# CVE-2024-44987: ipv6: prevent UAF in ip6_send_skb()

> A use-after-free vulnerability in the Linux kernel IPv6 stack allows local attackers to potentially execute code or escalate privileges.

- **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:** 4 Sep 2024
- **Updated:** 15 Oct 2026
- **Also known as:** AZL-48627, AZL-48683, BELL-CVE-2024-44987, DEBIAN-CVE-2024-44987, GHSA-wp45-jw6q-jm9q, UBUNTU-CVE-2024-44987

## What is CVE-2024-44987?

CVE-2024-44987 is a high-severity use after free vulnerability in Linux kernel, published on 4 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:

ipv6: prevent UAF in ip6_send_skb()

syzbot reported an UAF in ip6_send_skb() [1]

After ip6_local_out() has returned, we no longer can safely
dereference rt, unless we hold rcu_read_lock().

A similar issue has been fixed in commit
a688caa34beb ("ipv6: take rcu lock in rawv6_send_hdrinc()")

Another potential issue in ip6_finish_output2() is handled in a
separate patch.

[1]
 BUG: KASAN: slab-use-after-free in ip6_send_skb+0x18d/0x230 net/ipv6/ip6_output.c:1964
Read of size 8 at addr ffff88806dde4858 by task syz.1.380/6530

CPU: 1 UID: 0 PID: 6530 Comm: syz.1.380 Not tainted 6.11.0-rc3-syzkaller-00306-gdf6cbc62cc9b #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
Call Trace:
 <TASK>
  __dump_stack lib/dump_stack.c:93 [inline]
  dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119
  print_address_description mm/kasan/report.c:377 [inline]
  print_report+0x169/0x550 mm/kasan/report.c:488
  kasan_report+0x143/0x180 mm/kasan/report.c:601
  ip6_send_skb+0x18d/0x230 net/ipv6/ip6_output.c:1964
  rawv6_push_pending_frames+0x75c/0x9e0 net/ipv6/raw.c:588
  rawv6_sendmsg+0x19c7/0x23c0 net/ipv6/raw.c:926
  sock_sendmsg_nosec net/socket.c:730 [inline]
  __sock_sendmsg+0x1a6/0x270 net/socket.c:745
  sock_write_iter+0x2dd/0x400 net/socket.c:1160
 do_iter_readv_writev+0x60a/0x890
  vfs_writev+0x37c/0xbb0 fs/read_write.c:971
  do_writev+0x1b1/0x350 fs/read_write.c:1018
  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: 0033:0x7f936bf79e79
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f936cd7f038 EFLAGS: 00000246 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 00007f936c115f80 RCX: 00007f936bf79e79
RDX: 0000000000000001 RSI: 0000000020000040 RDI: 0000000000000004
RBP: 00007f936bfe7916 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f936c115f80 R15: 00007fff2860a7a8
 </TASK>

Allocated by task 6530:
  kasan_save_stack mm/kasan/common.c:47 [inline]
  kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
  unpoison_slab_object mm/kasan/common.c:312 [inline]
  __kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:338
  kasan_slab_alloc include/linux/kasan.h:201 [inline]
  slab_post_alloc_hook mm/slub.c:3988 [inline]
  slab_alloc_node mm/slub.c:4037 [inline]
  kmem_cache_alloc_noprof+0x135/0x2a0 mm/slub.c:4044
  dst_alloc+0x12b/0x190 net/core/dst.c:89
  ip6_blackhole_route+0x59/0x340 net/ipv6/route.c:2670
  make_blackhole net/xfrm/xfrm_policy.c:3120 [inline]
  xfrm_lookup_route+0xd1/0x1c0 net/xfrm/xfrm_policy.c:3313
  ip6_dst_lookup_flow+0x13e/0x180 net/ipv6/ip6_output.c:1257
  rawv6_sendmsg+0x1283/0x23c0 net/ipv6/raw.c:898
  sock_sendmsg_nosec net/socket.c:730 [inline]
  __sock_sendmsg+0x1a6/0x270 net/socket.c:745
  ____sys_sendmsg+0x525/0x7d0 net/socket.c:2597
  ___sys_sendmsg net/socket.c:2651 [inline]
  __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2680
  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

Freed by task 45:
  kasan_save_stack mm/kasan/common.c:47 [inline]
  kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
  kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579
  poison_slab_object+0xe0/0x150 mm/kasan/common.c:240
  __kasan_slab_free+0x37/0x60 mm/kasan/common.c:256
  kasan_slab_free include/linux/kasan.h:184 [inline]
  slab_free_hook mm/slub.c:2252 [inline]
  slab_free mm/slub.c:4473 [inline]
  kmem_cache_free+0x145/0x350 mm/slub.c:4548
  dst_destroy+0x2ac/0x460 net/core/dst.c:124
  rcu_do_batch kernel/rcu/tree.c:2569 [inline]
  rcu_core+0xafd/0x1830 kernel/rcu/tree.
---truncated---

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2024-44987?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2024-44987?

Apply the vendor's patch.

## Is CVE-2024-44987 being exploited?

There is no known exploitation of CVE-2024-44987 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-2024-44987 and fix it if it is affected.

What it is: CVE-2024-44987 is a high-severity use after free vulnerability in Linux kernel, published on 4 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-2024-44987 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-2024-44987/ (Markdown: https://insights.sbomify.com/CVE-2024-44987/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-44987
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-44987
- OSV: https://osv.dev/vulnerability/CVE-2024-44987

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-44987/
Summaries are generated and may contain mistakes; the official description above is the record.