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NVD / CVE Program· CNA Linux

CVE-2023-53783: blk-iocost: fix divide by 0 error in calc_lcoefs()

Noroxi assessment

Priority: Monitor (action score 0/100)

  • 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: 0.20% (FIRST EPSS).
  • Fixed version: Linux Linux 3538ade9d8c2ba41088e395de916f2599fadba8f, 6e291810fe83a384700eb24a1f714966391ed562, 984af1e66b4126cf145153661cc24c213e2ec231.

Low priority for now. Upgrade to Linux Linux 3538ade9d8c2ba41088e395de916f2599fadba8f, 6e291810fe83a384700eb24a1f714966391ed562, 984af1e66b4126cf145153661cc24c213e2ec231 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: blk-iocost: fix divide by 0 error in calc_lcoefs() echo max of u64 to cost.model can cause divide by 0 error. # echo 8:0 rbps=18446744073709551615 > /sys/fs/cgroup/io.cost.model divide error: 0000 [#1] PREEMPT SMP RIP: 0010:calc_lcoefs+0x4c/0xc0 Call Trace: <TASK> ioc_refresh_params+0x2b3/0x4f0 ioc_cost_model_write+0x3cb/0x4c0 ? _copy_from_iter+0x6d/0x6c0 ? kernfs_fop_write_iter+0xfc/0x270 cgroup_file_write+0xa0/0x200 kernfs_fop_write_iter+0x17d/0x270 vfs_write+0x414/0x620 ksys_write+0x73/0x160 __x64_sys_write+0x1e/0x30 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x63/0xcd calc_lcoefs() uses the input value of cost.model in DIV_ROUND_UP_ULL, overflow would happen if bps plus IOC_PAGE_SIZE is greater than ULLONG_MAX, it can cause divide by 0 error. Fix the problem by setting basecost

—No exploit Fix available
Published
Dec 8, 2025
Updated
Jun 17, 2026
EPSS
0.2% · 10th percentile
CWE
—

Report tools

JSON

Action score

0

Monitor

Low priority for now.

CVSS
0 / 40 · —
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.2%

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  • A fix has been released

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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.

—

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

    • 5.4affected
    • 7caa47151ab2e644dd221f741ec7578d9532c9a3 and later · before 9e8bf9f95f7a299fa9ea45b678d001806ad5e12caffected · git
    • 7caa47151ab2e644dd221f741ec7578d9532c9a3 and later · before 6e291810fe83a384700eb24a1f714966391ed562affected · git
    • 7caa47151ab2e644dd221f741ec7578d9532c9a3 and later · before 3538ade9d8c2ba41088e395de916f2599fadba8faffected · git
    • 7caa47151ab2e644dd221f741ec7578d9532c9a3 and later · before bf8eb1fd6110871e6232e8e7efe399276ef7e6f6affected · git
    • 7caa47151ab2e644dd221f741ec7578d9532c9a3 and later · before b96d7b4a9745fbd0c8384608ceb1f50415e862faaffected · git
    • 7caa47151ab2e644dd221f741ec7578d9532c9a3 and later · before 984af1e66b4126cf145153661cc24c213e2ec231affected · git
    • before 5.4not affected · semver
    • 5.4.235 and later · up to and including 5.4.*not affected · semver
    • 5.10.173 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 6.1.20-16.1.20-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation
    40Plan
  • CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment
    40Plan
  • CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()
    40Plan

Published before and after this one in the same product

  • ← EarlierCVE-2023-53780Dec 8, 2025 · drm/amd/display: fix FCLK pstate change underflow
    0Monitor
  • ← EarlierCVE-2023-53782Dec 8, 2025 · dccp: Fix out of bounds access in DCCP error handler
    0Monitor
  • Later →CVE-2023-53784Dec 8, 2025 · drm: bridge: dw_hdmi: fix connector access for scdc
    0Monitor

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 Linux3538ade9d8c2ba41088e395de916f2599fadba8fVendor (CNA)
Linux Linux6e291810fe83a384700eb24a1f714966391ed562Vendor (CNA)
Linux Linux984af1e66b4126cf145153661cc24c213e2ec231Vendor (CNA)
Linux Linux9e8bf9f95f7a299fa9ea45b678d001806ad5e12cVendor (CNA)
Linux Linuxb96d7b4a9745fbd0c8384608ceb1f50415e862faVendor (CNA)
Linux Linuxbf8eb1fd6110871e6232e8e7efe399276ef7e6f6Vendor (CNA)
debian:linux6.1.20-1 · 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

No CVSS vector for this record, so attack conditions can't be derived.

Weakness class (CWE)

—

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.

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