CVE-2024-47709

/// Technical 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

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References