| 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-2025-21810: driver core: class: Fix wild pointer dereferences in API class_dev_iter_next() |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| driver core: class: Fix wild pointer dereferences in API class_dev_iter_next() |
| |
| There are a potential wild pointer dereferences issue regarding APIs |
| class_dev_iter_(init|next|exit)(), as explained by below typical usage: |
| |
| // All members of @iter are wild pointers. |
| struct class_dev_iter iter; |
| |
| // class_dev_iter_init(@iter, @class, ...) checks parameter @class for |
| // potential class_to_subsys() error, and it returns void type and does |
| // not initialize its output parameter @iter, so caller can not detect |
| // the error and continues to invoke class_dev_iter_next(@iter) even if |
| // @iter still contains wild pointers. |
| class_dev_iter_init(&iter, ...); |
| |
| // Dereference these wild pointers in @iter here once suffer the error. |
| while (dev = class_dev_iter_next(&iter)) { ... }; |
| |
| // Also dereference these wild pointers here. |
| class_dev_iter_exit(&iter); |
| |
| Actually, all callers of these APIs have such usage pattern in kernel tree. |
| Fix by: |
| - Initialize output parameter @iter by memset() in class_dev_iter_init() |
| and give callers prompt by pr_crit() for the error. |
| - Check if @iter is valid in class_dev_iter_next(). |
| |
| The Linux kernel CVE team has assigned CVE-2025-21810 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 6.4 with commit 7b884b7f24b42fa25e92ed724ad82f137610afaf and fixed in 6.6.76 with commit f4b9bc823b0cfdebfed479c0e87d6939c7562e87 |
| Issue introduced in 6.4 with commit 7b884b7f24b42fa25e92ed724ad82f137610afaf and fixed in 6.12.13 with commit 1614e75d1a1b63db6421c7a4bf37004720c7376c |
| Issue introduced in 6.4 with commit 7b884b7f24b42fa25e92ed724ad82f137610afaf and fixed in 6.13.2 with commit 5c504e9767b947cf7d4e29b811c0c8b3c53242b7 |
| Issue introduced in 6.4 with commit 7b884b7f24b42fa25e92ed724ad82f137610afaf and fixed in 6.14 with commit e128f82f7006991c99a58114f70ef61e937b1ac1 |
| |
| 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-2025-21810 |
| 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/base/class.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/f4b9bc823b0cfdebfed479c0e87d6939c7562e87 |
| https://git.kernel.org/stable/c/1614e75d1a1b63db6421c7a4bf37004720c7376c |
| https://git.kernel.org/stable/c/5c504e9767b947cf7d4e29b811c0c8b3c53242b7 |
| https://git.kernel.org/stable/c/e128f82f7006991c99a58114f70ef61e937b1ac1 |
