ksmbd: fix reference count leak in smb_check_perm_dacl()
In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix reference count leak in smb_check_perm_dacl() The issue happens in a specific path in smb_check_perm_dacl(). When "id" and "uid" have the same value, the function simply jumps out of the loop without decrementing the reference count of the object "posix_acls", which is increased by get_acl() earlier. This may result in memory leaks. Fix it by decreasing the reference count of "posix_acls" before jumping to label "check_access_bits".
- Published
- Feb 26, 2025
- Updated
- Jun 17, 2026
- EPSS
- 0.3% · 16th 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 · 0.3%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
Affected 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 kernel5.15 and later · before 5.15.47
- linux linux kernel5.16 and later · before 5.17.15
- linux linux kernel5.18 and later · before 5.18.4
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
- 5.15affected
- 777cad1604d68ed4379ec899d1f7d2f6a29f01f0 and later · before cf824b95c12a1abacadbc2d069931963221a3414affected · git
- 777cad1604d68ed4379ec899d1f7d2f6a29f01f0 and later · before 248d71b440aef829f5cc5f6545ca113ef5062900affected · git
- 777cad1604d68ed4379ec899d1f7d2f6a29f01f0 and later · before 9758a6653c27867d810de02b4e5697163dda9883affected · git
- 777cad1604d68ed4379ec899d1f7d2f6a29f01f0 and later · before d21a580dafc69aa04f46e6099616146a536b0724affected · git
- before 5.15not affected · semver
- 5.15.47 and later · up to and including 5.15.*not affected · semver
- 5.17.15 and later · up to and including 5.17.*not affected · semver
- 5.18.4 and later · up to and including 5.18.*not affected · semver
- 5.19 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:12 | linux | before 5.18.5-1 | 5.18.5-1 |
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 | 248d71b440aef829f5cc5f6545ca113ef5062900 | Vendor (CNA) |
| Linux Linux | 9758a6653c27867d810de02b4e5697163dda9883 | Vendor (CNA) |
| Linux Linux | cf824b95c12a1abacadbc2d069931963221a3414 | Vendor (CNA) |
| Linux Linux | d21a580dafc69aa04f46e6099616146a536b0724 | Vendor (CNA) |
| debian:linux | 5.18.5-1 · 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.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for all 385,000+ vulnerabilities; 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 helpChange log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- git.kernel.org/stable/c/248d71b440aef829f5cc5f6545ca113ef5062900
- git.kernel.org/stable/c/9758a6653c27867d810de02b4e5697163dda9883
- git.kernel.org/stable/c/cf824b95c12a1abacadbc2d069931963221a3414
- git.kernel.org/stable/c/d21a580dafc69aa04f46e6099616146a536b0724
Vendor advisories and official records. Exploit/PoC links are deliberately left out.