# CVE-2024-47709: can: bcm: Clear bo->bcm_proc_read after remove_proc_entry().

> A use-after-free vulnerability in the Linux kernel CAN BCM module allows local attackers to trigger a kernel warning and potential denial of service.

- **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 Oct 2024
- **Updated:** 15 Oct 2026
- **Also known as:** AZL-51189, BELL-CVE-2024-47709, DEBIAN-CVE-2024-47709, GHSA-x972-pghh-qmrh, UBUNTU-CVE-2024-47709

## What is CVE-2024-47709?

CVE-2024-47709 is a medium-severity use after free vulnerability in Linux kernel, published on 21 Oct 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: Clear bo->bcm_proc_read after remove_proc_entry().

syzbot reported a warning in bcm_release(). [0]

The blamed change fixed another warning that is triggered when
connect() is issued again for a socket whose connect()ed device has
been unregistered.

However, if the socket is just close()d without the 2nd connect(), the
remaining bo->bcm_proc_read triggers unnecessary remove_proc_entry()
in bcm_release().

Let's clear bo->bcm_proc_read after remove_proc_entry() in bcm_notify().

[0]
name '4986'
WARNING: CPU: 0 PID: 5234 at fs/proc/generic.c:711 remove_proc_entry+0x2e7/0x5d0 fs/proc/generic.c:711
Modules linked in:
CPU: 0 UID: 0 PID: 5234 Comm: syz-executor606 Not tainted 6.11.0-rc5-syzkaller-00178-g5517ae241919 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
RIP: 0010:remove_proc_entry+0x2e7/0x5d0 fs/proc/generic.c:711
Code: ff eb 05 e8 cb 1e 5e ff 48 8b 5c 24 10 48 c7 c7 e0 f7 aa 8e e8 2a 38 8e 09 90 48 c7 c7 60 3a 1b 8c 48 89 de e8 da 42 20 ff 90 <0f> 0b 90 90 48 8b 44 24 18 48 c7 44 24 40 0e 36 e0 45 49 c7 04 07
RSP: 0018:ffffc9000345fa20 EFLAGS: 00010246
RAX: 2a2d0aee2eb64600 RBX: ffff888032f1f548 RCX: ffff888029431e00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc9000345fb08 R08: ffffffff8155b2f2 R09: 1ffff1101710519a
R10: dffffc0000000000 R11: ffffed101710519b R12: ffff888011d38640
R13: 0000000000000004 R14: 0000000000000000 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8880b8800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fcfb52722f0 CR3: 000000000e734000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 bcm_release+0x250/0x880 net/can/bcm.c:1578
 __sock_release net/socket.c:659 [inline]
 sock_close+0xbc/0x240 net/socket.c:1421
 __fput+0x24a/0x8a0 fs/file_table.c:422
 task_work_run+0x24f/0x310 kernel/task_work.c:228
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0xa2f/0x27f0 kernel/exit.c:882
 do_group_exit+0x207/0x2c0 kernel/exit.c:1031
 __do_sys_exit_group kernel/exit.c:1042 [inline]
 __se_sys_exit_group kernel/exit.c:1040 [inline]
 __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1040
 x64_sys_call+0x2634/0x2640 arch/x86/include/generated/asm/syscalls_64.h:232
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fcfb51ee969
Code: Unable to access opcode bytes at 0x7fcfb51ee93f.
RSP: 002b:00007ffce0109ca8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007fcfb51ee969
RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000001
RBP: 00007fcfb526f3b0 R08: ffffffffffffffb8 R09: 0000555500000000
R10: 0000555500000000 R11: 0000000000000246 R12: 00007fcfb526f3b0
R13: 0000000000000000 R14: 00007fcfb5271ee0 R15: 00007fcfb51bf160
 </TASK>

## Which versions are affected by CVE-2024-47709?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2024-47709?

Apply the vendor's patch.

## Is CVE-2024-47709 being exploited?

There is no known exploitation of CVE-2024-47709 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-2024-47709 and fix it if it is affected.

What it is: CVE-2024-47709 is a medium-severity use after free vulnerability in Linux kernel, published on 21 Oct 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-2024-47709 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-2024-47709/ (Markdown: https://insights.sbomify.com/CVE-2024-47709/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-47709
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-47709
- OSV: https://osv.dev/vulnerability/CVE-2024-47709

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-47709/
Summaries are generated and may contain mistakes; the official description above is the record.