# CVE-2024-46771: can: bcm: Remove proc entry when dev is unregistered.

> A local attacker can trigger a memory leak in the Linux kernel CAN BCM module by racing device unregistration with socket connection, causing a warning and potential resource exhaustion.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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:** 18 Sep 2024
- **Updated:** 5 Aug 2026
- **Also known as:** BELL-CVE-2024-46771, DEBIAN-CVE-2024-46771, GHSA-82f5-7m6p-jqwq, UBUNTU-CVE-2024-46771

## What is CVE-2024-46771?

CVE-2024-46771 is a high-severity memory corruption vulnerability in Linux kernel, published on 18 Sep 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:

can: bcm: Remove proc entry when dev is unregistered.

syzkaller reported a warning in bcm_connect() below. [0]

The repro calls connect() to vxcan1, removes vxcan1, and calls
connect() with ifindex == 0.

Calling connect() for a BCM socket allocates a proc entry.
Then, bcm_sk(sk)->bound is set to 1 to prevent further connect().

However, removing the bound device resets bcm_sk(sk)->bound to 0
in bcm_notify().

The 2nd connect() tries to allocate a proc entry with the same
name and sets NULL to bcm_sk(sk)->bcm_proc_read, leaking the
original proc entry.

Since the proc entry is available only for connect()ed sockets,
let's clean up the entry when the bound netdev is unregistered.

[0]:
proc_dir_entry 'can-bcm/2456' already registered
WARNING: CPU: 1 PID: 394 at fs/proc/generic.c:376 proc_register+0x645/0x8f0 fs/proc/generic.c:375
Modules linked in:
CPU: 1 PID: 394 Comm: syz-executor403 Not tainted 6.10.0-rc7-g852e42cc2dd4
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
RIP: 0010:proc_register+0x645/0x8f0 fs/proc/generic.c:375
Code: 00 00 00 00 00 48 85 ed 0f 85 97 02 00 00 4d 85 f6 0f 85 9f 02 00 00 48 c7 c7 9b cb cf 87 48 89 de 4c 89 fa e8 1c 6f eb fe 90 <0f> 0b 90 90 48 c7 c7 98 37 99 89 e8 cb 7e 22 05 bb 00 00 00 10 48
RSP: 0018:ffa0000000cd7c30 EFLAGS: 00010246
RAX: 9e129be1950f0200 RBX: ff1100011b51582c RCX: ff1100011857cd80
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000002
RBP: 0000000000000000 R08: ffd400000000000f R09: ff1100013e78cac0
R10: ffac800000cd7980 R11: ff1100013e12b1f0 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: ff1100011a99a2ec
FS:  00007fbd7086f740(0000) GS:ff1100013fd00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000200071c0 CR3: 0000000118556004 CR4: 0000000000771ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe07f0 DR7: 0000000000000400
PKRU: 55555554
Call Trace:
 <TASK>
 proc_create_net_single+0x144/0x210 fs/proc/proc_net.c:220
 bcm_connect+0x472/0x840 net/can/bcm.c:1673
 __sys_connect_file net/socket.c:2049 [inline]
 __sys_connect+0x5d2/0x690 net/socket.c:2066
 __do_sys_connect net/socket.c:2076 [inline]
 __se_sys_connect net/socket.c:2073 [inline]
 __x64_sys_connect+0x8f/0x100 net/socket.c:2073
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xd9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x4b/0x53
RIP: 0033:0x7fbd708b0e5d
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 73 9f 1b 00 f7 d8 64 89 01 48
RSP: 002b:00007fff8cd33f08 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007fbd708b0e5d
RDX: 0000000000000010 RSI: 0000000020000040 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000040 R09: 0000000000000040
R10: 0000000000000040 R11: 0000000000000246 R12: 00007fff8cd34098
R13: 0000000000401280 R14: 0000000000406de8 R15: 00007fbd70ab9000
 </TASK>
remove_proc_entry: removing non-empty directory 'net/can-bcm', leaking at least '2456'

## Which versions are affected by CVE-2024-46771?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2024-46771?

Apply the vendor's patch.

## Is CVE-2024-46771 being exploited?

There is no known exploitation of CVE-2024-46771 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-2024-46771 and fix it if it is affected.

What it is: CVE-2024-46771 is a high-severity memory corruption vulnerability in Linux kernel, published on 18 Sep 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-2024-46771 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-2024-46771/ (Markdown: https://insights.sbomify.com/CVE-2024-46771/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-46771
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-46771
- OSV: https://osv.dev/vulnerability/CVE-2024-46771

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-46771/
Summaries are generated and may contain mistakes; the official description above is the record.