# CVE-2026-74350: ocfs2: validate fast symlink target during inode read

> A use-after-free vulnerability in the Linux kernel OCFS2 filesystem allows attackers to execute code or cause denial of service via crafted fast symlinks.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 15 Aug 2026
- **Updated:** 21 Oct 2026
- **Also known as:** BELL-CVE-2026-74350, DEBIAN-CVE-2026-74350, GHSA-c2hj-4vhc-jh3m, UBUNTU-CVE-2026-74350

## What is CVE-2026-74350?

CVE-2026-74350 is a critical use after free vulnerability in Linux, published on 15 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

In 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 (?:?)

## Which versions are affected by CVE-2026-74350?


## How do I fix CVE-2026-74350?

Apply the vendor's patch.

## Is CVE-2026-74350 being exploited?

There is no known exploitation of CVE-2026-74350 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-74350 and fix it if it is affected.

What it is: CVE-2026-74350 is a critical use after free vulnerability in Linux, published on 15 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-74350 in the wild and no public exploit code.

Affected product: Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-74350/ (Markdown: https://insights.sbomify.com/CVE-2026-74350/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-74350
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-74350
- OSV: https://osv.dev/vulnerability/CVE-2026-74350

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-74350/
Summaries are generated and may contain mistakes; the official description above is the record.