{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-46029",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2026-05-13T15:03:33.093Z",
        "datePublished": "2026-05-27T12:56:38.376Z",
        "dateUpdated": "2026-08-05T12:29:13.390Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-08-05T12:29:13.390Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/slab: return NULL early from kmalloc_nolock() in NMI on UP\n\nOn UP kernels (!CONFIG_SMP), spin_trylock() is a no-op that\nunconditionally succeeds even when the lock is already held. As a\nresult, kmalloc_nolock() called from NMI context can re-enter the slab\nallocator and acquire n->list_lock that the interrupted context is\nalready holding, corrupting slab state.\n\nWith CONFIG_DEBUG_SPINLOCK on UP, the following BUG is triggered with\nthe slub_kunit test module:\n\n  BUG: spinlock trylock failure on UP on CPU#0, kunit_try_catch/243\n  [...]\n  Call Trace:\n   <NMI>\n   dump_stack_lvl+0x3f/0x60\n   do_raw_spin_trylock+0x41/0x50\n   _raw_spin_trylock+0x24/0x50\n   get_from_partial_node+0x120/0x4d0\n   ___slab_alloc+0x8a/0x4c0\n   kmalloc_nolock_noprof+0x164/0x310\n   [...]\n   </NMI>\n\nFix this by returning NULL early when invoked from NMI on a UP kernel."
                }
            ],
            "metrics": [
                {
                    "cvssV3_1": {
                        "version": "3.1",
                        "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H",
                        "baseScore": 7,
                        "baseSeverity": "HIGH"
                    },
                    "scenarios": [
                        {
                            "lang": "en",
                            "value": "AV:L - The only callers reaching NMI-context kmalloc_nolock() are local BPF programs (perf events) or in-kernel module code; there is no remote/network path to this allocator routine.\nAC:H - The bug only manifests on rare non-default uniprocessor (!CONFIG_SMP) kernels, and additionally requires the NMI to fire during the narrow window in which the interrupted context holds n->list_lock — both conditions are beyond the attacker's control.\nPR:L - Running code in NMI context that calls kmalloc_nolock() requires attaching a BPF program to a hardware perf event (CAP_BPF/CAP_PERFMON), which are sub-root capabilities delegable to confined tracing/profiling service accounts rather than full root.\nUI:N - Triggering the NMI-context allocation requires no action from any other user or victim.\nS:U - The slab-state corruption stays within the kernel's own security authority; no cross-boundary (VM/IOMMU) escape is involved.\nC:H - Re-entrant slab list/freelist corruption is a powerful primitive that can produce overlapping allocations and be leveraged for kernel memory disclosure.\nI:H - Corruption of SLUB partial-list/freelist metadata is a well-known basis for arbitrary-write primitives and control-flow hijacking.\nA:H - The corrupted slab state (or the DEBUG_SPINLOCK BUG) leads to kernel oops/panic, a full availability loss."
                        }
                    ]
                }
            ],
            "affected": [
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "mm/slub.c"
                    ],
                    "versions": [
                        {
                            "version": "af92793e52c3a99b828ed4bdd277fd3e11c18d08",
                            "lessThan": "a8d95d274be241ad21f6523bf2d6ba0d7d7e46b7",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "af92793e52c3a99b828ed4bdd277fd3e11c18d08",
                            "lessThan": "d66553204a15bdb257d9ef8aca1e12f5fbb910b2",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "af92793e52c3a99b828ed4bdd277fd3e11c18d08",
                            "lessThan": "5b31044e649e3e54c2caef135c09b371c2fbcd08",
                            "status": "affected",
                            "versionType": "git"
                        }
                    ]
                },
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "affected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "mm/slub.c"
                    ],
                    "versions": [
                        {
                            "version": "6.18",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "6.18",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.18.27",
                            "lessThanOrEqual": "6.18.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.0.4",
                            "lessThanOrEqual": "7.0.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.1",
                            "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": "6.18",
                                    "versionEndExcluding": "6.18.27"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "6.18",
                                    "versionEndExcluding": "7.0.4"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "6.18",
                                    "versionEndExcluding": "7.1"
                                }
                            ]
                        }
                    ]
                }
            ],
            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/a8d95d274be241ad21f6523bf2d6ba0d7d7e46b7"
                },
                {
                    "url": "https://git.kernel.org/stable/c/d66553204a15bdb257d9ef8aca1e12f5fbb910b2"
                },
                {
                    "url": "https://git.kernel.org/stable/c/5b31044e649e3e54c2caef135c09b371c2fbcd08"
                }
            ],
            "title": "mm/slab: return NULL early from kmalloc_nolock() in NMI on UP",
            "x_generator": {
                "engine": "bippy-1.2.0"
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}