CVE-2025-21820 - CERT CVE
ID CVE-2025-21820
Sažetak 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.
Reference
CVSS
Base: 5.5
Impact: 3.6
Exploitability:1.8
Pristup
VektorSloženostAutentikacija
LOCAL LOW LOW
Impact
PovjerljivostCjelovitostDostupnost
NONE NONE HIGH
CVSS vektor CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Zadnje važnije ažuriranje 13-03-2025 - 13:15
Objavljeno 27-02-2025 - 20:16