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NVD / CVE Program· CNA Linux

CVE-2024-49870: cachefiles: fix dentry leak in cachefiles_open_file()

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: 0.23% (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 7fa2382f97421978514a419c93054eca69f5247b, c7d10fa7d7691558ff967668494672415f5fa151, d32ff64c872d7e08e893c32ba6a2374583444410; azl3 kernel 6.6.51.1-5 on Azure Linux 3.0 6.6.57.1-2; azl3 kernel 6.6.57.1-2 on Azure Linux 3.0 6.6.57.1-2.

Low priority for now. Upgrade to Linux Linux 7fa2382f97421978514a419c93054eca69f5247b, c7d10fa7d7691558ff967668494672415f5fa151, d32ff64c872d7e08e893c32ba6a2374583444410; azl3 kernel 6.6.51.1-5 on Azure Linux 3.0 6.6.57.1-2; azl3 kernel 6.6.57.1-2 on Azure Linux 3.0 6.6.57.1-2 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: cachefiles: fix dentry leak in cachefiles_open_file() A dentry leak may be caused when a lookup cookie and a cull are concurrent: P1 | P2 ----------------------------------------------------------- cachefiles_lookup_cookie cachefiles_look_up_object lookup_one_positive_unlocked // get dentry cachefiles_cull inode->i_flags |= S_KERNEL_FILE; cachefiles_open_file cachefiles_mark_inode_in_use __cachefiles_mark_inode_in_use can_use = false if (!(inode->i_flags & S_KERNEL_FILE)) can_use = true return false return false // Returns an error but doesn't put dentry After that the following WARNING will be triggered when the backend folder is umounted: ================================================================== BUG: Dentry 000000008ad87947{i=7a,n=Dx_1_1.img} still in use (1) [unmount of ext4 sda] WARNING: CPU: 4 PID: 359261 at fs/dcache.c:1767 umount_check+0x5d/0x70 CPU: 4 PID: 359261 Comm: umount Not tainted 6.6.0-dirty #25 RIP: 0010:umount_check+0x5d/0x70 Call Trace: <TASK> d_walk+0xda/0x2b0 do_one_tree+0x20/0x40 shrink_dcache_for_umount+0x2c/0x90 generic_shutdown_super+0x20/0x160 kill_block_super+0x1a/0x40 ext4_kill_sb+0x22/0x40 deactivate_locked_super+0x35/0x80 cleanup_mnt+0x104/0x160 ================================================================== Whether cachefiles_open_file() returns true or false, the reference count obtained by lookup_positive_unlocked() in cachefiles_look_up_object() should be released. Therefore release that reference count in cachefiles_look_up_object() to fix the above issue and simplify the code.

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
Oct 21, 2024
Updated
Jun 17, 2026
EPSS
0.2% · 14th percentile

Report tools

JSON

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.

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.

Follow CVE-2024-49870

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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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.

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Affected 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.

VendorProduct
linuxlinux kernel

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • linux linux kernel5.17 and later · before 6.1.113
  • linux linux kernel6.2 and later · before 6.6.55
  • linux linux kernel6.7 and later · before 6.10.14
  • linux linux kernel6.11 and later · before 6.11.3
  • linux linux kernel6.12

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

    • 5.17affected
    • 1f08c925e7a38002bde509e66f6f891468848511 and later · before d32ff64c872d7e08e893c32ba6a2374583444410affected · git
    • 1f08c925e7a38002bde509e66f6f891468848511 and later · before c7d10fa7d7691558ff967668494672415f5fa151affected · git
    • 1f08c925e7a38002bde509e66f6f891468848511 and later · before e4a28489b310339b2b8187bec0a437709be551c1affected · git
    • 1f08c925e7a38002bde509e66f6f891468848511 and later · before 7fa2382f97421978514a419c93054eca69f5247baffected · git
    • 1f08c925e7a38002bde509e66f6f891468848511 and later · before da6ef2dffe6056aad3435e6cf7c6471c2a62187caffected · git
    • before 5.17not affected · semver
    • 6.1.113 and later · up to and including 6.1.*not affected · semver
    • 6.6.55 and later · up to and including 6.6.*not affected · semver
    • 6.10.14 and later · up to and including 6.10.*not affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.115-16.1.115-1
Debian:13linuxbefore 6.11.4-16.11.4-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
    90Now
  • 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 KEV
    89Now
  • CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
    85Now

Published before and after this one in the same product

  • ← EarlierCVE-2024-49868Oct 21, 2024 · btrfs: fix a NULL pointer dereference when failed to start a new trasacntion
    22Monitor
  • ← EarlierCVE-2024-49869Oct 21, 2024 · btrfs: send: fix buffer overflow detection when copying path to cache entry
    31Monitor
  • Later →CVE-2024-49871Oct 21, 2024 · Input: adp5589-keys - fix NULL pointer dereference
    22Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux7fa2382f97421978514a419c93054eca69f5247bVendor (CNA)
Linux Linuxc7d10fa7d7691558ff967668494672415f5fa151Vendor (CNA)
Linux Linuxd32ff64c872d7e08e893c32ba6a2374583444410Vendor (CNA)
Linux Linuxda6ef2dffe6056aad3435e6cf7c6471c2a62187cVendor (CNA)
Linux Linuxe4a28489b310339b2b8187bec0a437709be551c1Vendor (CNA)
azl3 kernel 6.6.51.1-5 on Azure Linux 3.06.6.57.1-2 · CBL-Mariner ReleasesMicrosoft (MSRC)
azl3 kernel 6.6.57.1-2 on Azure Linux 3.06.6.57.1-2 · CBL-Mariner ReleasesMicrosoft (MSRC)
debian:linux6.1.115-1 · Debian:12Package 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.

No history yet (it accumulates with the daily EPSS job).

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 researchers

Finders, 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-401 · Missing Release of Memory after Effective Lifetime

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.

Change log

  1. Fix✗ → ✓

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References

Show all references (5 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records