| 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-2024-35818: LoongArch: Define the __io_aw() hook as mmiowb() |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| LoongArch: Define the __io_aw() hook as mmiowb() |
| |
| Commit fb24ea52f78e0d595852e ("drivers: Remove explicit invocations of |
| mmiowb()") remove all mmiowb() in drivers, but it says: |
| |
| "NOTE: mmiowb() has only ever guaranteed ordering in conjunction with |
| spin_unlock(). However, pairing each mmiowb() removal in this patch with |
| the corresponding call to spin_unlock() is not at all trivial, so there |
| is a small chance that this change may regress any drivers incorrectly |
| relying on mmiowb() to order MMIO writes between CPUs using lock-free |
| synchronisation." |
| |
| The mmio in radeon_ring_commit() is protected by a mutex rather than a |
| spinlock, but in the mutex fastpath it behaves similar to spinlock. We |
| can add mmiowb() calls in the radeon driver but the maintainer says he |
| doesn't like such a workaround, and radeon is not the only example of |
| mutex protected mmio. |
| |
| So we should extend the mmiowb tracking system from spinlock to mutex, |
| and maybe other locking primitives. This is not easy and error prone, so |
| we solve it in the architectural code, by simply defining the __io_aw() |
| hook as mmiowb(). And we no longer need to override queued_spin_unlock() |
| so use the generic definition. |
| |
| Without this, we get such an error when run 'glxgears' on weak ordering |
| architectures such as LoongArch: |
| |
| radeon 0000:04:00.0: ring 0 stalled for more than 10324msec |
| radeon 0000:04:00.0: ring 3 stalled for more than 10240msec |
| radeon 0000:04:00.0: GPU lockup (current fence id 0x000000000001f412 last fence id 0x000000000001f414 on ring 3) |
| radeon 0000:04:00.0: GPU lockup (current fence id 0x000000000000f940 last fence id 0x000000000000f941 on ring 0) |
| radeon 0000:04:00.0: scheduling IB failed (-35). |
| [drm:radeon_gem_va_ioctl [radeon]] *ERROR* Couldn't update BO_VA (-35) |
| radeon 0000:04:00.0: scheduling IB failed (-35). |
| [drm:radeon_gem_va_ioctl [radeon]] *ERROR* Couldn't update BO_VA (-35) |
| radeon 0000:04:00.0: scheduling IB failed (-35). |
| [drm:radeon_gem_va_ioctl [radeon]] *ERROR* Couldn't update BO_VA (-35) |
| radeon 0000:04:00.0: scheduling IB failed (-35). |
| [drm:radeon_gem_va_ioctl [radeon]] *ERROR* Couldn't update BO_VA (-35) |
| radeon 0000:04:00.0: scheduling IB failed (-35). |
| [drm:radeon_gem_va_ioctl [radeon]] *ERROR* Couldn't update BO_VA (-35) |
| radeon 0000:04:00.0: scheduling IB failed (-35). |
| [drm:radeon_gem_va_ioctl [radeon]] *ERROR* Couldn't update BO_VA (-35) |
| radeon 0000:04:00.0: scheduling IB failed (-35). |
| [drm:radeon_gem_va_ioctl [radeon]] *ERROR* Couldn't update BO_VA (-35) |
| |
| The Linux kernel CVE team has assigned CVE-2024-35818 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 5.19 with commit fa96b57c149061f71a70bd6582d995f6424fbbf4 and fixed in 6.1.84 with commit 97cd43ba824aec764f5ea2790d0c0a318f885167 |
| Issue introduced in 5.19 with commit fa96b57c149061f71a70bd6582d995f6424fbbf4 and fixed in 6.6.24 with commit d7d7c6cdea875be3b241d7d39873bb431db7154d |
| Issue introduced in 5.19 with commit fa96b57c149061f71a70bd6582d995f6424fbbf4 and fixed in 6.7.12 with commit 0b61a7dc6712b78799b3949997e8a5e94db5c4b0 |
| Issue introduced in 5.19 with commit fa96b57c149061f71a70bd6582d995f6424fbbf4 and fixed in 6.8.3 with commit 9adec248bba33b1503252caf8e59d81febfc5ceb |
| Issue introduced in 5.19 with commit fa96b57c149061f71a70bd6582d995f6424fbbf4 and fixed in 6.9 with commit 9c68ece8b2a5c5ff9b2fcaea923dd73efeb174cd |
| |
| 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-2024-35818 |
| 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: |
| arch/loongarch/include/asm/Kbuild |
| arch/loongarch/include/asm/io.h |
| arch/loongarch/include/asm/qspinlock.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/97cd43ba824aec764f5ea2790d0c0a318f885167 |
| https://git.kernel.org/stable/c/d7d7c6cdea875be3b241d7d39873bb431db7154d |
| https://git.kernel.org/stable/c/0b61a7dc6712b78799b3949997e8a5e94db5c4b0 |
| https://git.kernel.org/stable/c/9adec248bba33b1503252caf8e59d81febfc5ceb |
| https://git.kernel.org/stable/c/9c68ece8b2a5c5ff9b2fcaea923dd73efeb174cd |
