| 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-2025-21954: netmem: prevent TX of unreadable skbs |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| netmem: prevent TX of unreadable skbs |
| |
| Currently on stable trees we have support for netmem/devmem RX but not |
| TX. It is not safe to forward/redirect an RX unreadable netmem packet |
| into the device's TX path, as the device may call dma-mapping APIs on |
| dma addrs that should not be passed to it. |
| |
| Fix this by preventing the xmit of unreadable skbs. |
| |
| Tested by configuring tc redirect: |
| |
| sudo tc qdisc add dev eth1 ingress |
| sudo tc filter add dev eth1 ingress protocol ip prio 1 flower ip_proto \ |
| tcp src_ip 192.168.1.12 action mirred egress redirect dev eth1 |
| |
| Before, I see unreadable skbs in the driver's TX path passed to dma |
| mapping APIs. |
| |
| After, I don't see unreadable skbs in the driver's TX path passed to dma |
| mapping APIs. |
| |
| The Linux kernel CVE team has assigned CVE-2025-21954 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 6.12 with commit 65249feb6b3df9e17bab5911ee56fa7b0971e231 and fixed in 6.12.20 with commit 454825019d2f0c59e5174ece9e713f45ad80beff |
| Issue introduced in 6.12 with commit 65249feb6b3df9e17bab5911ee56fa7b0971e231 and fixed in 6.13.8 with commit 1c17c8ced25c5fbe424c7ad7ea11d33014a986b1 |
| Issue introduced in 6.12 with commit 65249feb6b3df9e17bab5911ee56fa7b0971e231 and fixed in 6.14 with commit f3600c867c99a2cc8038680ecf211089c50e7971 |
| |
| 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-2025-21954 |
| 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: |
| net/core/dev.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/454825019d2f0c59e5174ece9e713f45ad80beff |
| https://git.kernel.org/stable/c/1c17c8ced25c5fbe424c7ad7ea11d33014a986b1 |
| https://git.kernel.org/stable/c/f3600c867c99a2cc8038680ecf211089c50e7971 |
