18affected · semver
- before 6.18not affected · semver
- 6.12.70 and later · up to and including 6.12.*not affected · semver
- 6.18.10 and later · up to and including 6.18.*not affected · semver
- 6.19 and laternot affected · original_commit_for_fix
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:13 | linux | before 6.12.73-1 | 6.12.73-1 |
| Debian:14 | linux | before 6.18.10-1 | 6.18.10-1 |
Same product
linux: all recordsOther highest-scoring records for the same primary product.
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- 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 | 57b36ffc8881dd455d875f85c105901974af2130 | Vendor (CNA) |
| Linux Linux | 6.12.70 | Vendor (CNA) |
| Linux Linux | 6.18 | Vendor (CNA) |
| Linux Linux | 7987cce375ac8ce98e170a77aa2399f2cf6eb99f | Vendor (CNA) |
| Linux Linux | c6f8326f26bd20d648d9a55afd68148d1b6afe28 | Vendor (CNA) |
| debian:linux | 6.12.73-1 · Debian:13 | 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)
CWE-476 · NULL Pointer DereferenceCVSS 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/57b36ffc8881dd455d875f85c105901974af2130
- git.kernel.org/stable/c/7987cce375ac8ce98e170a77aa2399f2cf6eb99f
- git.kernel.org/stable/c/c6f8326f26bd20d648d9a55afd68148d1b6afe28
Vendor advisories and official records. Exploit/PoC links are deliberately left out.