GHSA-PHCQ-C45R-9F84
Vulnerability from github – Published: 2026-06-08 18:31 – Updated: 2026-06-14 06:30In the Linux kernel, the following vulnerability has been resolved:
isofs: validate Rock Ridge CE continuation extent against volume size
rock_continue() reads rs->cont_extent verbatim from the Rock Ridge CE record and passes it to sb_bread() without checking that the block number is within the mounted ISO 9660 volume. commit e595447e177b ("[PATCH] rock.c: handle corrupted directories") added cont_offset and cont_size rejection for the CE continuation but did not validate the extent block number itself. commit f54e18f1b831 ("isofs: Fix infinite looping over CE entries") later capped the CE chain length at RR_MAX_CE_ENTRIES = 32 but again left the block number unchecked.
With a crafted ISO mounted via udisks2 (desktop optical auto-mount) or via CAP_SYS_ADMIN mount, rs->cont_extent can therefore point at an out-of-range block or at blocks belonging to an adjacent filesystem on the same block device. sb_bread() on an out-of-range block returns NULL cleanly via the block layer EIO path, so there is no memory-safety violation. For in-range reads of adjacent- filesystem data, the CE buffer is parsed as Rock Ridge records and only the text of SL sub-records reaches userspace through readlink(), which makes the info-leak channel narrow and difficult to exploit; still, rejecting the malformed CE outright matches the rejection shape already present in the same function for cont_offset and cont_size.
Add an ISOFS_SB(sb)->s_nzones bounds check to rock_continue() next to the existing offset/size rejection, printing the same corrupted-directory-entry notice.
{
"affected": [],
"aliases": [
"CVE-2026-46303"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-06-08T17:16:48Z",
"severity": "HIGH"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nisofs: validate Rock Ridge CE continuation extent against volume size\n\nrock_continue() reads rs-\u003econt_extent verbatim from the Rock Ridge CE\nrecord and passes it to sb_bread() without checking that the block\nnumber is within the mounted ISO 9660 volume. commit e595447e177b\n(\"[PATCH] rock.c: handle corrupted directories\") added cont_offset\nand cont_size rejection for the CE continuation but did not validate\nthe extent block number itself. commit f54e18f1b831 (\"isofs: Fix\ninfinite looping over CE entries\") later capped the CE chain length\nat RR_MAX_CE_ENTRIES = 32 but again left the block number unchecked.\n\nWith a crafted ISO mounted via udisks2 (desktop optical auto-mount)\nor via CAP_SYS_ADMIN mount, rs-\u003econt_extent can therefore point at\nan out-of-range block or at blocks belonging to an adjacent\nfilesystem on the same block device. sb_bread() on an out-of-range\nblock returns NULL cleanly via the block layer EIO path, so there\nis no memory-safety violation. For in-range reads of adjacent-\nfilesystem data, the CE buffer is parsed as Rock Ridge records and\nonly the text of SL sub-records reaches userspace through\nreadlink(), which makes the info-leak channel narrow and difficult\nto exploit; still, rejecting the malformed CE outright matches the\nrejection shape already present in the same function for\ncont_offset and cont_size.\n\nAdd an ISOFS_SB(sb)-\u003es_nzones bounds check to rock_continue() next\nto the existing offset/size rejection, printing the same\ncorrupted-directory-entry notice.",
"id": "GHSA-phcq-c45r-9f84",
"modified": "2026-06-14T06:30:23Z",
"published": "2026-06-08T18:31:53Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-46303"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/22b36fa081f38ab397c7697f9d539211b51a0cfc"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/8356fb821016797f5677cbeee5ddc0d32a95b4be"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/a36d990f591320e9dd379ab30063ebfe91d47e1f"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/bf1bc673c587f5ef7e9c09b94aea7c5a7847d4d9"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/c9b37c8b73f6368e4750e5ccb0632c380b43c6e5"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/d582e12378bc1637f337622feef762f53c43fd57"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/e69da8eeab74b4f4505024c38a17bce060fe7df8"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/ef048470c90bc8c1b8318bb2ce329da9ef64b9fe"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N",
"type": "CVSS_V3"
}
]
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.