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.

https://git.kernel.org/stable/c/10014eb7eee351f7b587f8ac85830f0c9343cb9a

https://git.kernel.org/stable/c/14143ec10d69f42806b5d7b046f0fd1b835831ae

https://git.kernel.org/stable/c/9c92b42207978559e32903c3098aaf5c5b5788b2

https://git.kernel.org/stable/c/9fd48937046efc9abb89379d63ee9cc5c661d711

https://git.kernel.org/stable/c/a3bb136bff5e6a5e48cdd813246c9c4686feaaa9

https://git.kernel.org/stable/c/a9c22e0f93ba18322a6623ecdda2f0cd858ca350

https://git.kernel.org/stable/c/ee9eb72be95490602c493db050c73d925c3a4d74

https://git.kernel.org/stable/c/f4c3e63fa8639aedf96fb200d9939945a9eed51e

[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","programFiles":["drivers/tty/serial/samsung_tty.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","versions":[{"version":"b497549a035c2a81b71c7a27f2b00c8a16c09423","lessThan":"ee9eb72be95490602c493db050c73d925c3a4d74","versionType":"git","status":"affected"},{"version":"b497549a035c2a81b71c7a27f2b00c8a16c09423","lessThan":"10014eb7eee351f7b587f8ac85830f0c9343cb9a","versionType":"git","status":"affected"},{"version":"b497549a035c2a81b71c7a27f2b00c8a16c09423","lessThan":"f4c3e63fa8639aedf96fb200d9939945a9eed51e","versionType":"git","status":"affected"},{"version":"b497549a035c2a81b71c7a27f2b00c8a16c09423","lessThan":"a9c22e0f93ba18322a6623ecdda2f0cd858ca350","versionType":"git","status":"affected"},{"version":"b497549a035c2a81b71c7a27f2b00c8a16c09423","lessThan":"14143ec10d69f42806b5d7b046f0fd1b835831ae","versionType":"git","status":"affected"},{"version":"b497549a035c2a81b71c7a27f2b00c8a16c09423","lessThan":"9fd48937046efc9abb89379d63ee9cc5c661d711","versionType":"git","status":"affected"},{"version":"b497549a035c2a81b71c7a27f2b00c8a16c09423","lessThan":"9c92b42207978559e32903c3098aaf5c5b5788b2","versionType":"git","status":"affected"},{"version":"b497549a035c2a81b71c7a27f2b00c8a16c09423","lessThan":"a3bb136bff5e6a5e48cdd813246c9c4686feaaa9","versionType":"git","status":"affected"}]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","programFiles":["drivers/tty/serial/samsung_tty.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","versions":[{"version":"2.6.27","status":"affected"},{"version":"0","lessThan":"2.6.27","versionType":"semver","status":"unaffected"},{"version":"5.10.259","lessThanOrEqual":"5.10.*","versionType":"semver","status":"unaffected"},{"version":"5.15.210","lessThanOrEqual":"5.15.*","versionType":"semver","status":"unaffected"},{"version":"6.1.176","lessThanOrEqual":"6.1.*","versionType":"semver","status":"unaffected"},{"version":"6.6.143","lessThanOrEqual":"6.6.*","versionType":"semver","status":"unaffected"},{"version":"6.12.93","lessThanOrEqual":"6.12.*","versionType":"semver","status":"unaffected"},{"version":"6.18.35","lessThanOrEqual":"6.18.*","versionType":"semver","status":"unaffected"},{"version":"7.0.12","lessThanOrEqual":"7.0.*","versionType":"semver","status":"unaffected"},{"version":"7.1","lessThanOrEqual":"*","versionType":"original_commit_for_fix","status":"unaffected"}]}]