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

af_unix: Update unix_sk(sk)->oob_skb under sk_receive_queue lock.

Billy Jheng Bing-Jhong reported a race between __unix_gc() and
queue_oob().

__unix_gc() tries to garbage-collect close()d inflight sockets,
and then if the socket has MSG_OOB in unix_sk(sk)->oob_skb, GC
will drop the reference and set NULL to it locklessly.

However, the peer socket still can send MSG_OOB message and
queue_oob() can update unix_sk(sk)->oob_skb concurrently, leading
NULL pointer dereference. [0]

To fix the issue, let's update unix_sk(sk)->oob_skb under the
sk_receive_queue's lock and take it everywhere we touch oob_skb.

Note that we defer kfree_skb() in manage_oob() to silence lockdep
false-positive (See [1]).

[0]:
BUG: kernel NULL pointer dereference, address: 0000000000000008
PF: supervisor write access in kernel mode
PF: error_code(0x0002) - not-present page
PGD 8000000009f5e067 P4D 8000000009f5e067 PUD 9f5d067 PMD 0
Oops: 0002 [#1] PREEMPT SMP PTI
CPU: 3 PID: 50 Comm: kworker/3:1 Not tainted 6.9.0-rc5-00191-gd091e579b864 #110
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
Workqueue: events delayed_fput
RIP: 0010:skb_dequeue (./include/linux/skbuff.h:2386 ./include/linux/skbuff.h:2402 net/core/skbuff.c:3847)
Code: 39 e3 74 3e 8b 43 10 48 89 ef 83 e8 01 89 43 10 49 8b 44 24 08 49 c7 44 24 08 00 00 00 00 49 8b 14 24 49 c7 04 24 00 00 00 00 <48> 89 42 08 48 89 10 e8 e7 c5 42 00 4c 89 e0 5b 5d 41 5c c3 cc cc
RSP: 0018:ffffc900001bfd48 EFLAGS: 00000002
RAX: 0000000000000000 RBX: ffff8880088f5ae8 RCX: 00000000361289f9
RDX: 0000000000000000 RSI: 0000000000000206 RDI: ffff8880088f5b00
RBP: ffff8880088f5b00 R08: 0000000000080000 R09: 0000000000000001
R10: 0000000000000003 R11: 0000000000000001 R12: ffff8880056b6a00
R13: ffff8880088f5280 R14: 0000000000000001 R15: ffff8880088f5a80
FS: 0000000000000000(0000) GS:ffff88807dd80000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000008 CR3: 0000000006314000 CR4: 00000000007506f0
PKRU: 55555554
Call Trace:
<TASK>
unix_release_sock (net/unix/af_unix.c:654)
unix_release (net/unix/af_unix.c:1050)
__sock_release (net/socket.c:660)
sock_close (net/socket.c:1423)
__fput (fs/file_table.c:423)
delayed_fput (fs/file_table.c:444 (discriminator 3))
process_one_work (kernel/workqueue.c:3259)
worker_thread (kernel/workqueue.c:3329 kernel/workqueue.c:3416)
kthread (kernel/kthread.c:388)
ret_from_fork (arch/x86/kernel/process.c:153)
ret_from_fork_asm (arch/x86/entry/entry_64.S:257)
</TASK>
Modules linked in:
CR2: 0000000000000008
Published: 2024-06-10
Score: 7.5 High
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

Analysis and contextual insights are available on OpenCVE Cloud.

Remediation

No vendor fix or workaround currently provided.

Additional remediation guidance may be available on OpenCVE Cloud.

Tracking

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Advisories
Source ID Title
Ubuntu USN Ubuntu USN USN-6999-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6999-2 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7004-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7005-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7005-2 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7007-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7007-2 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7007-3 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7008-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7009-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7009-2 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7019-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7029-1 Linux kernel vulnerabilities
History

Tue, 05 Nov 2024 10:15:00 +0000

Type Values Removed Values Added
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.8:-:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
Metrics ssvc

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


Thu, 05 Sep 2024 17:00:00 +0000

Type Values Removed Values Added
Metrics cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'}


Thu, 05 Sep 2024 04:30:00 +0000

Type Values Removed Values Added
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: 2026-05-11T20:18:10.475Z

Reserved: 2024-05-30T15:25:07.082Z

Link: CVE-2024-36972

cve-icon Vulnrichment

Updated: 2024-08-02T03:43:50.584Z

cve-icon NVD

Status : Analyzed

Published: 2024-06-10T15:15:52.617

Modified: 2025-04-01T18:36:27.320

Link: CVE-2024-36972

cve-icon Redhat

Severity : Moderate

Publid Date: 2024-06-10T00:00:00Z

Links: CVE-2024-36972 - Bugzilla

cve-icon OpenCVE Enrichment

No data.

Weaknesses