214 lines
13 KiB
JSON
214 lines
13 KiB
JSON
{
|
|
"dataType": "CVE_RECORD",
|
|
"dataVersion": "5.2",
|
|
"cveMetadata": {
|
|
"cveId": "CVE-2026-72175",
|
|
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
|
|
"state": "PUBLISHED",
|
|
"assignerShortName": "Linux",
|
|
"dateReserved": "2026-08-09T03:40:39.910Z",
|
|
"datePublished": "2026-08-15T05:53:40.011Z",
|
|
"dateUpdated": "2026-10-16T18:45:00.474Z"
|
|
},
|
|
"containers": {
|
|
"cna": {
|
|
"providerMetadata": {
|
|
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
|
|
"shortName": "Linux",
|
|
"dateUpdated": "2026-08-17T05:41:11.530Z"
|
|
},
|
|
"descriptions": [
|
|
{
|
|
"lang": "en",
|
|
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nfs/proc/task_mmu: fix make_uffd_wp_huge_pte() prot-update race\n\nPatch series \"userfaultfd/pagemap: pre-existing fixes\".\n\nThese are pre-existing bug fixes that were carried at the front of the\nuserfaultfd RWP working-set-tracking series up to v5 [1]. Per review\nfeedback that fixes should not sit in the middle of a feature series, they\nare split out and sent on their own; the RWP series is reposted rebased on\ntop of this.\n\nAll six were flagged by the Sashiko AI review of the RWP series and carry\nindependent of RWP, apply to mm-new directly, and carry Cc: stable@.\n\n 1: fs/proc/task_mmu: a missing huge_ptep_modify_prot_start() in\n make_uffd_wp_huge_pte() can lose hardware Dirty/Accessed updates\n when PAGEMAP_SCAN write-protects a hugetlb PTE.\n\n 2: fs/proc/task_mmu: pagemap_scan_hugetlb_entry() compares the range\n against HPAGE_SIZE rather than the hstate page size, so it never\n write-protects gigantic hugetlb pages.\n\n 3: fs/proc/task_mmu: PAGEMAP_SCAN with PM_SCAN_WP_MATCHING over an\n unpopulated hugetlb range self-deadlocks -- pagemap_scan_pte_hole()\n calls uffd_wp_range() while walk_hugetlb_range() holds the hugetlb\n vma lock for read, and hugetlb_change_protection() then takes it\n for write. Install the marker inline instead.\n\n 4: mm/huge_memory: change_non_present_huge_pmd() drops pmd_swp_uffd_wp\n on a device-private PMD permission downgrade, silently losing the\n uffd-wp marker.\n\n 5: userfaultfd: must_wait() applies pte_write() to a locklessly read\n PTE without checking pte_present(), so swap/migration entries\n decode random offset bits and a thread can stay parked on a stale\n fault.\n\n 6: userfaultfd: __VMA_UFFD_FLAGS feeds VMA_UFFD_MINOR_BIT (41) to\n mk_vma_flags() unconditionally, an out-of-bounds write into the\n single-word vma_flags_t on 32-bit. Build the mask from config-gated\n per-mode masks so an unavailable bit is never materialised.\n\n\nThis patch (of 6):\n\nmake_uffd_wp_huge_pte() arms the UFFD_WP bit on a present HugeTLB PTE by\ncalling huge_ptep_modify_prot_commit() with a ptent snapshot that was\nfetched without the corresponding huge_ptep_modify_prot_start(). The\nstart helper is what atomically clears the entry so the kernel-owned\nsnapshot stays consistent until the commit; without it, the hardware may\nset Dirty or Accessed in the live PTE between the original read and the\ncommit, and huge_ptep_modify_prot_commit() (whose generic implementation\njust calls set_huge_pte_at()) then writes the stale snapshot back over the\nlive hardware bits, losing the update.\n\nThe non-hugetlb sibling make_uffd_wp_pte() does this correctly via\nptep_modify_prot_start() / ptep_modify_prot_commit(). Mirror that pattern\nfor the present-PTE branch. The migration case stays as-is -- migration\nentries are non-present, so there's no hardware update to race against."
|
|
}
|
|
],
|
|
"metrics": [
|
|
{
|
|
"cvssV3_1": {
|
|
"version": "3.1",
|
|
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N",
|
|
"baseScore": 7.1,
|
|
"baseSeverity": "HIGH"
|
|
},
|
|
"scenarios": [
|
|
{
|
|
"lang": "en",
|
|
"value": "AV:L - The bug is reached only through the PAGEMAP_SCAN ioctl on /proc/<pid>/pagemap, which requires local access to a process address space and cannot be triggered remotely.\nAC:L - The attacker controls both sides of the race by issuing PAGEMAP_SCAN with PM_SCAN_WP_MATCHING while concurrently writing the same present HugeTLB page from another thread in the target process.\nPR:L - Any unprivileged local user can open /proc/self/pagemap and trigger the ioctl; ptrace read checks also allow same-UID access to another process's pagemap without real root privileges.\nUI:N - No victim user action is required; exploitation is performed entirely by the attacker ioctl-ing pagemap and racing writes against their own or same-UID process mappings.\nS:U - The vulnerability corrupts PTE metadata within the target mm only and does not cross VM, container, or kernel/user security boundaries.\nC:H - Stale HugeTLB PTE commits can clear hardware Dirty/Accessed bits; this PTE corruption can expose stale file-backed data to other mappers or userfaultfd migration consumers instead of current memory contents.\nI:H - Lost Dirty bits break folio dirty tracking and writeback for HugeTLB mappings, allowing silent loss or corruption of in-memory modifications that should have been persisted or migrated.\nA:N - The race corrupts PTE metadata without causing kernel oops, panic, or hang; availability impact is limited to incorrect page state rather than system crash."
|
|
}
|
|
]
|
|
}
|
|
],
|
|
"affected": [
|
|
{
|
|
"product": "Linux",
|
|
"vendor": "Linux",
|
|
"defaultStatus": "unaffected",
|
|
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
|
|
"programFiles": [
|
|
"fs/proc/task_mmu.c"
|
|
],
|
|
"versions": [
|
|
{
|
|
"version": "52526ca7fdb905a768a93f8faa418e9b988fc34b",
|
|
"lessThan": "50a25249a6355db74c2c1b6be541b4caab9f3655",
|
|
"status": "affected",
|
|
"versionType": "git"
|
|
},
|
|
{
|
|
"version": "52526ca7fdb905a768a93f8faa418e9b988fc34b",
|
|
"lessThan": "8e39ed92d7c5c6bfc08dc45153916f49a4e98bab",
|
|
"status": "affected",
|
|
"versionType": "git"
|
|
},
|
|
{
|
|
"version": "52526ca7fdb905a768a93f8faa418e9b988fc34b",
|
|
"lessThan": "6b7f774b8882445d9174681747d37c42548686a4",
|
|
"status": "affected",
|
|
"versionType": "git"
|
|
},
|
|
{
|
|
"version": "52526ca7fdb905a768a93f8faa418e9b988fc34b",
|
|
"lessThan": "04718f7c9290f95385f0dd328758753dc1c36dec",
|
|
"status": "affected",
|
|
"versionType": "git"
|
|
}
|
|
]
|
|
},
|
|
{
|
|
"product": "Linux",
|
|
"vendor": "Linux",
|
|
"defaultStatus": "affected",
|
|
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
|
|
"programFiles": [
|
|
"fs/proc/task_mmu.c"
|
|
],
|
|
"versions": [
|
|
{
|
|
"version": "6.7",
|
|
"status": "affected"
|
|
},
|
|
{
|
|
"version": "0",
|
|
"lessThan": "6.7",
|
|
"status": "unaffected",
|
|
"versionType": "semver"
|
|
},
|
|
{
|
|
"version": "6.12.101",
|
|
"lessThanOrEqual": "6.12.*",
|
|
"status": "unaffected",
|
|
"versionType": "semver"
|
|
},
|
|
{
|
|
"version": "6.18.42",
|
|
"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": "6.7",
|
|
"versionEndExcluding": "6.12.101"
|
|
},
|
|
{
|
|
"vulnerable": true,
|
|
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
|
|
"versionStartIncluding": "6.7",
|
|
"versionEndExcluding": "6.18.42"
|
|
},
|
|
{
|
|
"vulnerable": true,
|
|
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
|
|
"versionStartIncluding": "6.7",
|
|
"versionEndExcluding": "7.1.5"
|
|
},
|
|
{
|
|
"vulnerable": true,
|
|
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
|
|
"versionStartIncluding": "6.7",
|
|
"versionEndExcluding": "7.2"
|
|
}
|
|
]
|
|
}
|
|
]
|
|
}
|
|
],
|
|
"references": [
|
|
{
|
|
"url": "https://git.kernel.org/stable/c/50a25249a6355db74c2c1b6be541b4caab9f3655"
|
|
},
|
|
{
|
|
"url": "https://git.kernel.org/stable/c/8e39ed92d7c5c6bfc08dc45153916f49a4e98bab"
|
|
},
|
|
{
|
|
"url": "https://git.kernel.org/stable/c/6b7f774b8882445d9174681747d37c42548686a4"
|
|
},
|
|
{
|
|
"url": "https://git.kernel.org/stable/c/04718f7c9290f95385f0dd328758753dc1c36dec"
|
|
}
|
|
],
|
|
"title": "fs/proc/task_mmu: fix make_uffd_wp_huge_pte() prot-update race",
|
|
"x_generator": {
|
|
"engine": "bippy-1.2.0"
|
|
}
|
|
},
|
|
"adp": [
|
|
{
|
|
"metrics": [
|
|
{
|
|
"other": {
|
|
"type": "ssvc",
|
|
"content": {
|
|
"id": "CVE-2026-72175",
|
|
"role": "CISA Coordinator",
|
|
"options": [
|
|
{
|
|
"Exploitation": "none"
|
|
},
|
|
{
|
|
"Automatable": "no"
|
|
},
|
|
{
|
|
"Technical Impact": "total"
|
|
}
|
|
],
|
|
"version": "2.0.3",
|
|
"timestamp": "2026-10-16T18:43:23.910702Z"
|
|
}
|
|
}
|
|
}
|
|
],
|
|
"title": "CISA ADP Vulnrichment",
|
|
"providerMetadata": {
|
|
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
|
|
"shortName": "CISA-ADP",
|
|
"dateUpdated": "2026-10-16T18:45:00.474Z"
|
|
}
|
|
}
|
|
]
|
|
}
|
|
} |