From bippy-851b3ed3d212 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman To: Reply-to: , Subject: CVE-2024-26786: iommufd: Fix iopt_access_list_id overwrite bug Description =========== In the Linux kernel, the following vulnerability has been resolved: iommufd: Fix iopt_access_list_id overwrite bug Syzkaller reported the following WARN_ON: WARNING: CPU: 1 PID: 4738 at drivers/iommu/iommufd/io_pagetable.c:1360 Call Trace: iommufd_access_change_ioas+0x2fe/0x4e0 iommufd_access_destroy_object+0x50/0xb0 iommufd_object_remove+0x2a3/0x490 iommufd_object_destroy_user iommufd_access_destroy+0x71/0xb0 iommufd_test_staccess_release+0x89/0xd0 __fput+0x272/0xb50 __fput_sync+0x4b/0x60 __do_sys_close __se_sys_close __x64_sys_close+0x8b/0x110 do_syscall_x64 The mismatch between the access pointer in the list and the passed-in pointer is resulting from an overwrite of access->iopt_access_list_id, in iopt_add_access(). Called from iommufd_access_change_ioas() when xa_alloc() succeeds but iopt_calculate_iova_alignment() fails. Add a new_id in iopt_add_access() and only update iopt_access_list_id when returning successfully. The Linux kernel CVE team has assigned CVE-2024-26786 to this issue. Affected and fixed versions =========================== Issue introduced in 6.6 with commit 9227da7816dd and fixed in 6.6.21 with commit f1fb745ee0a6 Issue introduced in 6.6 with commit 9227da7816dd and fixed in 6.7.9 with commit 9526a46cc0c3 Issue introduced in 6.6 with commit 9227da7816dd and fixed in 6.8 with commit aeb004c0cd69 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-2024-26786 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/io_pagetable.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/f1fb745ee0a6fe43f1d84ec369c7e6af2310fda9 https://git.kernel.org/stable/c/9526a46cc0c378d381560279bea9aa34c84298a0 https://git.kernel.org/stable/c/aeb004c0cd6958e910123a1607634401009c9539