| 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-2024-56760: PCI/MSI: Handle lack of irqdomain gracefully |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| PCI/MSI: Handle lack of irqdomain gracefully |
| |
| Alexandre observed a warning emitted from pci_msi_setup_msi_irqs() on a |
| RISCV platform which does not provide PCI/MSI support: |
| |
| WARNING: CPU: 1 PID: 1 at drivers/pci/msi/msi.h:121 pci_msi_setup_msi_irqs+0x2c/0x32 |
| __pci_enable_msix_range+0x30c/0x596 |
| pci_msi_setup_msi_irqs+0x2c/0x32 |
| pci_alloc_irq_vectors_affinity+0xb8/0xe2 |
| |
| RISCV uses hierarchical interrupt domains and correctly does not implement |
| the legacy fallback. The warning triggers from the legacy fallback stub. |
| |
| That warning is bogus as the PCI/MSI layer knows whether a PCI/MSI parent |
| domain is associated with the device or not. There is a check for MSI-X, |
| which has a legacy assumption. But that legacy fallback assumption is only |
| valid when legacy support is enabled, but otherwise the check should simply |
| return -ENOTSUPP. |
| |
| Loongarch tripped over the same problem and blindly enabled legacy support |
| without implementing the legacy fallbacks. There are weak implementations |
| which return an error, so the problem was papered over. |
| |
| Correct pci_msi_domain_supports() to evaluate the legacy mode and add |
| the missing supported check into the MSI enable path to complete it. |
| |
| The Linux kernel CVE team has assigned CVE-2024-56760 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 6.2 with commit d2a463b297415ca6dd4d60bb1c867dd7c931587b and fixed in 6.6.69 with commit b1f7476e07b93d65a1a3643dcb4a7bed80d4328d |
| Issue introduced in 6.2 with commit d2a463b297415ca6dd4d60bb1c867dd7c931587b and fixed in 6.12.8 with commit aed157301c659a48f5564cc4568cf0e5c8831af0 |
| Issue introduced in 6.2 with commit d2a463b297415ca6dd4d60bb1c867dd7c931587b and fixed in 6.13 with commit a60b990798eb17433d0283788280422b1bd94b18 |
| |
| 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-2024-56760 |
| 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/pci/msi/irqdomain.c |
| drivers/pci/msi/msi.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/b1f7476e07b93d65a1a3643dcb4a7bed80d4328d |
| https://git.kernel.org/stable/c/aed157301c659a48f5564cc4568cf0e5c8831af0 |
| https://git.kernel.org/stable/c/a60b990798eb17433d0283788280422b1bd94b18 |
