{"cve":"CVE-2026-80817","nvd":{"published":"2026-09-04T16:18:09.303","modified":"2026-10-19T09:17:16.590","status":"Received","description":"In the Linux kernel, the following vulnerability has been resolved:\n\niommu/iommufd: Fix NULL pointer deref in iommufd_ioas_change_process when racing with iopt_map_file_pages\n\niommufd_ioas_change_process() iterates every IOAS area while only\nholding every IOAS iova_rwsem, so it assumes every area has a non-NULL\npages pointer. That assumption can be false when it runs concurrently\nwith iopt_map_file_pages().\n\niopt_map_pages() executes in two phases. It first creates the area and\ninserts it into the interval tree under iova_rwsem, with area->pages\nstill NULL. It then drops iova_rwsem and later fills area->pages\nunder domains_rwsem. This leaves a window between area creation and\narea->pages fill where a concurrent iommufd_ioas_change_process()\ncan observe the area and dereference a NULL area->pages pointer,\nleading to a NULL pointer dereference:\n\nBUG: kernel NULL pointer dereference, address: 00000000000000c0\n#PF: supervisor read access in kernel mode\n#PF: error_code(0x0000) - not-present page\nPGD 4b655067 P4D 4b655067 PUD 0\nOops: Oops: 0000 [#1] SMP NOPTI\nCPU: 0 UID: 0 PID: 11841 Comm: syz.1.628 Not tainted 7.1.0 #3 PREEMPT(full)\nHardware name: QEMU Ubuntu 24.04 PC v2 (i440FX + PIIX, arch_caps fix, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014\nRIP: 0010:iommufd_ioas_change_process+0x419/0xd50 drivers/iommu/iommufd/ioas.c:538\nCode: 48 89 c3 48 85 c0 0f 84 cc 00 00 00 e8 10 f5 cb fd 48 8d 7b 68 e8 a7 b5 eb fd 48 8b 6b 68 48 8d bd c0 00 00 00 e8 17 b2 eb fd <8b> ad c0 00 00 00 bf 01 00 00 00 89 ee e8 85 ef cb fd 83 fd 01 74\nRSP: 0018:ffffc90015c17d28 EFLAGS: 00010246\nRAX: ffff8880186d5328 RBX: ffff88801d25e240 RCX: 0000000080000000\nRDX: 00000000000002d7 RSI: ffffffff83ba9e10 RDI: 00000000000000c0\nRBP: 0000000000000000 R08: ffffffff8e781eb8 R09: 0000000000000000\nR10: 00000000000000c0 R11: ffffffff83ba9e29 R12: ffff88802e216008\nR13: ffff88802e216000 R14: 0000000000000001 R15: 0000000000000000\nFS:  00007f4aea3f66c0(0000) GS:ffff8880b1fa1000(0000) knlGS:0000000000000000\nCS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\nCR2: 00000000000000c0 CR3: 000000004b75c000 CR4: 0000000000350ef0\nCall Trace:\n <TASK>\n iommufd_fops_ioctl+0x287/0x400 drivers/iommu/iommufd/main.c:533\n vfs_ioctl fs/ioctl.c:51 [inline]\n __do_sys_ioctl fs/ioctl.c:597 [inline]\n __se_sys_ioctl fs/ioctl.c:583 [inline]\n __x64_sys_ioctl+0x120/0x170 fs/ioctl.c:583\n x64_sys_call+0x1092/0x1fb0 arch/x86/include/generated/asm/syscalls_64.h:17\n do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n do_syscall_64+0x10a/0x680 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\nRIP: 0033:0x7f4aec1a82bd\nCode: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48\nRSP: 002b:00007f4aea3f6018 EFLAGS: 00000246 ORIG_RAX: 0000000000000010\nRAX: ffffffffffffffda RBX: 00007f4aec436090 RCX: 00007f4aec1a82bd\nRDX: 0000200000000180 RSI: 0000000000003b92 RDI: 0000000000000003\nRBP: 00007f4aec250295 R08: 0000000000000000 R09: 0000000000000000\nR10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000\nR13: 00007f4aec436128 R14: 00007f4aec436090 R15: 00007ffd04ef23e0\n </TASK>\nModules linked in:\nCR2: 00000000000000c0\n---[ end trace 0000000000000000 ]---\nRIP: 0010:iommufd_ioas_change_process+0x419/0xd50 drivers/iommu/iommufd/ioas.c:538\nCode: 48 89 c3 48 85 c0 0f 84 cc 00 00 00 e8 10 f5 cb fd 48 8d 7b 68 e8 a7 b5 eb fd 48 8b 6b 68 48 8d bd c0 00 00 00 e8 17 b2 eb fd <8b> ad c0 00 00 00 bf 01 00 00 00 89 ee e8 85 ef cb fd 83 fd 01 74\nRSP: 0018:ffffc90015c17d28 EFLAGS: 00010246\nRAX: ffff8880186d5328 RBX: ffff88801d25e240 RCX: 0000000080000000\nRDX: 00000000000002d7 RSI: ffffffff83ba9e10 RDI: 00000000000000c0\nRBP: 0000000000000000 R08: ffffffff8e781eb8 R09: 0000000000000000\nR10: 00000000000000c0 R11: ffffffff83ba9e29 R12: ffff88802e216008\nR13: ffff88802e216000 R14: 0000000000000001 R15: 0000000000000000\nFS:  00007f4aea3f66c0(000\n---truncated---","cvss_v4":null,"cvss_v3":null,"cwes":[],"references":["https://git.kernel.org/stable/c/7596354148c5aa12dfaa17992d1aef1aa2ea831a","https://git.kernel.org/stable/c/d616de490ec0242dcf78f02f1adf7baa035c4d0d","https://git.kernel.org/stable/c/d9635e2507dc8260b9ba9992a4198e84f9340a15","https://git.kernel.org/stable/c/ffe6d379be20df013e19a4c63dd80bc6b683106d"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:52:03.409947763+00:00"},"epss":{"cve":"CVE-2026-80817","score":0.00209,"percentile":0.10902,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}