Description
In the Linux kernel, the following vulnerability has been resolved: serial: 8250: fix panic due to PSLVERR When the PSLVERR_RESP_EN parameter is set to 1, the device generates an error response if an attempt is made to read an empty RBR (Receive Buffer Register) while the FIFO is enabled. In serial8250_do_startup(), calling serial_port_out(port, UART_LCR, UART_LCR_WLEN8) triggers dw8250_check_lcr(), which invokes dw8250_force_idle() and serial8250_clear_and_reinit_fifos(). The latter function enables the FIFO via serial_out(p, UART_FCR, p->fcr). Execution proceeds to the serial_port_in(port, UART_RX). This satisfies the PSLVERR trigger condition. When another CPU (e.g., using printk()) is accessing the UART (UART is busy), the current CPU fails the check (value & ~UART_LCR_SPAR) == (lcr & ~UART_LCR_SPAR) in dw8250_check_lcr(), causing it to enter dw8250_force_idle(). Put serial_port_out(port, UART_LCR, UART_LCR_WLEN8) under the port->lock to fix this issue. Panic backtrace: [ 0.442336] Oops - unknown exception [#1] [ 0.442343] epc : dw8250_serial_in32+0x1e/0x4a [ 0.442351] ra : serial8250_do_startup+0x2c8/0x88e ... [ 0.442416] console_on_rootfs+0x26/0x70
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Linux Linux
Default version status: unaffected
c49436b657d0a56a6ad90d14a7c3041add7cf64d to < 0b882f00655afefbc7729c6b5aec86f7a5473a3daffectedc49436b657d0a56a6ad90d14a7c3041add7cf64d to < b8ca8e3f75ede308b4d49a6ca5081460be01bdb5affectedc49436b657d0a56a6ad90d14a7c3041add7cf64d to < 68c4613e89f000e8198f9ace643082c697921c9faffectedc49436b657d0a56a6ad90d14a7c3041add7cf64d to < c826943abf473a3f7260fbadfad65e44db475460affectedc49436b657d0a56a6ad90d14a7c3041add7cf64d to < cb7b3633ed749db8e56f475f43c960652cbd6882affectedc49436b657d0a56a6ad90d14a7c3041add7cf64d to < 8e2739478c164147d0774802008528d9e03fb802affectedc49436b657d0a56a6ad90d14a7c3041add7cf64d to < 38c0ea484dedb58cb3a4391229933e16be0d1031affectedc49436b657d0a56a6ad90d14a7c3041add7cf64d to < 7f8fdd4dbffc05982b96caf586f77a014b2a9353affected6d5e79331417886196cb3a733bdb6645ba85bc42affected2401577586898b3590db80f8b97a26f81f0f6d4eaffected3.10.48 to < 3.11affected3.12.24 to < 3.13affected
Linux Linux
Default version status: affected
3.13affected0 to < 3.13unaffected5.4.297 to ≤ 5.4.*unaffected5.10.241 to ≤ 5.10.*unaffected5.15.190 to ≤ 5.15.*unaffected6.1.149 to ≤ 6.1.*unaffected6.6.103 to ≤ 6.6.*unaffected6.12.44 to ≤ 6.12.*unaffected6.16.4 to ≤ 6.16.*unaffected6.17 to ≤ *unaffected
References
- https://git.kernel.org/stable/c/0b882f00655afefbc7729c6b5aec86f7a5473a3d ↗
- https://git.kernel.org/stable/c/b8ca8e3f75ede308b4d49a6ca5081460be01bdb5 ↗
- https://git.kernel.org/stable/c/68c4613e89f000e8198f9ace643082c697921c9f ↗
- https://git.kernel.org/stable/c/c826943abf473a3f7260fbadfad65e44db475460 ↗
- https://git.kernel.org/stable/c/cb7b3633ed749db8e56f475f43c960652cbd6882 ↗
- https://git.kernel.org/stable/c/8e2739478c164147d0774802008528d9e03fb802 ↗
- https://git.kernel.org/stable/c/38c0ea484dedb58cb3a4391229933e16be0d1031 ↗
- https://git.kernel.org/stable/c/7f8fdd4dbffc05982b96caf586f77a014b2a9353 ↗
- https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html ↗
- https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html ↗
- https://cert-portal.siemens.com/productcert/html/ssa-082556.html ↗
- https://cert-portal.siemens.com/productcert/html/ssa-032379.html ↗