GHSA-C2HJ-4VHC-JH3M
Vulnerability from github – Published: 2026-08-15 06:32 – Updated: 2026-08-17 06:33In the Linux kernel, the following vulnerability has been resolved:
ocfs2: validate fast symlink target during inode read
ocfs2_validate_inode_block() already rejects several inconsistent self-contained dinodes before they are exposed to the rest of the filesystem. Fast symlinks need the same treatment.
A zero-cluster symlink is treated as a fast symlink and later read through page_get_link() and ocfs2_fast_symlink_read_folio(). That path uses strnlen() on the inline payload and then copies len + 1 bytes into the folio. If a corrupt dinode stores an i_size that does not fit the inline area or omits the terminating NUL at i_size, that copy reads past the end of the inode block buffer.
Reject zero-cluster symlink dinodes whose i_size exceeds the inline fast-symlink capacity or whose inline payload is not NUL-terminated exactly at i_size when the inode block is validated. This keeps malformed fast symlinks from reaching the read path.
Validation reproduced this kernel report: KASAN use-after-free in ocfs2_fast_symlink_read_folio+0x12c/0x1f0 RIP: 0033:0x7f5c6d859aa7 Read of size 3905 Call trace: dump_stack_lvl+0x66/0xa0 (?:?) print_report+0xce/0x630 (?:?) ocfs2_fast_symlink_read_folio+0x12c/0x1f0 (fs/ocfs2/inode.c:?) srso_alias_return_thunk+0x5/0xfbef5 (?:?) __virt_addr_valid+0x19f/0x330 (?:?) kasan_report+0xe0/0x110 (?:?) kasan_check_range+0x105/0x1b0 (?:?) __asan_memcpy+0x23/0x60 (?:?) filemap_read_folio+0x27/0xe0 (?:?) filemap_read_folio+0x35/0xe0 (?:?) do_read_cache_folio+0x138/0x230 (?:?) __page_get_link+0x26/0x110 (?:?) page_get_link+0x2e/0x70 (?:?) vfs_readlink+0x15e/0x250 (?:?) touch_atime+0x4d/0x370 (?:?) do_readlinkat+0x186/0x200 (?:?) do_user_addr_fault+0x65a/0x890 (?:?) __x64_sys_readlink+0x46/0x60 (?:?) do_syscall_64+0x115/0x6a0 (arch/x86/entry/syscall_64.c:87) entry_SYSCALL_64_after_hwframe+0x77/0x7f (?:?)
{
"affected": [],
"aliases": [
"CVE-2026-74350"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-08-15T06:22:36Z",
"severity": "CRITICAL"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nocfs2: validate fast symlink target during inode read\n\nocfs2_validate_inode_block() already rejects several inconsistent\nself-contained dinodes before they are exposed to the rest of the\nfilesystem. Fast symlinks need the same treatment.\n\nA zero-cluster symlink is treated as a fast symlink and later read through\npage_get_link() and ocfs2_fast_symlink_read_folio(). That path uses\nstrnlen() on the inline payload and then copies len + 1 bytes into the\nfolio. If a corrupt dinode stores an i_size that does not fit the inline\narea or omits the terminating NUL at i_size, that copy reads past the end\nof the inode block buffer.\n\nReject zero-cluster symlink dinodes whose i_size exceeds the inline\nfast-symlink capacity or whose inline payload is not NUL-terminated\nexactly at i_size when the inode block is validated. This keeps malformed\nfast symlinks from reaching the read path.\n\nValidation reproduced this kernel report:\nKASAN use-after-free in ocfs2_fast_symlink_read_folio+0x12c/0x1f0\nRIP: 0033:0x7f5c6d859aa7\nRead of size 3905\nCall trace:\n dump_stack_lvl+0x66/0xa0 (?:?)\n print_report+0xce/0x630 (?:?)\n ocfs2_fast_symlink_read_folio+0x12c/0x1f0 (fs/ocfs2/inode.c:?)\n srso_alias_return_thunk+0x5/0xfbef5 (?:?)\n __virt_addr_valid+0x19f/0x330 (?:?)\n kasan_report+0xe0/0x110 (?:?)\n kasan_check_range+0x105/0x1b0 (?:?)\n __asan_memcpy+0x23/0x60 (?:?)\n filemap_read_folio+0x27/0xe0 (?:?)\n filemap_read_folio+0x35/0xe0 (?:?)\n do_read_cache_folio+0x138/0x230 (?:?)\n __page_get_link+0x26/0x110 (?:?)\n page_get_link+0x2e/0x70 (?:?)\n vfs_readlink+0x15e/0x250 (?:?)\n touch_atime+0x4d/0x370 (?:?)\n do_readlinkat+0x186/0x200 (?:?)\n do_user_addr_fault+0x65a/0x890 (?:?)\n __x64_sys_readlink+0x46/0x60 (?:?)\n do_syscall_64+0x115/0x6a0 (arch/x86/entry/syscall_64.c:87)\n entry_SYSCALL_64_after_hwframe+0x77/0x7f (?:?)",
"id": "GHSA-c2hj-4vhc-jh3m",
"modified": "2026-08-17T06:33:40Z",
"published": "2026-08-15T06:32:30Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-74350"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/e234973f286ed2e8961a24561ec91594ec3e3ff8"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/f9e2cb692b77a679b1f4cc2b7b277fa908586533"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"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.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.