tracing: Have trace_event_file have ref counters
Noroxi assessment
Priority: Monitor (action score 22/100)
- 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: 0.22% (FIRST EPSS).
- 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.
- Fixed version: Linux Linux 2c9de867ca285c397cd71af703763fe416265706, 2fa74d29fc1899c237d51bf9a6e132ea5c488976, 5.10.202.
- Severity is disputed: the assigning authority (CNA) scores it 7.8, NVD 5.5.
Low priority for now. Upgrade to Linux Linux 2c9de867ca285c397cd71af703763fe416265706, 2fa74d29fc1899c237d51bf9a6e132ea5c488976, 5.10.202 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: tracing: Have trace_event_file have ref counters The following can crash the kernel: # cd /sys/kernel/tracing # echo 'p:sched schedule' > kprobe_events # exec 5>>events/kprobes/sched/enable # > kprobe_events # exec 5>&- The above commands: 1. Change directory to the tracefs directory 2. Create a kprobe event (doesn't matter what one) 3. Open bash file descriptor 5 on the enable file of the kprobe event 4. Delete the kprobe event (removes the files too) 5. Close the bash file descriptor 5 The above causes a crash! BUG: kernel NULL pointer dereference, address: 0000000000000028 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: 0000 [#1] PREEMPT SMP PTI CPU: 6 PID: 877 Comm: bash Not tainted 6.5.0-rc4-test-00008-g2c6b6b1029d4-dirty #186 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 RIP: 0010:tracing_release_file_tr+0xc/0x50 What happens here is that the kprobe event creates a trace_event_file "file" descriptor that represents the file in tracefs to the event. It maintains state of the event (is it enabled for the given instance?). Opening the "enable" file gets a reference to the event "file" descriptor via the open file descriptor. When the kprobe event is deleted, the file is also deleted from the tracefs system which also frees the event "file" descriptor. But as the tracefs file is still opened by user space, it will not be totally removed until the final dput() is called on it. But this is not true with the event "file" descriptor that is already freed. If the user does a write to or simply closes the file descriptor it will reference the event "file" descriptor that was just freed, causing a use-after-free bug. To solve this, add a ref count to the event "file" descriptor as well as a new flag called "FREED". The "file" will not be freed until the last reference is released. But the FREE flag will be set when the event is removed to prevent any more modifications to that event from happening, even if there's still a reference to the event "file" descriptor.
- Published
- May 21, 2024
- Updated
- Aug 5, 2026
- EPSS
- 0.2% · 12th percentile
- CWE
- CWE-476
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%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- 5.5
- CNA · Linux
- 7.8
- 2.3 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 kernel5.4.258 and later · before 5.4.262
- linux linux kernel5.10.198 and later · before 5.10.202
- linux linux kernel5.15.134 and later · before 5.15.140
- linux linux kernel6.1.55 and later · before 6.1.64
- linux linux kernel6.5.5 and later · before 6.5.13
- linux linux kernel6.6 and later · before 6.6.1
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
- 6.6affected
- e6807c873d8791ae5a5186ad05ec66cab926539a and later · before 961c4511c7578d6b8f39118be919016ec3db1c1eaffected · git
- 407bf1c140f0757706c0b28604bcc90837d45ce2 and later · before a98172e36e5f1b3d29ad71fade2d611cfcc2fe6faffected · git
- fa6d449e4d024d8c17f4288e0567d28ace69415c and later · before cbc7c29dff0fa18162f2a3889d82eeefd67305e0affected · git
- a46bf337a20f9edd3c8041b025639842280d0575 and later · before 2fa74d29fc1899c237d51bf9a6e132ea5c488976affected · git
- 9beec04370132a7a6cd1aa9897f6fffc6262ff28 and later · before 2c9de867ca285c397cd71af703763fe416265706affected · git
- f5ca233e2e66dc1c249bf07eefa37e34a6c9346a and later · before 9034c87d61be8cff989017740a91701ac8195a1daffected · git
- f5ca233e2e66dc1c249bf07eefa37e34a6c9346a and later · before bb32500fb9b78215e4ef6ee8b4345c5f5d7eafb4affected · git
- 5.4.258 and later · before 5.4.262affected · semver
- 5.10.198 and later · before 5.10.202affected · 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 6.1.64-1 | 6.1.64-1 |
| Debian:13 | linux | before 6.6.8-1 | 6.6.8-1 |
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 | 2c9de867ca285c397cd71af703763fe416265706 | Vendor (CNA) |
| Linux Linux | 2fa74d29fc1899c237d51bf9a6e132ea5c488976 | Vendor (CNA) |
| Linux Linux | 5.10.202 | Vendor (CNA) |
| Linux Linux | 5.15.140 | Vendor (CNA) |
| Linux Linux | 5.4.262 | Vendor (CNA) |
| Linux Linux | 6.1.64 | Vendor (CNA) |
| Linux Linux | 6.5.13 | Vendor (CNA) |
| Linux Linux | 9034c87d61be8cff989017740a91701ac8195a1d | Vendor (CNA) |
| Linux Linux | 961c4511c7578d6b8f39118be919016ec3db1c1e | Vendor (CNA) |
| Linux Linux | a98172e36e5f1b3d29ad71fade2d611cfcc2fe6f | Vendor (CNA) |
| Linux Linux | bb32500fb9b78215e4ef6ee8b4345c5f5d7eafb4 | Vendor (CNA) |
| Linux Linux | cbc7c29dff0fa18162f2a3889d82eeefd67305e0 | Vendor (CNA) |
| debian:linux | 6.1.64-1 · 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)
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
Show all references (6 more)Show less
- git.kernel.org/stable/c/2fa74d29fc1899c237d51bf9a6e132ea5c488976
- git.kernel.org/stable/c/9034c87d61be8cff989017740a91701ac8195a1d
- git.kernel.org/stable/c/961c4511c7578d6b8f39118be919016ec3db1c1e
- git.kernel.org/stable/c/a98172e36e5f1b3d29ad71fade2d611cfcc2fe6f
- git.kernel.org/stable/c/bb32500fb9b78215e4ef6ee8b4345c5f5d7eafb4
- git.kernel.org/stable/c/cbc7c29dff0fa18162f2a3889d82eeefd67305e0
Vendor advisories and official records. Exploit/PoC links are deliberately left out.