| 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-2023-52629: sh: push-switch: Reorder cleanup operations to avoid use-after-free bug |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| sh: push-switch: Reorder cleanup operations to avoid use-after-free bug |
| |
| The original code puts flush_work() before timer_shutdown_sync() |
| in switch_drv_remove(). Although we use flush_work() to stop |
| the worker, it could be rescheduled in switch_timer(). As a result, |
| a use-after-free bug can occur. The details are shown below: |
| |
| (cpu 0) | (cpu 1) |
| switch_drv_remove() | |
| flush_work() | |
| ... | switch_timer // timer |
| | schedule_work(&psw->work) |
| timer_shutdown_sync() | |
| ... | switch_work_handler // worker |
| kfree(psw) // free | |
| | psw->state = 0 // use |
| |
| This patch puts timer_shutdown_sync() before flush_work() to |
| mitigate the bugs. As a result, the worker and timer will be |
| stopped safely before the deallocate operations. |
| |
| The Linux kernel CVE team has assigned CVE-2023-52629 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 2.6.20 with commit 9f5e8eee5cfe1328660c71812d87c2a67bda389f and fixed in 6.5.4 with commit 610dbd8ac271aa36080aac50b928d700ee3fe4de |
| Issue introduced in 2.6.20 with commit 9f5e8eee5cfe1328660c71812d87c2a67bda389f and fixed in 6.6 with commit 246f80a0b17f8f582b2c0996db02998239057c65 |
| |
| 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-2023-52629 |
| 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: |
| arch/sh/drivers/push-switch.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/610dbd8ac271aa36080aac50b928d700ee3fe4de |
| https://git.kernel.org/stable/c/246f80a0b17f8f582b2c0996db02998239057c65 |
