# CVE-2024-46721: apparmor: fix possible NULL pointer dereference

> A NULL pointer dereference in the Linux kernel AppArmor module allows local attackers to cause a system crash via crafted profile updates.

- **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:** 18 Sep 2024
- **Updated:** 11 May 2026
- **Also known as:** AZL-49389, BELL-CVE-2024-46721, DEBIAN-CVE-2024-46721, GHSA-3mwh-qccg-vxm7, UBUNTU-CVE-2024-46721

## What is CVE-2024-46721?

CVE-2024-46721 is a medium-severity 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:

apparmor: fix possible NULL pointer dereference

profile->parent->dents[AAFS_PROF_DIR] could be NULL only if its parent is made
from __create_missing_ancestors(..) and 'ent->old' is NULL in
aa_replace_profiles(..).
In that case, it must return an error code and the code, -ENOENT represents
its state that the path of its parent is not existed yet.

BUG: kernel NULL pointer dereference, address: 0000000000000030
PGD 0 P4D 0
PREEMPT SMP PTI
CPU: 4 PID: 3362 Comm: apparmor_parser Not tainted 6.8.0-24-generic #24
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1 04/01/2014
RIP: 0010:aafs_create.constprop.0+0x7f/0x130
Code: 4c 63 e0 48 83 c4 18 4c 89 e0 5b 41 5c 41 5d 41 5e 41 5f 5d 31 d2 31 c9 31 f6 31 ff 45 31 c0 45 31 c9 45 31 d2 c3 cc cc cc cc <4d> 8b 55 30 4d 8d ba a0 00 00 00 4c 89 55 c0 4c 89 ff e8 7a 6a ae
RSP: 0018:ffffc9000b2c7c98 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 00000000000041ed RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc9000b2c7cd8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff82baac10
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS:  00007be9f22cf740(0000) GS:ffff88817bc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000030 CR3: 0000000134b08000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 ? show_regs+0x6d/0x80
 ? __die+0x24/0x80
 ? page_fault_oops+0x99/0x1b0
 ? kernelmode_fixup_or_oops+0xb2/0x140
 ? __bad_area_nosemaphore+0x1a5/0x2c0
 ? find_vma+0x34/0x60
 ? bad_area_nosemaphore+0x16/0x30
 ? do_user_addr_fault+0x2a2/0x6b0
 ? exc_page_fault+0x83/0x1b0
 ? asm_exc_page_fault+0x27/0x30
 ? aafs_create.constprop.0+0x7f/0x130
 ? aafs_create.constprop.0+0x51/0x130
 __aafs_profile_mkdir+0x3d6/0x480
 aa_replace_profiles+0x83f/0x1270
 policy_update+0xe3/0x180
 profile_load+0xbc/0x150
 ? rw_verify_area+0x47/0x140
 vfs_write+0x100/0x480
 ? __x64_sys_openat+0x55/0xa0
 ? syscall_exit_to_user_mode+0x86/0x260
 ksys_write+0x73/0x100
 __x64_sys_write+0x19/0x30
 x64_sys_call+0x7e/0x25c0
 do_syscall_64+0x7f/0x180
 entry_SYSCALL_64_after_hwframe+0x78/0x80
RIP: 0033:0x7be9f211c574
Code: c7 00 16 00 00 00 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 80 3d d5 ea 0e 00 00 74 13 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 c3 0f 1f 00 55 48 89 e5 48 83 ec 20 48 89
RSP: 002b:00007ffd26f2b8c8 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00005d504415e200 RCX: 00007be9f211c574
RDX: 0000000000001fc1 RSI: 00005d504418bc80 RDI: 0000000000000004
RBP: 0000000000001fc1 R08: 0000000000001fc1 R09: 0000000080000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00005d504418bc80
R13: 0000000000000004 R14: 00007ffd26f2b9b0 R15: 00007ffd26f2ba30
 </TASK>
Modules linked in: snd_seq_dummy snd_hrtimer qrtr snd_hda_codec_generic snd_hda_intel snd_intel_dspcfg snd_intel_sdw_acpi snd_hda_codec snd_hda_core snd_hwdep snd_pcm snd_seq_midi snd_seq_midi_event snd_rawmidi snd_seq snd_seq_device i2c_i801 snd_timer i2c_smbus qxl snd soundcore drm_ttm_helper lpc_ich ttm joydev input_leds serio_raw mac_hid binfmt_misc msr parport_pc ppdev lp parport efi_pstore nfnetlink dmi_sysfs qemu_fw_cfg ip_tables x_tables autofs4 hid_generic usbhid hid ahci libahci psmouse virtio_rng xhci_pci xhci_pci_renesas
CR2: 0000000000000030
---[ end trace 0000000000000000 ]---
RIP: 0010:aafs_create.constprop.0+0x7f/0x130
Code: 4c 63 e0 48 83 c4 18 4c 89 e0 5b 41 5c 41 5d 41 5e 41 5f 5d 31 d2 31 c9 31 f6 31 ff 45 31 c0 45 31 c9 45 31 d2 c3 cc cc cc cc <4d> 8b 55 30 4d 8d ba a0 00 00 00 4c 89 55 c0 4c 89 ff e8 7a 6a ae
RSP: 0018:ffffc9000b2c7c98 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 00000000000041ed RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc9000b2c7cd8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000
---truncated---

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2024-46721?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2024-46721?

Apply the vendor's patch.

## Is CVE-2024-46721 being exploited?

There is no known exploitation of CVE-2024-46721 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-2024-46721 and fix it if it is affected.

What it is: CVE-2024-46721 is a medium-severity 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-2024-46721 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-2024-46721/ (Markdown: https://insights.sbomify.com/CVE-2024-46721/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-46721
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-46721
- OSV: https://osv.dev/vulnerability/CVE-2024-46721

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-46721/
Summaries are generated and may contain mistakes; the official description above is the record.