| 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-2023-52872: tty: n_gsm: fix race condition in status line change on dead connections |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| tty: n_gsm: fix race condition in status line change on dead connections |
| |
| gsm_cleanup_mux() cleans up the gsm by closing all DLCIs, stopping all |
| timers, removing the virtual tty devices and clearing the data queues. |
| This procedure, however, may cause subsequent changes of the virtual modem |
| status lines of a DLCI. More data is being added the outgoing data queue |
| and the deleted kick timer is restarted to handle this. At this point many |
| resources have already been removed by the cleanup procedure. Thus, a |
| kernel panic occurs. |
| |
| Fix this by proving in gsm_modem_update() that the cleanup procedure has |
| not been started and the mux is still alive. |
| |
| Note that writing to a virtual tty is already protected by checks against |
| the DLCI specific connection state. |
| |
| The Linux kernel CVE team has assigned CVE-2023-52872 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 5.15.61 with commit dd37f657387853623f20c1b2482afbb9cd8ece33 and fixed in 5.15.138 with commit 81a4dd5e6c78f5d8952fa8c9d36565db1fe01444 |
| Issue introduced in 6.0 with commit c568f7086c6e771c77aad13d727c70ef70e07243 and fixed in 6.1.62 with commit df6cfab66ff2a44bd23ad5dd5309cb3421bb6593 |
| Issue introduced in 6.0 with commit c568f7086c6e771c77aad13d727c70ef70e07243 and fixed in 6.5.11 with commit 19d34b73234af542cc8a218cf398dee73cdb1890 |
| Issue introduced in 6.0 with commit c568f7086c6e771c77aad13d727c70ef70e07243 and fixed in 6.6.1 with commit ce4df90333c4fe65acb8b5089fdfe9b955ce976a |
| Issue introduced in 6.0 with commit c568f7086c6e771c77aad13d727c70ef70e07243 and fixed in 6.7 with commit 3a75b205de43365f80a33b98ec9289785da56243 |
| Issue introduced in 5.18.18 with commit d834aba5f30d9a6f98f4ca1eb07e501f1989331c |
| Issue introduced in 5.19.2 with commit 692e847a8e6607909c4a3f98ab16ccee7849bd11 |
| |
| 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-2023-52872 |
| 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/n_gsm.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/81a4dd5e6c78f5d8952fa8c9d36565db1fe01444 |
| https://git.kernel.org/stable/c/df6cfab66ff2a44bd23ad5dd5309cb3421bb6593 |
| https://git.kernel.org/stable/c/19d34b73234af542cc8a218cf398dee73cdb1890 |
| https://git.kernel.org/stable/c/ce4df90333c4fe65acb8b5089fdfe9b955ce976a |
| https://git.kernel.org/stable/c/3a75b205de43365f80a33b98ec9289785da56243 |
