| 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-2022-48867: dmaengine: idxd: Prevent use after free on completion memory |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| dmaengine: idxd: Prevent use after free on completion memory |
| |
| On driver unload any pending descriptors are flushed at the |
| time the interrupt is freed: |
| idxd_dmaengine_drv_remove() -> |
| drv_disable_wq() -> |
| idxd_wq_free_irq() -> |
| idxd_flush_pending_descs(). |
| |
| If there are any descriptors present that need to be flushed this |
| flow triggers a "not present" page fault as below: |
| |
| BUG: unable to handle page fault for address: ff391c97c70c9040 |
| #PF: supervisor read access in kernel mode |
| #PF: error_code(0x0000) - not-present page |
| |
| The address that triggers the fault is the address of the |
| descriptor that was freed moments earlier via: |
| drv_disable_wq()->idxd_wq_free_resources() |
| |
| Fix the use after free by freeing the descriptors after any possible |
| usage. This is done after idxd_wq_reset() to ensure that the memory |
| remains accessible during possible completion writes by the device. |
| |
| The Linux kernel CVE team has assigned CVE-2022-48867 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 5.19 with commit 63c14ae6c161dec8ff3be49277edc75a769e054a and fixed in 6.1.8 with commit b9e8e3fcfec625fc1c2f68f684448aeeb882625b |
| Issue introduced in 5.19 with commit 63c14ae6c161dec8ff3be49277edc75a769e054a and fixed in 6.2 with commit 1beeec45f9ac31eba52478379f70a5fa9c2ad005 |
| |
| 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-2022-48867 |
| 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/dma/idxd/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/b9e8e3fcfec625fc1c2f68f684448aeeb882625b |
| https://git.kernel.org/stable/c/1beeec45f9ac31eba52478379f70a5fa9c2ad005 |
