| 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-2021-46969: bus: mhi: core: Fix invalid error returning in mhi_queue |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| bus: mhi: core: Fix invalid error returning in mhi_queue |
| |
| mhi_queue returns an error when the doorbell is not accessible in |
| the current state. This can happen when the device is in non M0 |
| state, like M3, and needs to be waken-up prior ringing the DB. This |
| case is managed earlier by triggering an asynchronous M3 exit via |
| controller resume/suspend callbacks, that in turn will cause M0 |
| transition and DB update. |
| |
| So, since it's not an error but just delaying of doorbell update, there |
| is no reason to return an error. |
| |
| This also fixes a use after free error for skb case, indeed a caller |
| queuing skb will try to free the skb if the queueing fails, but in |
| that case queueing has been done. |
| |
| The Linux kernel CVE team has assigned CVE-2021-46969 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 5.12 with commit a8f75cb348fd52e7a5cf25991cdf9c89fb0cfd41 and fixed in 5.12.3 with commit a99b661c3187365f81026d89b1133a76cd2652b3 |
| Issue introduced in 5.12 with commit a8f75cb348fd52e7a5cf25991cdf9c89fb0cfd41 and fixed in 5.13 with commit 0ecc1c70dcd32c0f081b173a1a5d89952686f271 |
| |
| 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-2021-46969 |
| 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/bus/mhi/core/main.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/a99b661c3187365f81026d89b1133a76cd2652b3 |
| https://git.kernel.org/stable/c/0ecc1c70dcd32c0f081b173a1a5d89952686f271 |
