btrfs: fix race setting file private on concurrent lseek using same fd
Noroxi assessment
Priority: Monitor (action score 28/100)
- The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
- Probability of exploitation in the next 30 days: 0.16% (FIRST EPSS).
- Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. Special conditions such as timing or configuration are required.
- Fixed version: Linux Linux 33d1310d4496e904123dab9c28b2d8d2c1800f97, 7ee85f5515e86a4e2a2f51969795920733912bad, a412ca489ac27b9d0e603499315b7139c948130d.
- Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).
Low priority for now. Upgrade to Linux Linux 33d1310d4496e904123dab9c28b2d8d2c1800f97, 7ee85f5515e86a4e2a2f51969795920733912bad, a412ca489ac27b9d0e603499315b7139c948130d or later.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
In the Linux kernel, the following vulnerability has been resolved: btrfs: fix race setting file private on concurrent lseek using same fd When doing concurrent lseek(2) system calls against the same file descriptor, using multiple threads belonging to the same process, we have a short time window where a race happens and can result in a memory leak. The race happens like this: 1) A program opens a file descriptor for a file and then spawns two threads (with the pthreads library for example), lets call them task A and task B; 2) Task A calls lseek with SEEK_DATA or SEEK_HOLE and ends up at file.c:find_desired_extent() while holding a read lock on the inode; 3) At the start of find_desired_extent(), it extracts the file's private_data pointer into a local variable named 'private', which has a value of NULL; 4) Task B also calls lseek with SEEK_DATA or SEEK_HOLE, locks the inode in shared mode and enters file.c:find_desired_extent(), where it also extracts file->private_data into its local variable 'private', which has a NULL value; 5) Because it saw a NULL file private, task A allocates a private structure and assigns to the file structure; 6) Task B also saw a NULL file private so it also allocates its own file private and then assigns it to the same file structure, since both tasks are using the same file descriptor. At this point we leak the private structure allocated by task A. Besides the memory leak, there's also the detail that both tasks end up using the same cached state record in the private structure (struct btrfs_file_private::llseek_cached_state), which can result in a use-after-free problem since one task can free it while the other is still using it (only one task took a reference count on it). Also, sharing the cached state is not a good idea since it could result in incorrect results in the future - right now it should not be a problem because it end ups being used only in extent-io-tree.c:count_range_bits() where we do range validation before using the cached state. Fix this by protecting the private assignment and check of a file while holding the inode's spinlock and keep track of the task that allocated the private, so that it's used only by that task in order to prevent user-after-free issues with the cached state record as well as potentially using it incorrectly in the future.
- Published
- Oct 21, 2024
- Updated
- Aug 5, 2026
- EPSS
- 0.2% · 5th percentile
- CWE
- CWE-362
Report tools
Action score
28
Monitor
Low priority for now.
- CVSS
- 28 / 40 · 7.0 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.2%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- 7.0
- CNA · Linux
- 7.8
- 0.8 point gap
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
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Noroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
| 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 kernel6.2 and later · before 6.6.54
- linux linux kernel6.7 and later · before 6.10.13
- linux linux kernel6.11 and later · before 6.11.2
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
- 6.2affected
- 3c32c7212f1639471ec0197ff1179b8ef2e0f3d3 and later · before f56a6d9c267ec7fa558ede7755551c047b1034cdaffected · git
- 3c32c7212f1639471ec0197ff1179b8ef2e0f3d3 and later · before a412ca489ac27b9d0e603499315b7139c948130daffected · git
- 3c32c7212f1639471ec0197ff1179b8ef2e0f3d3 and later · before 33d1310d4496e904123dab9c28b2d8d2c1800f97affected · git
- 3c32c7212f1639471ec0197ff1179b8ef2e0f3d3 and later · before 7ee85f5515e86a4e2a2f51969795920733912badaffected · git
- before 6.2not affected · semver
- 6.6.54 and later · up to and including 6.6.*not affected · semver
- 6.10.13 and later · up to and including 6.10.*not affected · semver
- 6.11.2 and later · up to and including 6.11.*not affected · semver
- 6.12 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 6.11.2-1 | 6.11.2-1 |
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 | 33d1310d4496e904123dab9c28b2d8d2c1800f97 | Vendor (CNA) |
| Linux Linux | 7ee85f5515e86a4e2a2f51969795920733912bad | Vendor (CNA) |
| Linux Linux | a412ca489ac27b9d0e603499315b7139c948130d | Vendor (CNA) |
| Linux Linux | f56a6d9c267ec7fa558ede7755551c047b1034cd | Vendor (CNA) |
| debian:linux | 6.11.2-1 · 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).
National notice (Türkiye Cybersecurity Directorate / USOM)
Official security notices citing this record; remediation advice is on the agency's page.
- TR-24-1743 · Oct 22, 2024(Linux Kernel Güvenlik Bildirimi)
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.
- Special conditions such as timing or configuration are required.
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
- High
- Privileges required
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- High
Weakness class (CWE)
CWE-362 · Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')CVSS vector
CVSS:3.1/AV:L/AC:H/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.
Attack patterns (CAPEC)
ATT&CK techniques
—
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (3 more)Show less
Vendor advisories and official records. Exploit/PoC links are deliberately left out.