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Fencer Vulns
no cvss —

CVE-2023-53783 json

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

published 2025-12-09 11 mo ago modified 2026-06-17 4 mo ago also EUVD-2023-60123

cvss
—
not scored
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 10%
public exploits
0
none known

Summary

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

Patch / fix

  • Linux Linux 5.4.235, 5.10.173, 5.15.99, 6.1.16, 6.2.3, 6.3
  • linux Debian 14, Debian 13, Debian 12 6.1.20-1

debian advisories DEBIAN-CVE-2023-53783

  • linux Ubuntu 20.04 LTS 5.4.0-152.169
  • linux Ubuntu 22.04 LTS 5.15.0-75.82
  • linux-aws Ubuntu 20.04 LTS 5.4.0-1104.112
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1038.43
  • linux-gcp Ubuntu 20.04 LTS 5.4.0-1107.116
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1036.44
  • linux-gke Ubuntu 22.04 LTS 5.15.0-1036.41
  • linux-ibm Ubuntu 20.04 LTS 5.4.0-1051.56

ubuntu advisories UBUNTU-CVE-2023-53783

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • kernel-64kb SLES 15 SP4-LTSS, SLE High Performance Computing 15 SP4-LTSS, SLE High Performance Computing 15 SP4-ESPOS 5.14.21-150400.24.194.1
  • kernel-syms SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE High Performance Computing 15 SP4-LTSS +1 more 5.14.21-150400.24.194.1
  • kernel-source SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE High Performance Computing 15 SP4-LTSS +1 more 5.14.21-150400.24.194.1
  • kernel-default SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE Micro 5.4 +5 more 5.14.21-150400.24.194.1
  • kernel-obs-build SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE High Performance Computing 15 SP4-LTSS +1 more 5.14.21-150400.24.194.1
  • kernel-default-base SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE Micro 5.4 +3 more 5.14.21-150400.24.194.1.150400.24.98.3
  • kernel-rt SLE Micro 5.4, SLE Micro 5.3 5.14.21-150400.15.142.1
  • kernel-source-rt SLE Micro 5.4, SLE Micro 5.3 5.14.21-150400.15.142.1

suse advisories SUSE-SU-2026:0617-1SUSE-SU-2026:0411-1SUSE-SU-2026:0317-1SUSE-SU-2026:0263-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2023-53783 updated cvss 5.5

kernel: blk-iocost: fix divide by 0 error in calc_lcoefs()

  • Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more
    affected: no fix available
  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 10 kernel
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

0.21% chance of exploitation in the next 30 days, higher than 10% of all scored CVEs (FIRST EPSS, 2026-11-08).

Affected products

  • Linux Linux

Classification

Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.