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NVD / CVE Program· CNA Linux

CVE-2023-53727: net/sched: fq_pie: avoid stalls in fq_pie_timer()

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: 0.19% (FIRST EPSS).
  • Fixed version: Linux Linux 8c21ab1bae945686c602c5bfa4e3f3352c2452c5, 94d527c3759d76c29220758362f622954612bea7, 973a4c302d7f3804098ff9824d9f56926901f293.

Low priority for now. Upgrade to Linux Linux 8c21ab1bae945686c602c5bfa4e3f3352c2452c5, 94d527c3759d76c29220758362f622954612bea7, 973a4c302d7f3804098ff9824d9f56926901f293 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: net/sched: fq_pie: avoid stalls in fq_pie_timer() When setting a high number of flows (limit being 65536), fq_pie_timer() is currently using too much time as syzbot reported. Add logic to yield the cpu every 2048 flows (less than 150 usec on debug kernels). It should also help by not blocking qdisc fast paths for too long. Worst case (65536 flows) would need 31 jiffies for a complete scan. Relevant extract from syzbot report: rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 0-.... } 2663 jiffies s: 873 root: 0x1/. rcu: blocking rcu_node structures (internal RCU debug): Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 5177 Comm: syz-executor273 Not tainted 6.5.0-syzkaller-00453-g727dbda16b83 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023 RIP: 0010:check_kcov_mode kernel/kcov.c:173 [inline] RIP: 0010:write_comp_data+0x21/0x90 kernel/kcov.c:236 Code: 2e 0f 1f 84 00 00 00 00 00 65 8b 05 01 b2 7d 7e 49 89 f1 89 c6 49 89 d2 81 e6 00 01 00 00 49 89 f8 65 48 8b 14 25 80 b9 03 00 <a9> 00 01 ff 00 74 0e 85 f6 74 59 8b 82 04 16 00 00 85 c0 74 4f 8b RSP: 0018:ffffc90000007bb8 EFLAGS: 00000206 RAX: 0000000000000101 RBX: ffffc9000dc0d140 RCX: ffffffff885893b0 RDX: ffff88807c075940 RSI: 0000000000000100 RDI: 0000000000000001 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffffc9000dc0d178 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 0000555555d54380(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f6b442f6130 CR3: 000000006fe1c000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <NMI> </NMI> <IRQ> pie_calculate_probability+0x480/0x850 net/sched/sch_pie.c:415 fq_pie_timer+0x1da/0x4f0 net/sched/sch_fq_pie.c:387 call_timer_fn+0x1a0/0x580 kernel/time/timer.c:1700

—No exploit Fix available
Published
Oct 22, 2025
Updated
Oct 28, 2026
EPSS
0.1% · 9th 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 · 0.1%

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  • 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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Noroxi analysis

What does it mean in your environment?

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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

    • 5.6affected
    • ec97ecf1ebe485a17cd8395a5f35e6b80b57665a and later · before 94d527c3759d76c29220758362f622954612bea7affected · git
    • ec97ecf1ebe485a17cd8395a5f35e6b80b57665a and later · before 973a4c302d7f3804098ff9824d9f56926901f293affected · git
    • ec97ecf1ebe485a17cd8395a5f35e6b80b57665a and later · before f39b49077abec4c9c3a4c2966532004851c51006affected · git
    • ec97ecf1ebe485a17cd8395a5f35e6b80b57665a and later · before e093000e7d13569c9cb07d7500acd5142c3c43cbaffected · git
    • ec97ecf1ebe485a17cd8395a5f35e6b80b57665a and later · before 8c21ab1bae945686c602c5bfa4e3f3352c2452c5affected · git
    • before 5.6not affected · semver
    • 5.10.195 and later · up to and including 5.10.*not affected · semver
    • 5.15.132 and later · up to and including 5.15.*not affected · semver
    • 6.1.54 and later · up to and including 6.1.*not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.55-16.1.55-1
Debian:13linuxbefore 6.5.6-16.5.6-1

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-2023-53725Oct 22, 2025 · clocksource/drivers/cadence-ttc: Fix memory leak in ttc_timer_probe
    0Monitor
  • ← EarlierCVE-2023-53726Oct 22, 2025 · arm64: csum: Fix OoB access in IP checksum code for negative lengths
    28Monitor
  • Later →CVE-2023-53729Oct 22, 2025 · soc: qcom: qmi_encdec: Restrict string length in decode
    31Monitor

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 Linux8c21ab1bae945686c602c5bfa4e3f3352c2452c5Vendor (CNA)
Linux Linux94d527c3759d76c29220758362f622954612bea7Vendor (CNA)
Linux Linux973a4c302d7f3804098ff9824d9f56926901f293Vendor (CNA)
Linux Linuxe093000e7d13569c9cb07d7500acd5142c3c43cbVendor (CNA)
Linux Linuxf39b49077abec4c9c3a4c2966532004851c51006Vendor (CNA)
debian:linux6.1.55-1 · 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.

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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 (4 more)

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

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