| 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-2023-52455: iommu: Don't reserve 0-length IOVA region |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| iommu: Don't reserve 0-length IOVA region |
| |
| When the bootloader/firmware doesn't setup the framebuffers, their |
| address and size are 0 in "iommu-addresses" property. If IOVA region is |
| reserved with 0 length, then it ends up corrupting the IOVA rbtree with |
| an entry which has pfn_hi < pfn_lo. |
| If we intend to use display driver in kernel without framebuffer then |
| it's causing the display IOMMU mappings to fail as entire valid IOVA |
| space is reserved when address and length are passed as 0. |
| An ideal solution would be firmware removing the "iommu-addresses" |
| property and corresponding "memory-region" if display is not present. |
| But the kernel should be able to handle this by checking for size of |
| IOVA region and skipping the IOVA reservation if size is 0. Also, add |
| a warning if firmware is requesting 0-length IOVA region reservation. |
| |
| The Linux kernel CVE team has assigned CVE-2023-52455 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 6.3 with commit a5bf3cfce8cb77d9d24613ab52d520896f83dd48 and fixed in 6.6.14 with commit 98b8a550da83cc392a14298c4b3eaaf0332ae6ad |
| Issue introduced in 6.3 with commit a5bf3cfce8cb77d9d24613ab52d520896f83dd48 and fixed in 6.7.2 with commit 5e23e283910c9f30248732ae0770bcb0c9438abf |
| Issue introduced in 6.3 with commit a5bf3cfce8cb77d9d24613ab52d520896f83dd48 and fixed in 6.8 with commit bb57f6705960bebeb832142ce9abf43220c3eab1 |
| |
| 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-2023-52455 |
| 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/iommu/of_iommu.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/98b8a550da83cc392a14298c4b3eaaf0332ae6ad |
| https://git.kernel.org/stable/c/5e23e283910c9f30248732ae0770bcb0c9438abf |
| https://git.kernel.org/stable/c/bb57f6705960bebeb832142ce9abf43220c3eab1 |
