f2fs: fix KMSAN uninit-value in extent_info usage
In the Linux kernel, the following vulnerability has been resolved: f2fs: fix KMSAN uninit-value in extent_info usage KMSAN reported a use of uninitialized value in `__is_extent_mergeable()` and `__is_back_mergeable()` via the read extent tree path. The root cause is that `get_read_extent_info()` only initializes three fields (`fofs`, `blk`, `len`) of `struct extent_info`, leaving the remaining fields uninitialized. This leads to undefined behavior when those fields are accessed later, especially during extent merging. Fix it by zero-initializing the `extent_info` struct before population.
- Published
- Aug 19, 2025
- Updated
- Aug 5, 2026
- EPSS
- 0.2% · 6th percentile
- CWE
- CWE-908
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Report tools
Action score
31
Monitor
Low priority for now.
- CVSS
- 31 / 40 · 7.8 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.2%
CNA vs NVD score
- NVD
- 7.8
- CNA · Linux
- 7.8
- agree
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
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 |
| debian | debian linux | cpe:2.3:o:debian:debian_linux |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- debian debian linux11.0
- linux linux kernel5.16 and later · before 6.1.148
- linux linux kernel6.2 and later · before 6.6.102
- linux linux kernel5.15 and later · before 5.15.190
- linux linux kernel6.13 and later · before 6.15.10
- linux linux kernel6.16 and later · before 6.16.1
- linux linux kernel6.7 and later · before 6.12.42
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
- 94afd6d6e5253179c9b891d02081cc8355a11768 and later · before 08e8ab00a6d20d5544c932ee85a297d833895141affected · git
- 94afd6d6e5253179c9b891d02081cc8355a11768 and later · before e68b751ec2b15d866967812c57cfdfc1eba6a269affected · git
- 94afd6d6e5253179c9b891d02081cc8355a11768 and later · before dabfa3952c8e6bfe6414dbf32e8b6c5f349dc898affected · git
- 94afd6d6e5253179c9b891d02081cc8355a11768 and later · before 44a79437309e0ee2276ac17aaedc71253af253a8affected · git
- 94afd6d6e5253179c9b891d02081cc8355a11768 and later · before cc1615d5aba4f396cf412579928539a2b124c8a0affected · git
- 94afd6d6e5253179c9b891d02081cc8355a11768 and later · before 01b6f5955e0008af6bc3a181310d2744bb349800affected · git
- 94afd6d6e5253179c9b891d02081cc8355a11768 and later · before 154467f4ad033473e5c903a03e7b9bca7df9a0faaffected · git
- before 5.15not affected · semver
- 5.15.190 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 6.1.148-1 | 6.1.148-1 |
| Debian:13 | linux | before 6.12.43-1 | 6.12.43-1 |
| Debian:14 | linux | before 6.16.3-1 | 6.16.3-1 |
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 | 01b6f5955e0008af6bc3a181310d2744bb349800 | Vendor (CNA) |
| Linux Linux | 08e8ab00a6d20d5544c932ee85a297d833895141 | Vendor (CNA) |
| Linux Linux | 154467f4ad033473e5c903a03e7b9bca7df9a0fa | Vendor (CNA) |
| Linux Linux | 44a79437309e0ee2276ac17aaedc71253af253a8 | Vendor (CNA) |
| Linux Linux | cc1615d5aba4f396cf412579928539a2b124c8a0 | Vendor (CNA) |
| Linux Linux | dabfa3952c8e6bfe6414dbf32e8b6c5f349dc898 | Vendor (CNA) |
| Linux Linux | e68b751ec2b15d866967812c57cfdfc1eba6a269 | Vendor (CNA) |
| debian:linux | 6.1.148-1 · 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.
- CVE-2024-50302274 days apartHID: core: zero-initialize the report bufferKEV52Plan
- CVE-2026-52989309 days apartnvmet-tcp: propagate nvmet_tcp_build_pdu_iovec() errors to its callers39Monitor
- CVE-2024-47685302 days apartnetfilter: nf_reject_ipv6: fix nf_reject_ip6_tcphdr_put()36Monitor
- CVE-2026-53225310 days apartsctp: fix uninit-value in __sctp_rcv_asconf_lookup()36Monitor
- CVE-2026-53170310 days apartaccel/ethosu: reject DMA commands with uninitialized length35Monitor
- CVE-2026-43139260 days apartxfrm6: fix uninitialized saddr in xfrm6_get_saddr()34Monitor
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
- high · data can be read
- Integrity
- high · data or configuration can be modified
- Availability
- high · the service can be disrupted
- Attack vector
- Local
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- High
Weakness class (CWE)
CWE-908 · Use of Uninitialized ResourceCVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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/01b6f5955e0008af6bc3a181310d2744bb349800
- git.kernel.org/stable/c/08e8ab00a6d20d5544c932ee85a297d833895141
- git.kernel.org/stable/c/154467f4ad033473e5c903a03e7b9bca7df9a0fa
- git.kernel.org/stable/c/44a79437309e0ee2276ac17aaedc71253af253a8
- git.kernel.org/stable/c/cc1615d5aba4f396cf412579928539a2b124c8a0
- git.kernel.org/stable/c/dabfa3952c8e6bfe6414dbf32e8b6c5f349dc898
- git.kernel.org/stable/c/e68b751ec2b15d866967812c57cfdfc1eba6a269
- lists.debian.org/debian-lts-announce/2025/10/msg00008.html
Vendor advisories and official records. Exploit/PoC links are deliberately left out.