| 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-2024-26785: iommufd: Fix protection fault in iommufd_test_syz_conv_iova |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| iommufd: Fix protection fault in iommufd_test_syz_conv_iova |
| |
| Syzkaller reported the following bug: |
| |
| general protection fault, probably for non-canonical address 0xdffffc0000000038: 0000 [#1] SMP KASAN |
| KASAN: null-ptr-deref in range [0x00000000000001c0-0x00000000000001c7] |
| Call Trace: |
| lock_acquire |
| lock_acquire+0x1ce/0x4f0 |
| down_read+0x93/0x4a0 |
| iommufd_test_syz_conv_iova+0x56/0x1f0 |
| iommufd_test_access_rw.isra.0+0x2ec/0x390 |
| iommufd_test+0x1058/0x1e30 |
| iommufd_fops_ioctl+0x381/0x510 |
| vfs_ioctl |
| __do_sys_ioctl |
| __se_sys_ioctl |
| __x64_sys_ioctl+0x170/0x1e0 |
| do_syscall_x64 |
| do_syscall_64+0x71/0x140 |
| |
| This is because the new iommufd_access_change_ioas() sets access->ioas to |
| NULL during its process, so the lock might be gone in a concurrent racing |
| context. |
| |
| Fix this by doing the same access->ioas sanity as iommufd_access_rw() and |
| iommufd_access_pin_pages() functions do. |
| |
| The Linux kernel CVE team has assigned CVE-2024-26785 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 6.6 with commit 9227da7816dd1a42e20d41e2244cb63c205477ca and fixed in 6.6.55 with commit fd4d5cd7a2e8f08357c9bfc0905957cffe8ce568 |
| Issue introduced in 6.6 with commit 9227da7816dd1a42e20d41e2244cb63c205477ca and fixed in 6.7.9 with commit fc719ecbca45c9c046640d72baddba3d83e0bc0b |
| Issue introduced in 6.6 with commit 9227da7816dd1a42e20d41e2244cb63c205477ca and fixed in 6.8 with commit cf7c2789822db8b5efa34f5ebcf1621bc0008d48 |
| |
| 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-2024-26785 |
| 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/iommufd/selftest.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/fd4d5cd7a2e8f08357c9bfc0905957cffe8ce568 |
| https://git.kernel.org/stable/c/fc719ecbca45c9c046640d72baddba3d83e0bc0b |
| https://git.kernel.org/stable/c/cf7c2789822db8b5efa34f5ebcf1621bc0008d48 |
