# CVE-2024-36916: blk-iocost: avoid out of bounds shift

> An out-of-bounds shift in the Linux kernel's blk-iocost module can cause undefined behavior, potentially leading to system instability or crashes.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 30 May 2024
- **Updated:** 15 Oct 2026
- **Also known as:** BELL-CVE-2024-36916, DEBIAN-CVE-2024-36916, UBUNTU-CVE-2024-36916

## What is CVE-2024-36916?

CVE-2024-36916 is a medium-severity vulnerability in Debian Debian Linux, published on 30 May 2024. 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:

blk-iocost: avoid out of bounds shift

UBSAN catches undefined behavior in blk-iocost, where sometimes
iocg->delay is shifted right by a number that is too large,
resulting in undefined behavior on some architectures.

[  186.556576] ------------[ cut here ]------------
UBSAN: shift-out-of-bounds in block/blk-iocost.c:1366:23
shift exponent 64 is too large for 64-bit type 'u64' (aka 'unsigned long long')
CPU: 16 PID: 0 Comm: swapper/16 Tainted: G S          E    N 6.9.0-0_fbk700_debug_rc2_kbuilder_0_gc85af715cac0 #1
Hardware name: Quanta Twin Lakes MP/Twin Lakes Passive MP, BIOS F09_3A23 12/08/2020
Call Trace:
 <IRQ>
 dump_stack_lvl+0x8f/0xe0
 __ubsan_handle_shift_out_of_bounds+0x22c/0x280
 iocg_kick_delay+0x30b/0x310
 ioc_timer_fn+0x2fb/0x1f80
 __run_timer_base+0x1b6/0x250
...

Avoid that undefined behavior by simply taking the
"delay = 0" branch if the shift is too large.

I am not sure what the symptoms of an undefined value
delay will be, but I suspect it could be more than a
little annoying to debug.

Weakness: CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2024-36916?

It affects 2 products.


Products: Debian Debian Linux, Linux kernel.

## How do I fix CVE-2024-36916?

Apply the vendor's patch.

## Is CVE-2024-36916 being exploited?

There is no known exploitation of CVE-2024-36916 in the wild and no public exploit code.

## Other vulnerabilities in Debian Debian Linux

- [CVE-2015-3306](https://insights.sbomify.com/CVE-2015-3306/): ProFTPD Improper Access Control (critical 10.0, exploited in the wild)
- [CVE-2025-49113](https://insights.sbomify.com/CVE-2025-49113/): RoundCube Webmail Deserialization of Untrusted Data (critical 9.9, exploited in the wild)
- [CVE-2026-24061](https://insights.sbomify.com/CVE-2026-24061/): GNU InetUtils Argument Injection (critical 9.8, exploited in the wild)
- [CVE-2025-39682](https://insights.sbomify.com/CVE-2025-39682/): Linux Kernel Improper Check for Unusual or Exceptional Conditions (critical 9.8, exploited in the wild)
- [CVE-2024-9680](https://insights.sbomify.com/CVE-2024-9680/): Mozilla Firefox Use-After-Free (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2024-36916 and fix it if it is affected.

What it is: CVE-2024-36916 is a medium-severity vulnerability in Debian Debian Linux, published on 30 May 2024. 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-2024-36916 in the wild and no public exploit code.

Affected product: Debian Debian 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-2024-36916/ (Markdown: https://insights.sbomify.com/CVE-2024-36916/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-36916
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-36916
- OSV: https://osv.dev/vulnerability/CVE-2024-36916

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-36916/
Summaries are generated and may contain mistakes; the official description above is the record.