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

apparmor: avoid crash when parsed profile name is empty

When processing a packed profile in unpack_profile() described like

"profile :ns::samba-dcerpcd /usr/lib*/samba/{,samba/}samba-dcerpcd {...}"

a string ":samba-dcerpcd" is unpacked as a fully-qualified name and then
passed to aa_splitn_fqname().

aa_splitn_fqname() treats ":samba-dcerpcd" as only containing a namespace.
Thus it returns NULL for tmpname, meanwhile tmpns is non-NULL. Later
aa_alloc_profile() crashes as the new profile name is NULL now.

general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 6 PID: 1657 Comm: apparmor_parser Not tainted 6.7.0-rc2-dirty #16
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.2-3-gd478f380-rebuilt.opensuse.org 04/01/2014
RIP: 0010:strlen+0x1e/0xa0
Call Trace:
<TASK>
? strlen+0x1e/0xa0
aa_policy_init+0x1bb/0x230
aa_alloc_profile+0xb1/0x480
unpack_profile+0x3bc/0x4960
aa_unpack+0x309/0x15e0
aa_replace_profiles+0x213/0x33c0
policy_update+0x261/0x370
profile_replace+0x20e/0x2a0
vfs_write+0x2af/0xe00
ksys_write+0x126/0x250
do_syscall_64+0x46/0xf0
entry_SYSCALL_64_after_hwframe+0x6e/0x76
</TASK>
---[ end trace 0000000000000000 ]---
RIP: 0010:strlen+0x1e/0xa0

It seems such behaviour of aa_splitn_fqname() is expected and checked in
other places where it is called (e.g. aa_remove_profiles). Well, there
is an explicit comment "a ns name without a following profile is allowed"
inside.

AFAICS, nothing can prevent unpacked "name" to be in form like
":samba-dcerpcd" - it is passed from userspace.

Deny the whole profile set replacement in such case and inform user with
EPROTO and an explaining message.

Found by Linux Verification Center (linuxtesting.org).
Published: 2024-02-22
Score: 5.5 Medium
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

No analysis available yet.

Remediation

No remediation available yet.

Tracking

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Advisories
Source ID Title
Debian DLA Debian DLA DLA-3840-1 linux security update
Debian DLA Debian DLA DLA-3841-1 linux-5.10 security update
Ubuntu USN Ubuntu USN USN-6688-1 Linux kernel (OEM) vulnerabilities
Ubuntu USN Ubuntu USN USN-6725-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6725-2 Linux kernel (AWS) vulnerabilities
Ubuntu USN Ubuntu USN USN-6726-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6726-2 Linux kernel (IoT) vulnerabilities
Ubuntu USN Ubuntu USN USN-6726-3 Linux kernel (Xilinx ZynqMP) vulnerabilities
Ubuntu USN Ubuntu USN USN-6818-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6818-2 Linux kernel (ARM laptop) vulnerabilities
Ubuntu USN Ubuntu USN USN-6818-3 Linux kernel (NVIDIA) vulnerabilities
Ubuntu USN Ubuntu USN USN-6818-4 Linux kernel (HWE) vulnerabilities
Ubuntu USN Ubuntu USN USN-6819-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6819-2 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6819-3 Linux kernel (OEM) vulnerabilities
Ubuntu USN Ubuntu USN USN-6819-4 Linux kernel (Oracle) vulnerabilities
Ubuntu USN Ubuntu USN USN-6926-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6926-2 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6926-3 Linux kernel (Azure) vulnerabilities
History

Fri, 22 Nov 2024 12:00:00 +0000


Mon, 04 Nov 2024 15:15:00 +0000

Type Values Removed Values Added
References
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Subscriptions

Linux Linux Kernel
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2025-05-04T07:36:39.239Z

Reserved: 2024-02-20T12:30:33.291Z

Link: CVE-2023-52443

cve-icon Vulnrichment

Updated: 2024-08-02T22:55:41.517Z

cve-icon NVD

Status : Modified

Published: 2024-02-22T17:15:08.377

Modified: 2024-11-21T08:39:46.453

Link: CVE-2023-52443

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses