GHSA-HGGW-GJV7-4223
Vulnerability from github – Published: 2026-08-15 06:32 – Updated: 2026-08-17 06:33In the Linux kernel, the following vulnerability has been resolved:
nvme-multipath: fix flex array size in struct nvme_ns_head
struct nvme_ns_head contains a flexible array member, current_path[], which is indexed using the NUMA node ID: head->current_path[numa_node_id()]
The structure is currently allocated as: size = sizeof(struct nvme_ns_head) + (num_possible_nodes() * sizeof(struct nvme_ns *)); head = kzalloc(size, GFP_KERNEL);
This allocation assumes that NUMA node IDs are sequential and densely packed from 0 .. num_possible_nodes() - 1. While this assumption holds on many systems, it is not always true on some architectures such as powerpc.
On some powerpc systems, NUMA node IDs can be sparse. For example: NUMA: NUMA node(s): 6 NUMA node0 CPU(s): 80-159 NUMA node8 CPU(s): 0-79 NUMA node252 CPU(s): NUMA node253 CPU(s): NUMA node254 CPU(s): NUMA node255 CPU(s):
That is, the possible/online NUMA node IDs are: 0, 8, 252, 253, 254, 255 In this case: num_possible_nodes() = 6
So memory is allocated for only 6 entries in current_path[]. However, the array is later indexed using the actual NUMA node ID. As a result, accesses such as: head->current_path[8] or head->current_path[252] goes out of bounds, leading to the following KASAN splat:
================================================================== BUG: KASAN: slab-out-of-bounds in nvme_mpath_revalidate_paths+0x22c/0x290 [nvme_core] Write of size 8 at addr c00020003bda35b8 by task kworker/u641:2/1997
CPU: 1 UID: 0 PID: 1997 Comm: kworker/u641:2 Not tainted 7.1.0-rc5-dirty #14 PREEMPT(lazy) Hardware name: 8335-GTH POWER9 0x4e1202 opal:skiboot-v6.5.3-35-g1851b2a06 PowerNV Workqueue: async async_run_entry_fn Call Trace: [c000200037fa7510] [c0000000021c23d4] dump_stack_lvl+0x88/0xdc (unreliable) [c000200037fa7540] [c0000000009fda90] print_report+0x22c/0x67c [c000200037fa7630] [c0000000009fd508] kasan_report+0x108/0x220 [c000200037fa7740] [c0000000009fff48] __asan_store8+0xe8/0x120 [c000200037fa7760] [c008000018e76474] nvme_mpath_revalidate_paths+0x22c/0x290 [nvme_core] [c000200037fa7800] [c008000018e6556c] nvme_update_ns_info+0x4a4/0x5e0 [nvme_core] [c000200037fa7a50] [c008000018e66270] nvme_alloc_ns+0x6d8/0x1a70 [nvme_core] [c000200037fa7c20] [c008000018e679fc] nvme_scan_ns+0x3f4/0x630 [nvme_core] [c000200037fa7d10] [c00000000031f22c] async_run_entry_fn+0x9c/0x3a0 [c000200037fa7db0] [c0000000002fa544] process_one_work+0x414/0xa10 [c000200037fa7ec0] [c0000000002fbf00] worker_thread+0x320/0x640 [c000200037fa7f80] [c00000000030d0f8] kthread+0x278/0x290 [c000200037fa7fe0] [c00000000000ded8] start_kernel_thread+0x14/0x18
Allocated by task 1997 on cpu 1 at 35.928317s:
The buggy address belongs to the object at c00020003bda3000 which belongs to the cache kmalloc-rnd-15-2k of size 2048 The buggy address is located 16 bytes to the right of allocated 1448-byte region [c00020003bda3000, c00020003bda35a8)
The buggy address belongs to the physical page:
Memory state around the buggy address: c00020003bda3480: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 c00020003bda3500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
c00020003bda3580: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc ^ c00020003bda3600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc c00020003bda3680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================
Fix this by allocating the flexible array using nr_node_ids instead of num_possible_nodes(). Since nr_node_ids represents the maximum possible NUMA node IDs, indexing current_path[] using numa_node_id() becomes safe even on systems with sparse node IDs.
{
"affected": [],
"aliases": [
"CVE-2026-74384"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-08-15T06:22:40Z",
"severity": "CRITICAL"
},
"details": "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-\u003ecurrent_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-\u003ecurrent_path[8] or\nhead-\u003ecurrent_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\u003ec00020003bda3580: 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.",
"id": "GHSA-hggw-gjv7-4223",
"modified": "2026-08-17T06:33:42Z",
"published": "2026-08-15T06:32:32Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-74384"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/001e57554de81aa79c25c18fd53911d8a415c304"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/140d6fff4ed266592492a23444043842b4af7a62"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/1d4131b5c9823c7d2c86389898ad1b466af7df5e"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/316b5f1168264844aa125959de1d6da2b1905795"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/7173a741fed73de6247384056fe92e582ba12507"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/7e7b167e65610dfa7564d449474f4b477f9d4c1c"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/9ffdd11bd6c961b46b3689850ff6c5d7af5c5fe5"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/bde4d6eb53f7d3cdae7e62c9ee84345fdd6e70a6"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.