{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-45837", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-05-13T15:03:33.077Z", "datePublished": "2026-05-27T09:24:32.833Z", "dateUpdated": "2026-05-27T09:24:32.833Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-05-27T09:24:32.833Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix use-after-free in arena_vm_close on fork\n\narena_vm_open() only bumps vml->mmap_count but never registers the\nchild VMA in arena->vma_list. The vml->vma always points at the\nparent VMA, so after parent munmap the pointer dangles. If the child\nthen calls bpf_arena_free_pages(), zap_pages() reads the stale\nvml->vma triggering use-after-free.\n\nFix this by preventing the arena VMA from being inherited across\nfork with VM_DONTCOPY, and preventing VMA splits via the may_split\ncallback.\n\nAlso reject mremap with a .mremap callback returning -EINVAL. A\nsame-size mremap(MREMAP_FIXED) on the full arena VMA reaches\ncopy_vma() through the following path:\n\n check_prep_vma() - returns 0 early: new_len == old_len\n skips VM_DONTEXPAND check\n prep_move_vma() - vm_start == old_addr and\n vm_end == old_addr + old_len\n so may_split is never called\n move_vma()\n copy_vma_and_data()\n copy_vma()\n vm_area_dup() - copies vm_private_data (vml pointer)\n vm_ops->open() - bumps vml->mmap_count\n vm_ops->mremap() - returns -EINVAL, rollback unmaps new VMA\n\nThe refcount ensures the rollback's arena_vm_close does not free\nthe vml shared with the original VMA."}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["kernel/bpf/arena.c"], "versions": [{"version": "317460317a02a1af512697e6e964298dedd8a163", "lessThan": "723b9fa930cc277c15ce6b9ec9feec828cfac9d7", "status": "affected", "versionType": "git"}, {"version": "317460317a02a1af512697e6e964298dedd8a163", "lessThan": "d18099f19e53250f8ad2801498b88cec29d9107a", "status": "affected", "versionType": "git"}, {"version": "317460317a02a1af512697e6e964298dedd8a163", "lessThan": "201128fcc7b213d27ab77bc4e89488b41796480f", "status": "affected", "versionType": "git"}, {"version": "317460317a02a1af512697e6e964298dedd8a163", "lessThan": "4fddde2a732de60bb97e3307d4eb69ac5f1d2b74", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["kernel/bpf/arena.c"], "versions": [{"version": "6.9", "status": "affected"}, {"version": "0", "lessThan": "6.9", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.88", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.30", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.0.7", "lessThanOrEqual": "7.0.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.1-rc1", "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": "6.9", "versionEndExcluding": "6.12.88"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.9", "versionEndExcluding": "6.18.30"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.9", "versionEndExcluding": "7.0.7"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.9", "versionEndExcluding": "7.1-rc1"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/723b9fa930cc277c15ce6b9ec9feec828cfac9d7"}, {"url": "https://git.kernel.org/stable/c/d18099f19e53250f8ad2801498b88cec29d9107a"}, {"url": "https://git.kernel.org/stable/c/201128fcc7b213d27ab77bc4e89488b41796480f"}, {"url": "https://git.kernel.org/stable/c/4fddde2a732de60bb97e3307d4eb69ac5f1d2b74"}], "title": "bpf: Fix use-after-free in arena_vm_close on fork", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix use-after-free in arena_vm_close on fork\n\narena_vm_open() only bumps vml->mmap_count but never registers the\nchild VMA in arena->vma_list. The vml->vma always points at the\nparent VMA, so after parent munmap the pointer dangles. If the child\nthen calls bpf_arena_free_pages(), zap_pages() reads the stale\nvml->vma triggering use-after-free.\n\nFix this by preventing the arena VMA from being inherited across\nfork with VM_DONTCOPY, and preventing VMA splits via the may_split\ncallback.\n\nAlso reject mremap with a .mremap callback returning -EINVAL. A\nsame-size mremap(MREMAP_FIXED) on the full arena VMA reaches\ncopy_vma() through the following path:\n\n check_prep_vma() - returns 0 early: new_len == old_len\n skips VM_DONTEXPAND check\n prep_move_vma() - vm_start == old_addr and\n vm_end == old_addr + old_len\n so may_split is never called\n move_vma()\n copy_vma_and_data()\n copy_vma()\n vm_area_dup() - copies vm_private_data (vml pointer)\n vm_ops->open() - bumps vml->mmap_count\n vm_ops->mremap() - returns -EINVAL, rollback unmaps new VMA\n\nThe refcount ensures the rollback's arena_vm_close does not free\nthe vml shared with the original VMA."}], "id": "CVE-2026-45837", "lastModified": "2026-05-27T11:16:23.020", "metrics": {}, "published": "2026-05-27T11:16:23.020", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/201128fcc7b213d27ab77bc4e89488b41796480f"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/4fddde2a732de60bb97e3307d4eb69ac5f1d2b74"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/723b9fa930cc277c15ce6b9ec9feec828cfac9d7"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/d18099f19e53250f8ad2801498b88cec29d9107a"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{}

{}