CVE-2026-72369 (GCVE-0-2026-72369)
Vulnerability from cvelistv5
Published
2026-08-15 05:56
Modified
2026-08-17 05:43
Severity ?
VLAI Severity ?
EPSS score ?
Summary
In the Linux kernel, the following vulnerability has been resolved:
minix: avoid overflow in bitmap block count calculation
minix_check_superblock() uses minix_blocks_needed() to verify that the
on-disk imap and zmap block counts are large enough for the advertised
inode and zone counts.
The helper currently performs DIV_ROUND_UP() in unsigned int arithmetic.
A Minix v3 image can set s_ninodes or s_zones near UINT_MAX so the
addition inside DIV_ROUND_UP() wraps to zero. That makes a zero imap/zmap
block count look valid, after which minix_fill_super() can dereference
s_imap[0] or s_zmap[0] even though no bitmap buffers were allocated.
Impact: mounting a crafted Minix v3 image whose s_ninodes or s_zones is
near UINT_MAX makes minix_check_superblock() accept a zero bitmap-block
count and minix_fill_super() dereference s_imap[0]/s_zmap[0], panicking
the kernel.
The divisor is the bitmap capacity in bits, blocksize * 8, which is
always a power of two: minix_fill_super() obtains the block size through
sb_set_blocksize(), and blk_validate_block_size() rejects any size that
is not a power of two. Use DIV_ROUND_UP_POW2(), which divides before
adding the round-up term and so cannot overflow for a power-of-two
divisor.
References
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Linux | Linux |
Version: 2bb588cede1c1969e49c0a2822c8cb8b346b7682 Version: f57ccd4657c7f082dc47e5b9e18a883bb5f9118f Version: 31fefc18096cdc5549cfa54964d90e0b3229aedc Version: 8c97a6ddc95690a938ded44b4e3202f03f15078c Version: 8c97a6ddc95690a938ded44b4e3202f03f15078c Version: a051ecf5c5b0387840dc210413ed3bc7fbdaa69c Version: d791c544efd6b9c944b43cf7f502e5bcb02fb941 Version: 66c7c239c65341f99ae388d4d53dc9df2bcb9925 Version: 1efc128ee4adbc23e082715425ff895449d233bc Version: 6.6.128 ≤ Version: 6.12.75 ≤ Version: 6.18.16 ≤ Version: 5.10.252 ≤ Version: 5.15.202 ≤ Version: 6.1.165 ≤ Version: 6.19.6 ≤ |
||
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"fs/minix/minix.h"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
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"status": "affected",
"version": "2bb588cede1c1969e49c0a2822c8cb8b346b7682",
"versionType": "git"
},
{
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"status": "affected",
"version": "f57ccd4657c7f082dc47e5b9e18a883bb5f9118f",
"versionType": "git"
},
{
"lessThan": "abe3536a4bedcc43de80b6d4d7e3d57e9ba382a5",
"status": "affected",
"version": "31fefc18096cdc5549cfa54964d90e0b3229aedc",
"versionType": "git"
},
{
"lessThan": "8a29e60e2176b02e04f8737c8b32b696230eb0c5",
"status": "affected",
"version": "8c97a6ddc95690a938ded44b4e3202f03f15078c",
"versionType": "git"
},
{
"lessThan": "fb3e566cafc38fe3ba35e6843a2d529a3748870c",
"status": "affected",
"version": "8c97a6ddc95690a938ded44b4e3202f03f15078c",
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{
"status": "affected",
"version": "a051ecf5c5b0387840dc210413ed3bc7fbdaa69c",
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{
"status": "affected",
"version": "d791c544efd6b9c944b43cf7f502e5bcb02fb941",
"versionType": "git"
},
{
"status": "affected",
"version": "66c7c239c65341f99ae388d4d53dc9df2bcb9925",
"versionType": "git"
},
{
"status": "affected",
"version": "1efc128ee4adbc23e082715425ff895449d233bc",
"versionType": "git"
},
{
"lessThan": "6.6.145",
"status": "affected",
"version": "6.6.128",
"versionType": "semver"
},
{
"lessThan": "6.12.97",
"status": "affected",
"version": "6.12.75",
"versionType": "semver"
},
{
"lessThan": "6.18.40",
"status": "affected",
"version": "6.18.16",
"versionType": "semver"
},
{
"lessThan": "5.11",
"status": "affected",
"version": "5.10.252",
"versionType": "semver"
},
{
"lessThan": "5.16",
"status": "affected",
"version": "5.15.202",
"versionType": "semver"
},
{
"lessThan": "6.2",
"status": "affected",
"version": "6.1.165",
"versionType": "semver"
},
{
"lessThan": "6.20",
"status": "affected",
"version": "6.19.6",
"versionType": "semver"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"fs/minix/minix.h"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "7.0"
},
{
"lessThan": "7.0",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.145",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.97",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.40",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.5",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.6.145",
"versionStartIncluding": "6.6.128",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.12.97",
"versionStartIncluding": "6.12.75",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.18.40",
"versionStartIncluding": "6.18.16",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.1.5",
"versionStartIncluding": "7.0",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.2",
"versionStartIncluding": "7.0",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "5.10.252",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "5.15.202",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "6.1.165",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "6.19.6",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nminix: avoid overflow in bitmap block count calculation\n\nminix_check_superblock() uses minix_blocks_needed() to verify that the\non-disk imap and zmap block counts are large enough for the advertised\ninode and zone counts.\n\nThe helper currently performs DIV_ROUND_UP() in unsigned int arithmetic.\nA Minix v3 image can set s_ninodes or s_zones near UINT_MAX so the\naddition inside DIV_ROUND_UP() wraps to zero. That makes a zero imap/zmap\nblock count look valid, after which minix_fill_super() can dereference\ns_imap[0] or s_zmap[0] even though no bitmap buffers were allocated.\n\nImpact: mounting a crafted Minix v3 image whose s_ninodes or s_zones is\nnear UINT_MAX makes minix_check_superblock() accept a zero bitmap-block\ncount and minix_fill_super() dereference s_imap[0]/s_zmap[0], panicking\nthe kernel.\n\nThe divisor is the bitmap capacity in bits, blocksize * 8, which is\nalways a power of two: minix_fill_super() obtains the block size through\nsb_set_blocksize(), and blk_validate_block_size() rejects any size that\nis not a power of two. Use DIV_ROUND_UP_POW2(), which divides before\nadding the round-up term and so cannot overflow for a power-of-two\ndivisor."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 7.8,
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"scenarios": [
{
"lang": "en",
"value": "AV:L - The bug is reached only when the kernel parses a crafted Minix V3 on-disk superblock during block-device mount (mount(2)/fsopen+fsmount \u2192 get_tree_bdev \u2192 minix_fill_super); Minix is not exposed via ksmbd, nfsd, or any network protocol handler.\nAC:L - A Minix V3 image with s_ninodes or s_zones near UINT_MAX and zero/small imap/zmap block counts deterministically makes minix_blocks_needed() wrap to zero, bypassing minix_check_superblock() every time without races or attacker-uncontrollable heap layout.\nPR:L - may_mount() requires CAP_SYS_ADMIN in the mount namespace, which unprivileged attackers obtain inside user namespaces; syzbot reproduced this via fuzzed mounts, and a loop-backed image supplies the required block device without init-namespace root.\nUI:N - No victim action is needed when the attacker with mount capability (e.g., CAP_SYS_ADMIN in a user/mount namespace) mounts their own malicious Minix v3 loop image; exploitation does not depend on tricking another user to open a file or insert removable media.\nS:U - The flaw corrupts or crashes kernel memory during superblock initialization in the mounting context only; it does not cross VM, container, or IOMMU boundaries and matches standard in-kernel memory-corruption/DoS impact (Scope Unchanged).\nC:H - With imap_blocks=1 and overflow-bypassed zmap_blocks=0, s_zmap=\u0026map[1] performs an out-of-bounds heap read of a buffer_head pointer past the under-allocated map; s_imap[0]/s_zmap[0] dereferences on zero-block images also read uninitialized/garbage pointers before panic.\nI:H - After the overflow bypass, minix_set_bit(0,sbi-\u003es_zmap[0]-\u003eb_data) uses the OOB-read pointer and can set a bit at an attacker-influenced kernel address; this is exploitable memory corruption during mount, not a guaranteed-safe NULL-only crash.\nA:H - minix_fill_super() dereferences unallocated s_imap[0]/s_zmap[0] entries and faults the kernel (oops/panic); even the one-bit write via corrupted pointers can immediately fault, causing total loss of kernel availability on the affected system."
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-08-17T05:43:23.188Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/a11ebaab50d27d6c4c78506f84ff36452e0b901d"
},
{
"url": "https://git.kernel.org/stable/c/959c95340a9e19cd333b4c18935fdeecbb2f319d"
},
{
"url": "https://git.kernel.org/stable/c/abe3536a4bedcc43de80b6d4d7e3d57e9ba382a5"
},
{
"url": "https://git.kernel.org/stable/c/8a29e60e2176b02e04f8737c8b32b696230eb0c5"
},
{
"url": "https://git.kernel.org/stable/c/fb3e566cafc38fe3ba35e6843a2d529a3748870c"
}
],
"title": "minix: avoid overflow in bitmap block count calculation",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-72369",
"datePublished": "2026-08-15T05:56:05.995Z",
"dateReserved": "2026-08-09T03:40:39.922Z",
"dateUpdated": "2026-08-17T05:43:23.188Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
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Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.
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