# CVE-2023-52833: Bluetooth: btusb: Add date->evt_skb is NULL check

> A local attacker can trigger a kernel crash in the Linux Bluetooth driver by causing a null pointer dereference during device shutdown.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 21 May 2024
- **Updated:** 11 May 2026
- **Also known as:** BELL-CVE-2023-52833, DEBIAN-CVE-2023-52833, GHSA-8crr-8542-6rh6, UBUNTU-CVE-2023-52833

## What is CVE-2023-52833?

CVE-2023-52833 is a medium-severity vulnerability in Linux kernel, published on 21 May 2024. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

Bluetooth: btusb: Add date->evt_skb is NULL check

fix crash because of null pointers

[ 6104.969662] BUG: kernel NULL pointer dereference, address: 00000000000000c8
[ 6104.969667] #PF: supervisor read access in kernel mode
[ 6104.969668] #PF: error_code(0x0000) - not-present page
[ 6104.969670] PGD 0 P4D 0
[ 6104.969673] Oops: 0000 [#1] SMP NOPTI
[ 6104.969684] RIP: 0010:btusb_mtk_hci_wmt_sync+0x144/0x220 [btusb]
[ 6104.969688] RSP: 0018:ffffb8d681533d48 EFLAGS: 00010246
[ 6104.969689] RAX: 0000000000000000 RBX: ffff8ad560bb2000 RCX: 0000000000000006
[ 6104.969691] RDX: 0000000000000000 RSI: ffffb8d681533d08 RDI: 0000000000000000
[ 6104.969692] RBP: ffffb8d681533d70 R08: 0000000000000001 R09: 0000000000000001
[ 6104.969694] R10: 0000000000000001 R11: 00000000fa83b2da R12: ffff8ad461d1d7c0
[ 6104.969695] R13: 0000000000000000 R14: ffff8ad459618c18 R15: ffffb8d681533d90
[ 6104.969697] FS:  00007f5a1cab9d40(0000) GS:ffff8ad578200000(0000) knlGS:00000
[ 6104.969699] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 6104.969700] CR2: 00000000000000c8 CR3: 000000018620c001 CR4: 0000000000760ef0
[ 6104.969701] PKRU: 55555554
[ 6104.969702] Call Trace:
[ 6104.969708]  btusb_mtk_shutdown+0x44/0x80 [btusb]
[ 6104.969732]  hci_dev_do_close+0x470/0x5c0 [bluetooth]
[ 6104.969748]  hci_rfkill_set_block+0x56/0xa0 [bluetooth]
[ 6104.969753]  rfkill_set_block+0x92/0x160
[ 6104.969755]  rfkill_fop_write+0x136/0x1e0
[ 6104.969759]  __vfs_write+0x18/0x40
[ 6104.969761]  vfs_write+0xdf/0x1c0
[ 6104.969763]  ksys_write+0xb1/0xe0
[ 6104.969765]  __x64_sys_write+0x1a/0x20
[ 6104.969769]  do_syscall_64+0x51/0x180
[ 6104.969771]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 6104.969773] RIP: 0033:0x7f5a21f18fef
[ 6104.9] RSP: 002b:00007ffeefe39010 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
[ 6104.969780] RAX: ffffffffffffffda RBX: 000055c10a7560a0 RCX: 00007f5a21f18fef
[ 6104.969781] RDX: 0000000000000008 RSI: 00007ffeefe39060 RDI: 0000000000000012
[ 6104.969782] RBP: 00007ffeefe39060 R08: 0000000000000000 R09: 0000000000000017
[ 6104.969784] R10: 00007ffeefe38d97 R11: 0000000000000293 R12: 0000000000000002
[ 6104.969785] R13: 00007ffeefe39220 R14: 00007ffeefe391a0 R15: 000055c10a72acf0

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2023-52833?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2023-52833?

Apply the vendor's patch.

## Is CVE-2023-52833 being exploited?

There is no known exploitation of CVE-2023-52833 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-52833 and fix it if it is affected.

What it is: CVE-2023-52833 is a medium-severity vulnerability in Linux kernel, published on 21 May 2024. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2023-52833 in the wild and no public exploit code.

Affected product: Linux kernel. 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-2023-52833/ (Markdown: https://insights.sbomify.com/CVE-2023-52833/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-52833
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-52833
- OSV: https://osv.dev/vulnerability/CVE-2023-52833

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-52833/
Summaries are generated and may contain mistakes; the official description above is the record.