| From bippy-1.2.0 Mon Sep 17 00:00:00 2001 |
| From: Greg Kroah-Hartman <gregkh@kernel.org> |
| To: <linux-cve-announce@vger.kernel.org> |
| Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org> |
| Subject: CVE-2025-37837: iommu/tegra241-cmdqv: Fix warnings due to dmam_free_coherent() |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| iommu/tegra241-cmdqv: Fix warnings due to dmam_free_coherent() |
| |
| Two WARNINGs are observed when SMMU driver rolls back upon failure: |
| arm-smmu-v3.9.auto: Failed to register iommu |
| arm-smmu-v3.9.auto: probe with driver arm-smmu-v3 failed with error -22 |
| ------------[ cut here ]------------ |
| WARNING: CPU: 5 PID: 1 at kernel/dma/mapping.c:74 dmam_free_coherent+0xc0/0xd8 |
| Call trace: |
| dmam_free_coherent+0xc0/0xd8 (P) |
| tegra241_vintf_free_lvcmdq+0x74/0x188 |
| tegra241_cmdqv_remove_vintf+0x60/0x148 |
| tegra241_cmdqv_remove+0x48/0xc8 |
| arm_smmu_impl_remove+0x28/0x60 |
| devm_action_release+0x1c/0x40 |
| ------------[ cut here ]------------ |
| 128 pages are still in use! |
| WARNING: CPU: 16 PID: 1 at mm/page_alloc.c:6902 free_contig_range+0x18c/0x1c8 |
| Call trace: |
| free_contig_range+0x18c/0x1c8 (P) |
| cma_release+0x154/0x2f0 |
| dma_free_contiguous+0x38/0xa0 |
| dma_direct_free+0x10c/0x248 |
| dma_free_attrs+0x100/0x290 |
| dmam_free_coherent+0x78/0xd8 |
| tegra241_vintf_free_lvcmdq+0x74/0x160 |
| tegra241_cmdqv_remove+0x98/0x198 |
| arm_smmu_impl_remove+0x28/0x60 |
| devm_action_release+0x1c/0x40 |
| |
| This is because the LVCMDQ queue memory are managed by devres, while that |
| dmam_free_coherent() is called in the context of devm_action_release(). |
| |
| Jason pointed out that "arm_smmu_impl_probe() has mis-ordered the devres |
| callbacks if ops->device_remove() is going to be manually freeing things |
| that probe allocated": |
| https://lore.kernel.org/linux-iommu/20250407174408.GB1722458@nvidia.com/ |
| |
| In fact, tegra241_cmdqv_init_structures() only allocates memory resources |
| which means any failure that it generates would be similar to -ENOMEM, so |
| there is no point in having that "falling back to standard SMMU" routine, |
| as the standard SMMU would likely fail to allocate memory too. |
| |
| Remove the unwind part in tegra241_cmdqv_init_structures(), and return a |
| proper error code to ask SMMU driver to call tegra241_cmdqv_remove() via |
| impl_ops->device_remove(). Then, drop tegra241_vintf_free_lvcmdq() since |
| devres will take care of that. |
| |
| The Linux kernel CVE team has assigned CVE-2025-37837 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 6.12 with commit 483e0bd8883a40fd3dd3193997a4014337698d72 and fixed in 6.12.24 with commit e5dd974d6e00704553308ef1a88659f8dcfb39d4 |
| Issue introduced in 6.12 with commit 483e0bd8883a40fd3dd3193997a4014337698d72 and fixed in 6.13.12 with commit 5584dbf393df509159813645a487b1ef76557722 |
| Issue introduced in 6.12 with commit 483e0bd8883a40fd3dd3193997a4014337698d72 and fixed in 6.14.3 with commit e38ed6908080047d8fa1763d1da86b584f9eb55b |
| Issue introduced in 6.12 with commit 483e0bd8883a40fd3dd3193997a4014337698d72 and fixed in 6.15 with commit 767e22001dfce64cc03b7def1562338591ab6031 |
| |
| 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-2025-37837 |
| 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/arm/arm-smmu-v3/tegra241-cmdqv.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/e5dd974d6e00704553308ef1a88659f8dcfb39d4 |
| https://git.kernel.org/stable/c/5584dbf393df509159813645a487b1ef76557722 |
| https://git.kernel.org/stable/c/e38ed6908080047d8fa1763d1da86b584f9eb55b |
| https://git.kernel.org/stable/c/767e22001dfce64cc03b7def1562338591ab6031 |
