{"id":"CVE-2025-39724","summary":"serial: 8250: fix panic due to PSLVERR","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nserial: 8250: fix panic due to PSLVERR\n\nWhen the PSLVERR_RESP_EN parameter is set to 1, the device generates\nan error response if an attempt is made to read an empty RBR (Receive\nBuffer Register) while the FIFO is enabled.\n\nIn serial8250_do_startup(), calling serial_port_out(port, UART_LCR,\nUART_LCR_WLEN8) triggers dw8250_check_lcr(), which invokes\ndw8250_force_idle() and serial8250_clear_and_reinit_fifos(). The latter\nfunction enables the FIFO via serial_out(p, UART_FCR, p-\u003efcr).\nExecution proceeds to the serial_port_in(port, UART_RX).\nThis satisfies the PSLVERR trigger condition.\n\nWhen another CPU (e.g., using printk()) is accessing the UART (UART\nis busy), the current CPU fails the check (value & ~UART_LCR_SPAR) ==\n(lcr & ~UART_LCR_SPAR) in dw8250_check_lcr(), causing it to enter\ndw8250_force_idle().\n\nPut serial_port_out(port, UART_LCR, UART_LCR_WLEN8) under the port-\u003elock\nto fix this issue.\n\nPanic backtrace:\n[    0.442336] Oops - unknown exception [#1]\n[    0.442343] epc : dw8250_serial_in32+0x1e/0x4a\n[    0.442351]  ra : serial8250_do_startup+0x2c8/0x88e\n...\n[    0.442416] console_on_rootfs+0x26/0x70","modified":"2026-03-20T12:43:01.026623Z","published":"2025-09-05T17:21:32.005Z","related":["MGASA-2025-0234","MGASA-2025-0235","SUSE-SU-2025:03600-1","SUSE-SU-2025:03634-1","SUSE-SU-2025:20851-1","SUSE-SU-2025:20861-1","SUSE-SU-2025:20870-1","SUSE-SU-2025:20898-1","SUSE-SU-2025:21074-1","SUSE-SU-2025:21139-1","SUSE-SU-2025:21179-1","SUSE-SU-2025:3751-1","SUSE-SU-2025:4057-1","SUSE-SU-2025:4132-1","SUSE-SU-2025:4141-1","SUSE-SU-2025:4189-1","openSUSE-SU-2025:20081-1"],"database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/39xxx/CVE-2025-39724.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/0b882f00655afefbc7729c6b5aec86f7a5473a3d"},{"type":"WEB","url":"https://git.kernel.org/stable/c/38c0ea484dedb58cb3a4391229933e16be0d1031"},{"type":"WEB","url":"https://git.kernel.org/stable/c/68c4613e89f000e8198f9ace643082c697921c9f"},{"type":"WEB","url":"https://git.kernel.org/stable/c/7f8fdd4dbffc05982b96caf586f77a014b2a9353"},{"type":"WEB","url":"https://git.kernel.org/stable/c/8e2739478c164147d0774802008528d9e03fb802"},{"type":"WEB","url":"https://git.kernel.org/stable/c/b8ca8e3f75ede308b4d49a6ca5081460be01bdb5"},{"type":"WEB","url":"https://git.kernel.org/stable/c/c826943abf473a3f7260fbadfad65e44db475460"},{"type":"WEB","url":"https://git.kernel.org/stable/c/cb7b3633ed749db8e56f475f43c960652cbd6882"},{"type":"WEB","url":"https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html"},{"type":"WEB","url":"https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/39xxx/CVE-2025-39724.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-39724"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"c49436b657d0a56a6ad90d14a7c3041add7cf64d"},{"fixed":"0b882f00655afefbc7729c6b5aec86f7a5473a3d"},{"fixed":"b8ca8e3f75ede308b4d49a6ca5081460be01bdb5"},{"fixed":"68c4613e89f000e8198f9ace643082c697921c9f"},{"fixed":"c826943abf473a3f7260fbadfad65e44db475460"},{"fixed":"cb7b3633ed749db8e56f475f43c960652cbd6882"},{"fixed":"8e2739478c164147d0774802008528d9e03fb802"},{"fixed":"38c0ea484dedb58cb3a4391229933e16be0d1031"},{"fixed":"7f8fdd4dbffc05982b96caf586f77a014b2a9353"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"0"},{"last_affected":"6d5e79331417886196cb3a733bdb6645ba85bc42"},{"last_affected":"2401577586898b3590db80f8b97a26f81f0f6d4e"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2025-39724.json"}}],"schema_version":"1.7.5"}