CVE-2026-64528: Linux kernel · tty: serial: samsung: Remove redundant port lock acquisition in rx helpers
Source GCVE Database
Not known to be exploited.
Data as of 26 Oct 2026, 17:16 UTC
Rated by Threat Radar · No CVSS score from NVD or the CNA
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 6% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Exploitation evidence
Disclosed: evidence found.
CVE published 25 Jul 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 26 Oct 2026.
What to do
AI-suggested
A fix has been applied to the Linux kernel to remove the redundant port lock acquisition in the Samsung serial driver's rx helper functions. Users should update to a kernel version that includes this fix. Since this is a kernel-level issue, applying the official kernel update or patch from the Linux kernel maintainers is the recommended remediation. Patch status is not explicitly confirmed in the provided data; users should verify with the vendor or kernel release notes for the exact fixed version.
Description
In the Linux kernel, the following vulnerability has been resolved: tty: serial: samsung: Remove redundant port lock acquisition in rx helpers Sashiko identified a deadlock when the console flow is engaged [1]. When console flow control is enabled (UPF_CONS_FLOW), s3c24xx_serial_stop_tx() calls s3c24xx_serial_rx_enable() and s3c24xx_serial_start_tx() calls s3c24xx_serial_rx_disable(). The serial core framework invokes the .stop_tx() and .start_tx() callbacks with the port->lock spinlock already held. Furthermore, all internal driver paths that invoke stop_tx (such as the DMA TX completion handler s3c24xx_serial_tx_dma_complete() or the PIO TX IRQ handler s3c24xx_serial_tx_irq()) also acquire port->lock prior to calling it. (Note that s3c24xx_serial_start_tx() is only invoked by the serial core). However, s3c24xx_serial_rx_enable() and s3c24xx_serial_rx_disable() unconditionally attempt to acquire port->lock again using uart_port_lock_irqsave(). Since spinlocks are not recursive, this causes a deadlock on the same CPU when console flow control is engaged. Remove the redundant lock acquisition from both rx helper functions.
References
- nvd.nist.gov/vuln/detail/CVE-2026-64528 (opens in a new tab)
- git.kernel.org/stable/c/10014eb7eee351f7b587f8ac85830f0c9343cb9a (opens in a new tab)
- git.kernel.org/stable/c/14143ec10d69f42806b5d7b046f0fd1b835831ae (opens in a new tab)
- git.kernel.org/stable/c/9c92b42207978559e32903c3098aaf5c5b5788b2 (opens in a new tab)
- git.kernel.org/stable/c/9fd48937046efc9abb89379d63ee9cc5c661d711 (opens in a new tab)
- git.kernel.org/stable/c/a3bb136bff5e6a5e48cdd813246c9c4686feaaa9 (opens in a new tab)
- git.kernel.org/stable/c/a9c22e0f93ba18322a6623ecdda2f0cd858ca350 (opens in a new tab)
- git.kernel.org/stable/c/ee9eb72be95490602c493db050c73d925c3a4d74 (opens in a new tab)
- git.kernel.org/stable/c/f4c3e63fa8639aedf96fb200d9939945a9eed51e (opens in a new tab)