CVE-2026-23168
MediumIn the Linux kernel, the following vulnerability has been resolved: flex_proportions: make fprop_new_period() hardirq safe Bernd has reported a lockdep splat from flexible proportions code that is essentially complaining about the following race: <timer fires> run_timer_softirq - we are in softirq context call_timer_fn writeout_period fprop_new_period write_seqcount_begin(&p->sequence); <hardirq is raised> ... blk_mq_end_request() blk_update_request() ext4_end_bio() folio_end_writeback() __wb_writeout_add() __fprop_add_percpu_max() if (unlikely(max_frac < FPROP_FRAC_BASE)) { fprop_fraction_percpu() seq = read_seqcount_begin(&p->sequence); - sees odd sequence so loops indefinitely Note that a deadlock like this is only possible if the bdi has configured maximum fraction of writeout throughput which is very rare in general but frequent for example for FUSE bdis. To fix this problem we have to make sure write section of the sequence counter is irqsafe.
CVSS 3.1 score
5.5
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Affected versions
Linux kernel versions
6.0
and later are affected. Fixed in
6.1.162,
6.6.123,
6.12.69,
6.18.9,
6.19
and their respective stable series.
References
The following references provide additional information about CVE-2026-23168 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.
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PatchKernel patch commithttps://git.kernel.org/stable/c/0acc9ba7a1b5ba4d998c5753e709be904e179b75
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PatchKernel patch commithttps://git.kernel.org/stable/c/78ede9ebd679dadf480dce6f7b798e3603f88348
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PatchKernel patch commithttps://git.kernel.org/stable/c/884b2590ffcc7222cbbd6298051f4c243cc36f5d
Frequently asked questions
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What is CVE-2026-23168?
CVE-2026-23168 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 . It affects Linux kernel versions from 6.0 onward and has been patched in 6.1.162, 6.6.123, 6.12.69 and others. CVE-2026-23168 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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What is the CVSS score for CVE-2026-23168?
CVE-2026-23168 has a CVSS score of 5.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H. -
Is there a patch available for CVE-2026-23168?
Yes — CVE-2026-23168 has been patched. Fixed versions include 6.1.162, 6.6.123, 6.12.69 and others. If you are running Linux kernel 6.0 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2026-23168 actively exploited?
No — CVE-2026-23168 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.