{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-74384", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-15T05:44:03.890Z", "datePublished": "2026-08-15T05:59:00.445Z", "dateUpdated": "2026-08-17T05:46:34.280Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-17T05:46:34.280Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnvme-multipath: fix flex array size in struct nvme_ns_head\n\nstruct nvme_ns_head contains a flexible array member, current_path[],\nwhich is indexed using the NUMA node ID:\nhead->current_path[numa_node_id()]\n\nThe structure is currently allocated as:\nsize = sizeof(struct nvme_ns_head) +\n (num_possible_nodes() * sizeof(struct nvme_ns *));\nhead = kzalloc(size, GFP_KERNEL);\n\nThis allocation assumes that NUMA node IDs are sequential and densely\npacked from 0 .. num_possible_nodes() - 1. While this assumption holds\non many systems, it is not always true on some architectures such as\npowerpc.\n\nOn some powerpc systems, NUMA node IDs can be sparse. For example:\nNUMA:\n NUMA node(s): 6\n NUMA node0 CPU(s): 80-159\n NUMA node8 CPU(s): 0-79\n NUMA node252 CPU(s):\n NUMA node253 CPU(s):\n NUMA node254 CPU(s):\n NUMA node255 CPU(s):\n\nThat is, the possible/online NUMA node IDs are: 0, 8, 252, 253, 254, 255\nIn this case: num_possible_nodes() = 6\n\nSo memory is allocated for only 6 entries in current_path[]. However,\nthe array is later indexed using the actual NUMA node ID. As a result,\naccesses such as:\nhead->current_path[8] or\nhead->current_path[252]\ngoes out of bounds, leading to the following KASAN splat:\n\n==================================================================\nBUG: KASAN: slab-out-of-bounds in nvme_mpath_revalidate_paths+0x22c/0x290 [nvme_core]\nWrite of size 8 at addr c00020003bda35b8 by task kworker/u641:2/1997\n\nCPU: 1 UID: 0 PID: 1997 Comm: kworker/u641:2 Not tainted 7.1.0-rc5-dirty #14 PREEMPT(lazy)\nHardware name: 8335-GTH POWER9 0x4e1202 opal:skiboot-v6.5.3-35-g1851b2a06 PowerNV\nWorkqueue: async async_run_entry_fn\nCall Trace:\n[c000200037fa7510] [c0000000021c23d4] dump_stack_lvl+0x88/0xdc (unreliable)\n[c000200037fa7540] [c0000000009fda90] print_report+0x22c/0x67c\n[c000200037fa7630] [c0000000009fd508] kasan_report+0x108/0x220\n[c000200037fa7740] [c0000000009fff48] __asan_store8+0xe8/0x120\n[c000200037fa7760] [c008000018e76474] nvme_mpath_revalidate_paths+0x22c/0x290 [nvme_core]\n[c000200037fa7800] [c008000018e6556c] nvme_update_ns_info+0x4a4/0x5e0 [nvme_core]\n[c000200037fa7a50] [c008000018e66270] nvme_alloc_ns+0x6d8/0x1a70 [nvme_core]\n[c000200037fa7c20] [c008000018e679fc] nvme_scan_ns+0x3f4/0x630 [nvme_core]\n[c000200037fa7d10] [c00000000031f22c] async_run_entry_fn+0x9c/0x3a0\n[c000200037fa7db0] [c0000000002fa544] process_one_work+0x414/0xa10\n[c000200037fa7ec0] [c0000000002fbf00] worker_thread+0x320/0x640\n[c000200037fa7f80] [c00000000030d0f8] kthread+0x278/0x290\n[c000200037fa7fe0] [c00000000000ded8] start_kernel_thread+0x14/0x18\n\nAllocated by task 1997 on cpu 1 at 35.928317s:\n\nThe buggy address belongs to the object at c00020003bda3000\n which belongs to the cache kmalloc-rnd-15-2k of size 2048\nThe buggy address is located 16 bytes to the right of\n allocated 1448-byte region [c00020003bda3000, c00020003bda35a8)\n\nThe buggy address belongs to the physical page:\n\nMemory state around the buggy address:\n c00020003bda3480: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00\n c00020003bda3500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00\n>c00020003bda3580: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc\n ^\n c00020003bda3600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc\n c00020003bda3680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc\n==================================================================\n\nFix this by allocating the flexible array using nr_node_ids instead\nof num_possible_nodes(). Since nr_node_ids represents the maximum\npossible NUMA node IDs, indexing current_path[] using numa_node_id()\nbecomes safe even on systems with sparse node IDs." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 9.8, "baseSeverity": "CRITICAL" }, "scenarios": [ { "lang": "en", "value": "AV:N - On IBM POWER cloud/enterprise hosts using NVMe-oF (TCP/RDMA/FC), a remote attacker on the storage fabric can deliver NVMe async namespace-changed completions that queue namespace rescans, driving nvme_scan_ns()→nvme_alloc_ns()→nvme_update_ns_info()→nvme_mpath_revalidate_paths() over the network-facing NVMe host transport.\nAC:L - Once CONFIG_NVME_MULTIPATH is enabled on POWER systems with sparse NUMA IDs (e.g., nodes 0,8,252-255), indexing current_path[numa_node_id()] deterministically exceeds the num_possible_nodes()-sized allocation during boot scan, admin rescan, or multipath I/O without races or layout luck.\nPR:N - Triggering the bug via remote NVMe async events or normal multipath block I/O requires no local account, CAP_SYS_ADMIN, or other host privileges; only an existing NVMe attachment (local PCIe or preconfigured fabric) on a vulnerable POWER NUMA topology.\nUI:N - No victim user action is required beyond routine system operation such as boot-time namespace discovery, background kworker rescans, or ordinary storage I/O on multipathed NVMe namespaces.\nS:U - The out-of-bounds slab write corrupts host kernel heap memory in the NVMe multipath driver, enabling kernel privilege escalation within the same security authority rather than crossing VM, container, or IOMMU boundaries.\nC:H - KASAN reports an 8-byte slab-out-of-bounds write past the nvme_ns_head allocation; this heap corruption can overwrite adjacent kmalloc objects and be developed into arbitrary kernel memory disclosure primitives.\nI:H - The unchecked current_path[] index allows attacker-influenced 8-byte pointer writes beyond the allocation boundary, providing a heap corruption primitive suitable for arbitrary kernel writes and potential code execution.\nA:H - The confirmed slab-out-of-bounds write in nvme_mpath_revalidate_paths() can oops/panic the kernel during namespace scan or multipath I/O on affected POWER servers, causing complete node unavailability." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/nvme/host/core.c" ], "versions": [ { "version": "f333444708f82c4a4d3ccac004da0bfd9cfdfa42", "lessThan": "7e7b167e65610dfa7564d449474f4b477f9d4c1c", "status": "affected", "versionType": "git" }, { "version": "f333444708f82c4a4d3ccac004da0bfd9cfdfa42", "lessThan": "316b5f1168264844aa125959de1d6da2b1905795", "status": "affected", "versionType": "git" }, { "version": "f333444708f82c4a4d3ccac004da0bfd9cfdfa42", "lessThan": "1d4131b5c9823c7d2c86389898ad1b466af7df5e", "status": "affected", "versionType": "git" }, { "version": "f333444708f82c4a4d3ccac004da0bfd9cfdfa42", "lessThan": "9ffdd11bd6c961b46b3689850ff6c5d7af5c5fe5", "status": "affected", "versionType": "git" }, { "version": "f333444708f82c4a4d3ccac004da0bfd9cfdfa42", "lessThan": "bde4d6eb53f7d3cdae7e62c9ee84345fdd6e70a6", "status": "affected", "versionType": "git" }, { "version": "f333444708f82c4a4d3ccac004da0bfd9cfdfa42", "lessThan": "140d6fff4ed266592492a23444043842b4af7a62", "status": "affected", "versionType": "git" }, { "version": "f333444708f82c4a4d3ccac004da0bfd9cfdfa42", "lessThan": "7173a741fed73de6247384056fe92e582ba12507", "status": "affected", "versionType": "git" }, { "version": "f333444708f82c4a4d3ccac004da0bfd9cfdfa42", "lessThan": "001e57554de81aa79c25c18fd53911d8a415c304", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/nvme/host/core.c" ], "versions": [ { "version": "4.20", "status": "affected" }, { "version": "0", "lessThan": "4.20", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.261", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.212", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.178", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.145", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.97", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.40", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.5", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.20", "versionEndExcluding": "5.10.261" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.20", "versionEndExcluding": "5.15.212" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.20", "versionEndExcluding": "6.1.178" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.20", "versionEndExcluding": "6.6.145" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.20", "versionEndExcluding": "6.12.97" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.20", "versionEndExcluding": "6.18.40" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.20", "versionEndExcluding": "7.1.5" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.20", "versionEndExcluding": "7.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/7e7b167e65610dfa7564d449474f4b477f9d4c1c" }, { "url": "https://git.kernel.org/stable/c/316b5f1168264844aa125959de1d6da2b1905795" }, { "url": "https://git.kernel.org/stable/c/1d4131b5c9823c7d2c86389898ad1b466af7df5e" }, { "url": "https://git.kernel.org/stable/c/9ffdd11bd6c961b46b3689850ff6c5d7af5c5fe5" }, { "url": "https://git.kernel.org/stable/c/bde4d6eb53f7d3cdae7e62c9ee84345fdd6e70a6" }, { "url": "https://git.kernel.org/stable/c/140d6fff4ed266592492a23444043842b4af7a62" }, { "url": "https://git.kernel.org/stable/c/7173a741fed73de6247384056fe92e582ba12507" }, { "url": "https://git.kernel.org/stable/c/001e57554de81aa79c25c18fd53911d8a415c304" } ], "title": "nvme-multipath: fix flex array size in struct nvme_ns_head", "x_generator": { "engine": "bippy-1.2.0" } } } }