{ "affected": [ { "ranges": [ { "events": [ { "introduced": "30ea32ab1951c80c6113f300fce2c70cd12659e4" }, { "fixed": "eb84cd81040e58dd05ac190f561f2115e3367249" }, { "fixed": "f0eea8f9013676b42289ec35941e848b8a543e19" }, { "fixed": "d665a1688af7f8fefd7c0eb04f2a37122ce007f4" }, { "fixed": "25cdd2a492d868cff1e519a60fe282909c52d385" }, { "fixed": "812f1db7f0755a19ef16ecdc5cec51bcabc5eda5" }, { "fixed": "533d0c5feef85ee6404b9f41d5564fac6971a008" }, { "fixed": "fda8fb7e8179561693a786a7af593f6b944a21c1" }, { "fixed": "dc77acfeb979dded39b247b60fef0399536bfa77" } ], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "type": "GIT" }, { "events": [ { "introduced": "0" }, { "last_affected": "ac370e3d1f3b01519d2705cd5815d1c9d0a8812b" }, { "last_affected": "be363e27ec3c3a99793da2be6c07eafb95709c6b" }, { "last_affected": "f1b10ba5739440ca51d66f0b2949cead88d2dd02" }, { "last_affected": "dde3433de9a067a33d67d65b9093cad3e043e49e" } ], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "type": "GIT" }, { "events": [ { "introduced": "4.4.203" }, { "fixed": "4.5" } ], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "type": "GIT" }, { "events": [ { "introduced": "4.9.203" }, { "fixed": "4.10" } ], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "type": "GIT" }, { "events": [ { "introduced": "4.14.155" }, { "fixed": "4.15" } ], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "type": "GIT" }, { "events": [ { "introduced": "4.19.85" }, { "fixed": "4.20" } ], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "type": "GIT" } ] }, { "package": { "ecosystem": "Linux", "name": "Kernel" }, "ranges": [ { "events": [ { "introduced": "4.20.0" }, { "fixed": "5.10.270" } ], "type": "ECOSYSTEM" }, { "events": [ { "introduced": "5.11.0" }, { "fixed": "5.15.221" } ], "type": "ECOSYSTEM" }, { "events": [ { "introduced": "5.16.0" }, { "fixed": "6.1.188" } ], "type": "ECOSYSTEM" }, { "events": [ { "introduced": "6.2.0" }, { "fixed": "6.6.157" } ], "type": "ECOSYSTEM" }, { "events": [ { "introduced": "6.7.0" }, { "fixed": "6.12.110" } ], "type": "ECOSYSTEM" }, { "events": [ { "introduced": "6.13.0" }, { "fixed": "6.18.52" } ], "type": "ECOSYSTEM" }, { "events": [ { "introduced": "6.19.0" }, { "fixed": "7.2.6" } ], "type": "ECOSYSTEM" } ] } ], "database_specific": { "cna_assigner": "Linux", "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89777.json" }, "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nvfio/pci: clear vdev-\u003emsi_perm after freeing it on init failure\n\nvfio_msi_cap_len() lazily allocates the per-device MSI permission table:\n\n\tvdev-\u003emsi_perm = kmalloc_obj(struct perm_bits, GFP_KERNEL_ACCOUNT);\n\tif (!vdev-\u003emsi_perm)\n\t\treturn -ENOMEM;\n\n\tret = init_pci_cap_msi_perm(vdev-\u003emsi_perm, len, flags);\n\tif (ret) {\n\t\tkfree(vdev-\u003emsi_perm);\n\t\treturn ret;\t\t/* vdev-\u003emsi_perm left dangling */\n\t}\n\nWhen init_pci_cap_msi_perm() -\u003e alloc_perm_bits() fails with -ENOMEM, the\nerror path frees vdev-\u003emsi_perm but leaves the freed pointer stored in\nit. vdev-\u003emsi_perm is not re-zeroed later because struct\nvfio_pci_core_device is per-device and persists across open/close cycles,\nand the vfio_config_init() error path returns without calling\nvfio_config_free(). So the dangling pointer outlives the failed open.\n\nThat leads to two use-after-frees on the same device:\n\n1. Reuse. The next vfio_config_init() sees the stale pointer at\n \"if (vdev-\u003emsi_perm) return len;\" and reuses the freed object. MSI\n config accesses in vfio_pci_config_rw_single() then dereference and\n call the freed perm-\u003ereadfn / perm-\u003ewritefn function pointers.\n\n2. Double free. A later vfio_config_free() runs free_perm_bits() and\n kfree() on the already-freed object.\n\nFix it by NULLing vdev-\u003emsi_perm after the kfree(), matching the\nNULL-after-free discipline already used in free_perm_bits() and\nvfio_config_free().\n\n BUG: KASAN: slab-use-after-free in vfio_pci_config_rw_single (drivers/vfio/pci/vfio_pci_config.c:1961)\n Read of size 8 at addr ffff88800fcc88d0 by task exploit/143\n Call Trace:\n ...\n kasan_report (mm/kasan/report.c:595)\n vfio_pci_config_rw_single (drivers/vfio/pci/vfio_pci_config.c:1961)\n vfio_pci_config_rw (drivers/vfio/pci/vfio_pci_config.c:1986)\n vfio_pci_rw (drivers/vfio/pci/vfio_pci_core.c:1599)\n vfs_read (fs/read_write.c:572)\n __x64_sys_pread64 (fs/read_write.c:764)\n do_syscall_64 (arch/x86/entry/syscall_64.c:94)\n ...\n\nFollowed on device close by a double free of the same object:\n\n Oops: general protection fault, probably for non-canonical address\n 0x1f63e0e8000008: 0000 [#1] SMP KASAN NOPTI\n RIP: 0010:kfree (mm/slub.c:6711)\n Call Trace:\n vfio_config_free (drivers/vfio/pci/vfio_pci_config.c:1861)\n vfio_pci_core_disable (drivers/vfio/pci/vfio_pci_core.c:685)\n vfio_pci_core_close_device (drivers/vfio/pci/vfio_pci_core.c:777)\n vfio_df_close (drivers/vfio/vfio_main.c:602)\n vfio_device_fops_release (drivers/vfio/vfio_main.c:648)\n __fput (fs/file_table.c:512)\n __x64_sys_close (fs/open.c:1496)\n do_syscall_64 (arch/x86/entry/syscall_64.c:94)\n ...\n Kernel panic - not syncing: Fatal exception", "id": "CVE-2026-89777", "modified": "2026-09-18T03:30:55.483360012Z", "published": "2026-09-16T08:48:17.754Z", "references": [ { "type": "WEB", "url": "https://git.kernel.org/stable/c/25cdd2a492d868cff1e519a60fe282909c52d385" }, { "type": "WEB", "url": "https://git.kernel.org/stable/c/533d0c5feef85ee6404b9f41d5564fac6971a008" }, { "type": "WEB", "url": "https://git.kernel.org/stable/c/812f1db7f0755a19ef16ecdc5cec51bcabc5eda5" }, { "type": "WEB", "url": "https://git.kernel.org/stable/c/d665a1688af7f8fefd7c0eb04f2a37122ce007f4" }, { "type": "WEB", "url": "https://git.kernel.org/stable/c/dc77acfeb979dded39b247b60fef0399536bfa77" }, { "type": "WEB", "url": "https://git.kernel.org/stable/c/eb84cd81040e58dd05ac190f561f2115e3367249" }, { "type": "WEB", "url": "https://git.kernel.org/stable/c/f0eea8f9013676b42289ec35941e848b8a543e19" }, { "type": "WEB", "url": "https://git.kernel.org/stable/c/fda8fb7e8179561693a786a7af593f6b944a21c1" }, { "type": "ADVISORY", "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89777.json" }, { "type": "ADVISORY", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-89777" }, { "type": "PACKAGE", "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git" } ], "schema_version": "1.9.0", "severity": [ { "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H", "type": "CVSS_V3" } ], "summary": "vfio/pci: clear vdev-\u003emsi_perm after freeing it on init failure" }