| 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-2022-48985: net: mana: Fix race on per-CQ variable napi work_done |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| net: mana: Fix race on per-CQ variable napi work_done |
| |
| After calling napi_complete_done(), the NAPIF_STATE_SCHED bit may be |
| cleared, and another CPU can start napi thread and access per-CQ variable, |
| cq->work_done. If the other thread (for example, from busy_poll) sets |
| it to a value >= budget, this thread will continue to run when it should |
| stop, and cause memory corruption and panic. |
| |
| To fix this issue, save the per-CQ work_done variable in a local variable |
| before napi_complete_done(), so it won't be corrupted by a possible |
| concurrent thread after napi_complete_done(). |
| |
| Also, add a flag bit to advertise to the NIC firmware: the NAPI work_done |
| variable race is fixed, so the driver is able to reliably support features |
| like busy_poll. |
| |
| The Linux kernel CVE team has assigned CVE-2022-48985 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 5.15 with commit e1b5683ff62e7b328317aec08869495992053e9d and fixed in 5.15.83 with commit fe50a9bbeb1f042e756c5cfa7708112c944368de |
| Issue introduced in 5.15 with commit e1b5683ff62e7b328317aec08869495992053e9d and fixed in 6.0.13 with commit 6740d8572ccd1bca50d8a1ca2bedc333f50ed5f3 |
| Issue introduced in 5.15 with commit e1b5683ff62e7b328317aec08869495992053e9d and fixed in 6.1 with commit 18010ff776fa42340efc428b3ea6d19b3e7c7b21 |
| |
| 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-2022-48985 |
| 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/ethernet/microsoft/mana/gdma.h |
| drivers/net/ethernet/microsoft/mana/mana_en.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/fe50a9bbeb1f042e756c5cfa7708112c944368de |
| https://git.kernel.org/stable/c/6740d8572ccd1bca50d8a1ca2bedc333f50ed5f3 |
| https://git.kernel.org/stable/c/18010ff776fa42340efc428b3ea6d19b3e7c7b21 |
