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NVD / CVE Program· CNA Linux

CVE-2024-26727: btrfs: do not ASSERT() if the newly created subvolume already got read

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 3f5d47eb163bceb1b9e613c9003bae5fefc0046f, 5.9, 5a172344bfdabb46458e03708735d7b1a918c468.
  • Mentioned 2 times in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 3f5d47eb163bceb1b9e613c9003bae5fefc0046f, 5.9, 5a172344bfdabb46458e03708735d7b1a918c468 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: do not ASSERT() if the newly created subvolume already got read [BUG] There is a syzbot crash, triggered by the ASSERT() during subvolume creation: assertion failed: !anon_dev, in fs/btrfs/disk-io.c:1319 ------------[ cut here ]------------ kernel BUG at fs/btrfs/disk-io.c:1319! invalid opcode: 0000 [#1] PREEMPT SMP KASAN RIP: 0010:btrfs_get_root_ref.part.0+0x9aa/0xa60 <TASK> btrfs_get_new_fs_root+0xd3/0xf0 create_subvol+0xd02/0x1650 btrfs_mksubvol+0xe95/0x12b0 __btrfs_ioctl_snap_create+0x2f9/0x4f0 btrfs_ioctl_snap_create+0x16b/0x200 btrfs_ioctl+0x35f0/0x5cf0 __x64_sys_ioctl+0x19d/0x210 do_syscall_64+0x3f/0xe0 entry_SYSCALL_64_after_hwframe+0x63/0x6b ---[ end trace 0000000000000000 ]--- [CAUSE] During create_subvol(), after inserting root item for the newly created subvolume, we would trigger btrfs_get_new_fs_root() to get the btrfs_root of that subvolume. The idea here is, we have preallocated an anonymous device number for the subvolume, thus we can assign it to the new subvolume. But there is really nothing preventing things like backref walk to read the new subvolume. If that happens before we call btrfs_get_new_fs_root(), the subvolume would be read out, with a new anonymous device number assigned already. In that case, we would trigger ASSERT(), as we really expect no one to read out that subvolume (which is not yet accessible from the fs). But things like backref walk is still possible to trigger the read on the subvolume. Thus our assumption on the ASSERT() is not correct in the first place. [FIX] Fix it by removing the ASSERT(), and just free the @anon_dev, reset it to 0, and continue. If the subvolume tree is read out by something else, it should have already get a new anon_dev assigned thus we only need to free the preallocated one.

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
Apr 3, 2024
Updated
Jun 17, 2026
EPSS
0.2% · 13th 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

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Follow CVE-2024-26727

When you'll hear from us

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  • 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
debiandebian linux

Affected versions

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

  • debian debian linux10.0
  • linux linux kernel5.11 and later · before 5.15.149
  • linux linux kernel5.16 and later · before 6.1.79
  • linux linux kernel5.9 and later · before 5.10.210
  • linux linux kernel6.7 and later · before 6.7.6
  • linux linux kernel6.2 and later · before 6.6.18
  • linux linux kernel6.8

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

    • 917d608fe375041eb7f29befa6a6d7fd3cf32dde, 5.9affected
    • 2dfb1e43f57dd3aeaa66f7cf05d068db2d4c8788 and later · before 3f5d47eb163bceb1b9e613c9003bae5fefc0046faffected · git
    • 2dfb1e43f57dd3aeaa66f7cf05d068db2d4c8788 and later · before e31546b0f34af21738c4ceac47d662c00ee6382faffected · git
    • 2dfb1e43f57dd3aeaa66f7cf05d068db2d4c8788 and later · before 66b317a2fc45b2ef66527ee3f8fa08fb5beab88daffected · git
    • 2dfb1e43f57dd3aeaa66f7cf05d068db2d4c8788 and later · before 833775656d447c545133a744a0ed1e189ce61430affected · git
    • 2dfb1e43f57dd3aeaa66f7cf05d068db2d4c8788 and later · before 5a172344bfdabb46458e03708735d7b1a918c468affected · git
    • 2dfb1e43f57dd3aeaa66f7cf05d068db2d4c8788 and later · before e03ee2fe873eb68c1f9ba5112fee70303ebf9dfbaffected · git
    • 5.8.3 and later · before 5.9affected · semver
    • before 5.9not affected · semver
    • 5.10.210 and later · up to and including 5.10.*not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.82-16.1.82-1
Debian:13linuxbefore 6.7.7-16.7.7-1

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-2024-26725Apr 3, 2024 · dpll: fix possible deadlock during netlink dump operation
    22Monitor
  • ← EarlierCVE-2024-26726Apr 3, 2024 · btrfs: don't drop extent_map for free space inode on write error
    22Monitor
  • Later →CVE-2023-52640Apr 3, 2024 · fs/ntfs3: Fix oob in ntfs_listxattr
    28Monitor

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 Linux3f5d47eb163bceb1b9e613c9003bae5fefc0046fVendor (CNA)
Linux Linux5.9Vendor (CNA)
Linux Linux5a172344bfdabb46458e03708735d7b1a918c468Vendor (CNA)
Linux Linux66b317a2fc45b2ef66527ee3f8fa08fb5beab88dVendor (CNA)
Linux Linux833775656d447c545133a744a0ed1e189ce61430Vendor (CNA)
Linux Linuxe03ee2fe873eb68c1f9ba5112fee70303ebf9dfbVendor (CNA)
Linux Linuxe31546b0f34af21738c4ceac47d662c00ee6382fVendor (CNA)
debian:linux6.1.82-1 · 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.

EPSS, last 120 days

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 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.

  • CVE-2023-2156330 days apartA flaw was found in the networking subsystem of the Linux kernel within the handling of the RPL protocol.
    32Monitor
  • CVE-2023-526218 days apartbpf: Check rcu_read_lock_trace_held() before calling bpf map helpers
    31Monitor
  • CVE-2025-39803530 days apartscsi: ufs: core: Remove WARN_ON_ONCE() call from ufshcd_uic_cmd_compl()
    31Monitor
  • CVE-2024-267260 days apartbtrfs: don't drop extent_map for free space inode on write error
    22Monitor
  • CVE-2022-4863325 days apartdrm/gma500: Fix WARN_ON(lock->magic != lock) error
    22Monitor
  • CVE-2024-2694628 days apartkprobes/x86: Use copy_from_kernel_nofault() to read from unsafe address
    22Monitor

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.

All national notices →

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-617 · Reachable Assertion

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✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (6 more)

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

All records