| 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-2022-48961: net: mdio: fix unbalanced fwnode reference count in mdio_device_release() |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| net: mdio: fix unbalanced fwnode reference count in mdio_device_release() |
| |
| There is warning report about of_node refcount leak |
| while probing mdio device: |
| |
| OF: ERROR: memory leak, expected refcount 1 instead of 2, |
| of_node_get()/of_node_put() unbalanced - destroy cset entry: |
| attach overlay node /spi/soc@0/mdio@710700c0/ethernet@4 |
| |
| In of_mdiobus_register_device(), we increase fwnode refcount |
| by fwnode_handle_get() before associating the of_node with |
| mdio device, but it has never been decreased in normal path. |
| Since that, in mdio_device_release(), it needs to call |
| fwnode_handle_put() in addition instead of calling kfree() |
| directly. |
| |
| After above, just calling mdio_device_free() in the error handle |
| path of of_mdiobus_register_device() is enough to keep the |
| refcount balanced. |
| |
| The Linux kernel CVE team has assigned CVE-2022-48961 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 4.5 with commit a9049e0c513c4521dbfaa302af8ed08b3366b41f and fixed in 5.15.83 with commit 16854177745a5648f8ec322353b432e18460f43a |
| Issue introduced in 4.5 with commit a9049e0c513c4521dbfaa302af8ed08b3366b41f and fixed in 6.0.13 with commit a5c6de1a6656b8cc6bce7cb3d9874dd7df4968c3 |
| Issue introduced in 4.5 with commit a9049e0c513c4521dbfaa302af8ed08b3366b41f and fixed in 6.1 with commit cb37617687f2bfa5b675df7779f869147c9002bd |
| |
| 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-2022-48961 |
| 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/net/mdio/of_mdio.c |
| drivers/net/phy/mdio_device.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/16854177745a5648f8ec322353b432e18460f43a |
| https://git.kernel.org/stable/c/a5c6de1a6656b8cc6bce7cb3d9874dd7df4968c3 |
| https://git.kernel.org/stable/c/cb37617687f2bfa5b675df7779f869147c9002bd |
