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[34.82.187.25]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-2e2e5c1b3d7sm6751925ad.70.2026.09.30.05.59.02 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 30 Sep 2026 05:59:03 -0700 (PDT) From: Hui Peng To: Greg Kroah-Hartman , Jiri Slaby , John Ogness , =?UTF-8?q?Ilpo=20J=C3=A4rvinen?= Cc: Andy Shevchenko , linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org, Hui Peng Subject: [PATCH v7 0/2] serial: core: fix baud rate fallback loop and baud_base overflow Date: Wed, 30 Sep 2026 12:58:59 +0000 Message-ID: <20260930125901.778868-1-benquike@gmail.com> X-Mailer: git-send-email 2.56.0.rc1.315.gc6ed9934b7-goog Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit This series addresses two issues in serial core: 1. Division-by-zero WARN/Oops during baud rate fallback in uart_get_baud_rate(). 2. 32-bit unsigned overflow in uart_set_info() when multiplying new_info->baud_base by 16. Note on v6 1/3: Patch 1/3 from v6 ("serial: 8250: fix deadlock in serial8250_register_ports") has been dropped. The hash_mutex race condition was originally found and reproduced on Linux 6.18.14 (where guard(mutex)(&hash_mutex) was dropped inside serial_get_or_create_irq_info() before serial_link_irq_chain() linked the port). We did not realize that it was already fixed in mainline by commit b339809edda1 ("serial: 8250: use guard()s"), which refactored to serial_get_or_create_irq_info_locked() with guard(mutex)(&hash_mutex) moved into serial_link_irq_chain(). Apologies for the noise in v6 1/3. All remaining patches are ported to the latest tip of mainline (551c722f4080) and dynamically verified in QEMU KVM with CONFIG_KASAN=y. Changes in v7: - Dropped patch 1/3 (already resolved in mainline). - Clarified in cover letter that 1/3 was found and reproduced on 6.18.14 and we did not realize it was already fixed in mainline. - Retained patch 1/2 and patch 2/2 using check_mul_overflow() as requested by Jiri Slaby. Hui Peng (2): serial: core: fix baud rate fallback in uart_get_baud_rate() serial: core: reject baud_base values that overflow port->uartclk in uart_set_info() drivers/tty/serial/serial_core.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) -- 2.47.3