| From bippy-5f407fcff5a0 Mon Sep 17 00:00:00 2001 |
| From: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| To: <linux-cve-announce@vger.kernel.org> |
| Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org> |
| Subject: CVE-2023-52456: serial: imx: fix tx statemachine deadlock |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| serial: imx: fix tx statemachine deadlock |
| |
| When using the serial port as RS485 port, the tx statemachine is used to |
| control the RTS pin to drive the RS485 transceiver TX_EN pin. When the |
| TTY port is closed in the middle of a transmission (for instance during |
| userland application crash), imx_uart_shutdown disables the interface |
| and disables the Transmission Complete interrupt. afer that, |
| imx_uart_stop_tx bails on an incomplete transmission, to be retriggered |
| by the TC interrupt. This interrupt is disabled and therefore the tx |
| statemachine never transitions out of SEND. The statemachine is in |
| deadlock now, and the TX_EN remains low, making the interface useless. |
| |
| imx_uart_stop_tx now checks for incomplete transmission AND whether TC |
| interrupts are enabled before bailing to be retriggered. This makes sure |
| the state machine handling is reached, and is properly set to |
| WAIT_AFTER_SEND. |
| |
| The Linux kernel CVE team has assigned CVE-2023-52456 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 5.9 with commit cb1a609236096c278ecbfb7be678a693a70283f1 and fixed in 5.10.209 with commit 6e04a9d30509fb53ba6df5d655ed61d607a7cfda |
| Issue introduced in 5.9 with commit cb1a609236096c278ecbfb7be678a693a70283f1 and fixed in 5.15.148 with commit ff168d4fdb0e1ba35fb413a749b3d6cce918ec19 |
| Issue introduced in 5.9 with commit cb1a609236096c278ecbfb7be678a693a70283f1 and fixed in 6.1.75 with commit 63ee7be01a3f7d28b1ea8b8d7944f12bb7b0ed06 |
| Issue introduced in 5.9 with commit cb1a609236096c278ecbfb7be678a693a70283f1 and fixed in 6.6.14 with commit 763cd68746317b5d746dc2649a3295c1efb41181 |
| Issue introduced in 5.9 with commit cb1a609236096c278ecbfb7be678a693a70283f1 and fixed in 6.7.2 with commit 9a662d06c22ddfa371958c2071dc350436be802b |
| Issue introduced in 5.9 with commit cb1a609236096c278ecbfb7be678a693a70283f1 and fixed in 6.8 with commit 78d60dae9a0c9f09aa3d6477c94047df2fe6f7b0 |
| |
| Please see https://www.kernel.org for a full list of currently supported |
| kernel versions by the kernel community. |
| |
| Unaffected versions might change over time as fixes are backported to |
| older supported kernel versions. The official CVE entry at |
| https://cve.org/CVERecord/?id=CVE-2023-52456 |
| will be updated if fixes are backported, please check that for the most |
| up to date information about this issue. |
| |
| |
| Affected files |
| ============== |
| |
| The file(s) affected by this issue are: |
| drivers/tty/serial/imx.c |
| |
| |
| Mitigation |
| ========== |
| |
| The Linux kernel CVE team recommends that you update to the latest |
| stable kernel version for this, and many other bugfixes. Individual |
| changes are never tested alone, but rather are part of a larger kernel |
| release. Cherry-picking individual commits is not recommended or |
| supported by the Linux kernel community at all. If however, updating to |
| the latest release is impossible, the individual changes to resolve this |
| issue can be found at these commits: |
| https://git.kernel.org/stable/c/6e04a9d30509fb53ba6df5d655ed61d607a7cfda |
| https://git.kernel.org/stable/c/ff168d4fdb0e1ba35fb413a749b3d6cce918ec19 |
| https://git.kernel.org/stable/c/63ee7be01a3f7d28b1ea8b8d7944f12bb7b0ed06 |
| https://git.kernel.org/stable/c/763cd68746317b5d746dc2649a3295c1efb41181 |
| https://git.kernel.org/stable/c/9a662d06c22ddfa371958c2071dc350436be802b |
| https://git.kernel.org/stable/c/78d60dae9a0c9f09aa3d6477c94047df2fe6f7b0 |
