| 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-2024-26721: drm/i915/dsc: Fix the macro that calculates DSCC_/DSCA_ PPS reg address |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| drm/i915/dsc: Fix the macro that calculates DSCC_/DSCA_ PPS reg address |
| |
| Commit bd077259d0a9 ("drm/i915/vdsc: Add function to read any PPS |
| register") defines a new macro to calculate the DSC PPS register |
| addresses with PPS number as an input. This macro correctly calculates |
| the addresses till PPS 11 since the addresses increment by 4. So in that |
| case the following macro works correctly to give correct register |
| address: |
| |
| _MMIO(_DSCA_PPS_0 + (pps) * 4) |
| |
| However after PPS 11, the register address for PPS 12 increments by 12 |
| because of RC Buffer memory allocation in between. Because of this |
| discontinuity in the address space, the macro calculates wrong addresses |
| for PPS 12 - 16 resulting into incorrect DSC PPS parameter value |
| read/writes causing DSC corruption. |
| |
| This fixes it by correcting this macro to add the offset of 12 for PPS |
| >=12. |
| |
| v3: Add correct paranthesis for pps argument (Jani Nikula) |
| |
| (cherry picked from commit 6074be620c31dc2ae11af96a1a5ea95580976fb5) |
| |
| The Linux kernel CVE team has assigned CVE-2024-26721 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 6.7 with commit bd077259d0a9c9bf453e7e9751bf41f1996e6585 and fixed in 6.7.6 with commit ff5999fb03f467e1e7159f0ddb199c787f7512b9 |
| Issue introduced in 6.7 with commit bd077259d0a9c9bf453e7e9751bf41f1996e6585 and fixed in 6.8 with commit 962ac2dce56bb3aad1f82a4bbe3ada57a020287c |
| |
| 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-2024-26721 |
| 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/gpu/drm/i915/display/intel_vdsc_regs.h |
| |
| |
| 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/ff5999fb03f467e1e7159f0ddb199c787f7512b9 |
| https://git.kernel.org/stable/c/962ac2dce56bb3aad1f82a4bbe3ada57a020287c |
