Updated: 2025-03-13 20:46:46.302876
Description:
In the Linux kernel, the following vulnerability has been resolved: tty: xilinx_uartps: split sysrq handling lockdep detects the following circular locking dependency: CPU 0 CPU 1 ========================== ============================ cdns_uart_isr() printk() uart_port_lock(port) console_lock() cdns_uart_console_write() if (!port->sysrq) uart_port_lock(port) uart_handle_break() port->sysrq = ... uart_handle_sysrq_char() printk() console_lock() The fixed commit attempts to avoid this situation by only taking the port lock in cdns_uart_console_write if port->sysrq unset. However, if (as shown above) cdns_uart_console_write runs before port->sysrq is set, then it will try to take the port lock anyway. This may result in a deadlock. Fix this by splitting sysrq handling into two parts. We use the prepare helper under the port lock and defer handling until we release the lock.
| Links | NIST | CIRCL | RHEL | Ubuntu |
| Severity | Score | |
|---|---|---|
| CVSS Version 2.x | 0 | |
| CVSS Version 3.x | MEDIUM | 5.5 |
| OS name | Project name | Version | Score | Severity | Status | Errata | Last updated | Statement |
|---|---|---|---|---|---|---|---|---|
| AlmaLinux 9.2 ESU | kernel | 5.14.0 | 5.5 | MEDIUM | Ignored | 2025-03-11 00:54:54 | ||
| AlmaLinux 9.6 ESU | kernel | 5.14.0 | 5.5 | MEDIUM | Ignored | 2025-07-05 02:18:09 | ||
| CentOS 8.4 ELS | kernel | 4.18.0 | 5.5 | MEDIUM | Ignored | 2025-03-11 00:54:52 | ||
| CentOS 8.5 ELS | kernel | 4.18.0 | 5.5 | MEDIUM | Ignored | 2025-03-11 00:54:53 | ||
| CentOS Stream 8 ELS | kernel | 4.18.0 | 5.5 | MEDIUM | Ignored | 2025-03-11 00:54:51 | ||
| Ubuntu 16.04 ELS | linux-hwe | 4.15.0 | 5.5 | MEDIUM | Ignored | 2025-03-11 02:53:13 | ||
| Ubuntu 18.04 ELS | linux | 4.15.0 | 5.5 | MEDIUM | Ignored | 2025-03-10 22:54:55 | ||
| Ubuntu 20.04 ELS | linux | 5.4.0 | 5.5 | MEDIUM | Ignored | 2025-06-24 00:42:01 |