| From bippy-7c5fe7eed585 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-2025-21915: cdx: Fix possible UAF error in driver_override_show() |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| cdx: Fix possible UAF error in driver_override_show() |
| |
| Fixed a possible UAF problem in driver_override_show() in drivers/cdx/cdx.c |
| |
| This function driver_override_show() is part of DEVICE_ATTR_RW, which |
| includes both driver_override_show() and driver_override_store(). |
| These functions can be executed concurrently in sysfs. |
| |
| The driver_override_store() function uses driver_set_override() to |
| update the driver_override value, and driver_set_override() internally |
| locks the device (device_lock(dev)). If driver_override_show() reads |
| cdx_dev->driver_override without locking, it could potentially access |
| a freed pointer if driver_override_store() frees the string |
| concurrently. This could lead to printing a kernel address, which is a |
| security risk since DEVICE_ATTR can be read by all users. |
| |
| Additionally, a similar pattern is used in drivers/amba/bus.c, as well |
| as many other bus drivers, where device_lock() is taken in the show |
| function, and it has been working without issues. |
| |
| This potential bug was detected by our experimental static analysis |
| tool, which analyzes locking APIs and paired functions to identify |
| data races and atomicity violations. |
| |
| The Linux kernel CVE team has assigned CVE-2025-21915 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 6.4 with commit 2959ab247061e67485d83b6af8feb3761ec08cb9 and fixed in 6.6.83 with commit d7b339bbc887bcfc1a5b620bfc70c6fbb8f733bf |
| Issue introduced in 6.4 with commit 2959ab247061e67485d83b6af8feb3761ec08cb9 and fixed in 6.12.19 with commit 8473135f89c0949436a22adb05b8cece2fb3da91 |
| Issue introduced in 6.4 with commit 2959ab247061e67485d83b6af8feb3761ec08cb9 and fixed in 6.13.7 with commit 0439d541aa8d3444ad41c39e39eb71acb57acde3 |
| Issue introduced in 6.4 with commit 2959ab247061e67485d83b6af8feb3761ec08cb9 and fixed in 6.14 with commit 91d44c1afc61a2fec37a9c7a3485368309391e0b |
| |
| 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-2025-21915 |
| 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/cdx/cdx.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/d7b339bbc887bcfc1a5b620bfc70c6fbb8f733bf |
| https://git.kernel.org/stable/c/8473135f89c0949436a22adb05b8cece2fb3da91 |
| https://git.kernel.org/stable/c/0439d541aa8d3444ad41c39e39eb71acb57acde3 |
| https://git.kernel.org/stable/c/91d44c1afc61a2fec37a9c7a3485368309391e0b |
