CVE-2026-43061: Linux kernel · serial: 8250: Fix TX deadlock when using DMA
Affects Linux kernelSource CVE Database V5
Not known to be exploited · fixed in f76d91271bcacbd759a2e4ee3ea61faa6a727ccf : update Linux kernel when convenient.
Data as of 6 Nov 2026, 16:18 UTC
Rated Medium by Threat Radar's AI analysis · No CVSS score from NVD or the CNA
Thin evidence
One scorer or none- CISA SSVC
- Exploitation
- No evidence of active exploitation and no public proof of concept
- Automatable
- Attackers cannot reliably automate steps 1–4 of the kill chain
- Technical impact
- Limited control over the software or limited information exposure
CISA SSVC assessment, 2026-11-06.
- Patch
- Available – fixed in f76d91271bcacbd759a2e4ee3ea61faa6a727ccf, d2719a0a9c3439abf67843a5504b7afccd9ded93, b5ad887339503103d0fbe9827b16ad287597c275 +12
Exploitation evidence
Disclosed: evidence found.
CVE published 5 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 6 Nov 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in– |
AI-suggested
A fix has been implemented and is available in Linux kernel versions 5.10.253, 5.15.203, 6.1.167, 6.6.130, 6.12.78, 6.14, and later. Users and administrators should upgrade to these fixed versions to resolve the deadlock issue. No additional mitigation steps are indicated.
Description
A vulnerability in the Linux kernel's serial 8250 driver caused a transmit (TX) deadlock when using DMA. The issue arises because the dmaengine_terminate_async function does not guarantee execution of the __dma_tx_complete callback, which clears the dma->tx_running flag. If the callback is not run, the flag remains set, preventing new TX DMA transactions from being scheduled. The fix ensures dma->tx_running is cleared immediately after terminating the DMA transaction while holding the UART port lock, preventing deadlock.
References
- git.kernel.org/stable/c/8190f9ab6ad90cb97652adbebd238b874a4ef70d (opens in a new tab)
- git.kernel.org/stable/c/79a19bd936bb35f56ef0ccab1b3b59ebce8c762d (opens in a new tab)
- git.kernel.org/stable/c/f76d91271bcacbd759a2e4ee3ea61faa6a727ccf (opens in a new tab)
- git.kernel.org/stable/c/d2719a0a9c3439abf67843a5504b7afccd9ded93 (opens in a new tab)
- git.kernel.org/stable/c/2a72403b985aea6b4aac3171830492f9a387f9e1 (opens in a new tab)
- git.kernel.org/stable/c/5f6b17562f03fc65c7d3474ef8f1959b19d1ca41 (opens in a new tab)
- git.kernel.org/stable/c/b5ad887339503103d0fbe9827b16ad287597c275 (opens in a new tab)
- git.kernel.org/stable/c/a424a34b8faddf97b5af41689087e7a230f79ba7 (opens in a new tab)