What happened
In the Linux kernel, the following vulnerability has been resolved: serial: 8250: fix possible ISR soft lockup There are rare cases in which the host gets stuck in the ISR because it is flooded with messages during the startup phase. The reason for the soft lockup in the ISR is the missing FIFO error IRQ (FIFOE) handling. Not handling it and reporting IRQ_HANDLED triggers the IRQ immediately again. Fix this by adding a check for the FIFOE status and clearing the FIFO if no data is ready (DR). This behavior was observed on an AM62L device which uses the OMAP 8250 driver. Fix it for all 8250 drivers, since the OMAP driver's special IRQ setup handling may trigger this behavior more frequently, but it is not ensured that other 8250 drivers aren't affected.
Affected versions
Linux: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 through before 2881b2e6da02daea1eb8254247ba8fd20c9d3348 (git); 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 through before 4295c58990b7a84e8349a2226db692e252825b60 (git); 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 through before 0c6bf45e5a345cc3b9ffbeaf9083ecac3c2293eb (git); 2.6.12 Fixed: See vendor advisory.
Why it matters
Review the vendor advisory and exposure of the affected product to determine operational impact.
Detection & mitigation
- Apply vendor-provided updates or mitigations.
- Review affected product exposure and access logs.
Public PoC references
No public PoC reference has passed the current publication threshold.