CVE-2026-45990

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-45990", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-05-13T15:03:33.091Z", "datePublished": "2026-05-27T12:55:42.572Z", "dateUpdated": "2026-06-14T17:46:45.762Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-06-14T17:46:45.762Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nslub: fix data loss and overflow in krealloc()\n\nCommit 2cd8231796b5 (\"mm/slub: allow to set node and align in\nk[v]realloc\") introduced the ability to force a reallocation if the\noriginal object does not satisfy new alignment or NUMA node, even when\nthe object is being shrunk.\n\nThis introduced two bugs in the reallocation fallback path:\n\n1. Data loss during NUMA migration: The jump to 'alloc_new' happens\n before 'ks' and 'orig_size' are initialized. As a result, the\n memcpy() in the 'alloc_new' block would copy 0 bytes into the new\n allocation.\n\n2. Buffer overflow during shrinking: When shrinking an object while\n forcing a new alignment, 'new_size' is smaller than the old size.\n However, the memcpy() used the old size ('orig_size ?: ks'), leading\n to an out-of-bounds write.\n\nThe same overflow bug exists in the kvrealloc() fallback path, where the\nold bucket size ksize(p) is copied into the new buffer without being\nbounded by the new size.\n\nA simple reproducer:\n\n\t// e.g. add to lkdtm as KREALLOC_SHRINK_OVERFLOW\n\twhile (1) {\n\t\tvoid *p = kmalloc(128, GFP_KERNEL);\n\t\tp = krealloc_node_align(p, 64, 256, GFP_KERNEL, NUMA_NO_NODE);\n\t\tkfree(p);\n\t}\n\ndemonstrates the issue:\n\n ==================================================================\n BUG: KFENCE: out-of-bounds write in memcpy_orig+0x68/0x130\n\n Out-of-bounds write at 0xffff8883ad757038 (120B right of kfence-#47):\n memcpy_orig+0x68/0x130\n krealloc_node_align_noprof+0x1c8/0x340\n lkdtm_KREALLOC_SHRINK_OVERFLOW+0x8c/0xc0 [lkdtm]\n lkdtm_do_action+0x3a/0x60 [lkdtm]\n ...\n\n kfence-#47: 0xffff8883ad756fc0-0xffff8883ad756fff, size=64, cache=kmalloc-64\n\n allocated by task 316 on cpu 7 at 97.680481s (0.021813s ago):\n krealloc_node_align_noprof+0x19c/0x340\n lkdtm_KREALLOC_SHRINK_OVERFLOW+0x8c/0xc0 [lkdtm]\n lkdtm_do_action+0x3a/0x60 [lkdtm]\n ...\n ==================================================================\n\nFix it by moving the old size calculation to the top of __do_krealloc()\nand bounding all copy lengths by the new allocation size."}], "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": "2cd8231796b5e7133b1c3d66ad7d2a3c42c97258", "lessThan": "38387ccc0fbe38d14fb4c2ad7ee1d7404e5e59fd", "status": "affected", "versionType": "git"}, {"version": "2cd8231796b5e7133b1c3d66ad7d2a3c42c97258", "lessThan": "550fa6b5aabb096554536ac1e3ec96b76cbb35fd", "status": "affected", "versionType": "git"}, {"version": "2cd8231796b5e7133b1c3d66ad7d2a3c42c97258", "lessThan": "082a6d03a2d685a83a332666b500ad3966349588", "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/38387ccc0fbe38d14fb4c2ad7ee1d7404e5e59fd"}, {"url": "https://git.kernel.org/stable/c/550fa6b5aabb096554536ac1e3ec96b76cbb35fd"}, {"url": "https://git.kernel.org/stable/c/082a6d03a2d685a83a332666b500ad3966349588"}], "title": "slub: fix data loss and overflow in krealloc()", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["mm/slub.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "38387ccc0fbe38d14fb4c2ad7ee1d7404e5e59fd", "status": "affected", "version": "2cd8231796b5e7133b1c3d66ad7d2a3c42c97258", "versionType": "git"}, {"lessThan": "550fa6b5aabb096554536ac1e3ec96b76cbb35fd", "status": "affected", "version": "2cd8231796b5e7133b1c3d66ad7d2a3c42c97258", "versionType": "git"}, {"lessThan": "082a6d03a2d685a83a332666b500ad3966349588", "status": "affected", "version": "2cd8231796b5e7133b1c3d66ad7d2a3c42c97258", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["mm/slub.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "6.18"}, {"lessThan": "6.18", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.27", "versionType": "semver"}, {"lessThanOrEqual": "7.0.*", "status": "unaffected", "version": "7.0.4", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.1", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "1A10DA86-4154-4102-9D63-807CF10A4352", "versionEndExcluding": "6.18.27", "versionStartIncluding": "6.18", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "CDB78D6D-22C3-4154-B0D0-94AF1CE5C2E3", "versionEndExcluding": "7.0.4", "versionStartIncluding": "6.19", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nslub: fix data loss and overflow in krealloc()\n\nCommit 2cd8231796b5 (\"mm/slub: allow to set node and align in\nk[v]realloc\") introduced the ability to force a reallocation if the\noriginal object does not satisfy new alignment or NUMA node, even when\nthe object is being shrunk.\n\nThis introduced two bugs in the reallocation fallback path:\n\n1. Data loss during NUMA migration: The jump to 'alloc_new' happens\n before 'ks' and 'orig_size' are initialized. As a result, the\n memcpy() in the 'alloc_new' block would copy 0 bytes into the new\n allocation.\n\n2. Buffer overflow during shrinking: When shrinking an object while\n forcing a new alignment, 'new_size' is smaller than the old size.\n However, the memcpy() used the old size ('orig_size ?: ks'), leading\n to an out-of-bounds write.\n\nThe same overflow bug exists in the kvrealloc() fallback path, where the\nold bucket size ksize(p) is copied into the new buffer without being\nbounded by the new size.\n\nA simple reproducer:\n\n\t// e.g. add to lkdtm as KREALLOC_SHRINK_OVERFLOW\n\twhile (1) {\n\t\tvoid *p = kmalloc(128, GFP_KERNEL);\n\t\tp = krealloc_node_align(p, 64, 256, GFP_KERNEL, NUMA_NO_NODE);\n\t\tkfree(p);\n\t}\n\ndemonstrates the issue:\n\n ==================================================================\n BUG: KFENCE: out-of-bounds write in memcpy_orig+0x68/0x130\n\n Out-of-bounds write at 0xffff8883ad757038 (120B right of kfence-#47):\n memcpy_orig+0x68/0x130\n krealloc_node_align_noprof+0x1c8/0x340\n lkdtm_KREALLOC_SHRINK_OVERFLOW+0x8c/0xc0 [lkdtm]\n lkdtm_do_action+0x3a/0x60 [lkdtm]\n ...\n\n kfence-#47: 0xffff8883ad756fc0-0xffff8883ad756fff, size=64, cache=kmalloc-64\n\n allocated by task 316 on cpu 7 at 97.680481s (0.021813s ago):\n krealloc_node_align_noprof+0x19c/0x340\n lkdtm_KREALLOC_SHRINK_OVERFLOW+0x8c/0xc0 [lkdtm]\n lkdtm_do_action+0x3a/0x60 [lkdtm]\n ...\n ==================================================================\n\nFix it by moving the old size calculation to the top of __do_krealloc()\nand bounding all copy lengths by the new allocation size."}], "id": "CVE-2026-45990", "lastModified": "2026-06-17T10:52:51.603", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 5.5, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 3.6, "source": "nvd@nist.gov", "type": "Primary"}]}, "published": "2026-05-27T14:17:16.527", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/082a6d03a2d685a83a332666b500ad3966349588"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/38387ccc0fbe38d14fb4c2ad7ee1d7404e5e59fd"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/550fa6b5aabb096554536ac1e3ec96b76cbb35fd"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-190"}], "source": "nvd@nist.gov", "type": "Primary"}]}

{"bugzilla": {"description": "kernel: slub: fix data loss and overflow in krealloc()", "id": "2481962", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2481962"}, "csaw": false, "cwe": "CWE-787", "details": ["A flaw was found in the Linux kernel. This vulnerability, a type of memory corruption, occurs within the krealloc() and kvrealloc() memory reallocation functions. When memory objects are resized or moved, these functions can incorrectly calculate the amount of data to copy, leading to an out-of-bounds write. This could allow a local attacker to cause system instability or potentially execute arbitrary code with elevated privileges."], "name": "CVE-2026-45990", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2026-05-27T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-45990\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-45990\nhttps://lore.kernel.org/linux-cve-announce/2026052739-CVE-2026-45990-09a7@gregkh/T"]}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[2cd8231796b5e7133b1c3d66ad7d2a3c42c97258,38387ccc0fbe38d14fb4c2ad7ee1d7404e5e59fd)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[2cd8231796b5e7133b1c3d66ad7d2a3c42c97258,550fa6b5aabb096554536ac1e3ec96b76cbb35fd)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[2cd8231796b5e7133b1c3d66ad7d2a3c42c97258,082a6d03a2d685a83a332666b500ad3966349588)"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "6.18"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[0,6.18)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.18.27,6.19.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.0.4,7.1.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.1-rc1,*]"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}], "created": "2026-05-27T17:15:38.211857+00:00", "updated": "2026-06-18T00:00:05.841502+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}