CVE-2024-36972
af_unix: Update unix_sk(sk)->oob_skb under sk_receive_queue lock.
Severity Score
Exploit Likelihood
Affected Versions
Public Exploits
0Exploited in Wild
-Decision
Descriptions
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
En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: af_unix: actualice unix_sk(sk)->oob_skb bajo el bloqueo sk_receive_queue. Billy Jheng Bing-Jhong informó de una ejecución entre __unix_gc() y queue_oob(). __unix_gc() intenta recolectar basura de sockets en vuelo close()d, y luego, si el socket tiene MSG_OOB en unix_sk(sk)->oob_skb, GC eliminará la referencia y establecerá NULL sin bloqueo. Sin embargo, el socket del par aún puede enviar el mensaje MSG_OOB y queue_oob() puede actualizar unix_sk(sk)->oob_skb simultáneamente, lo que lleva a la desreferencia del puntero NULL. [0] Para solucionar el problema, actualicemos unix_sk(sk)->oob_skb bajo el bloqueo de sk_receive_queue y lo llevemos a todos los lugares donde toquemos oob_skb. Tenga en cuenta que posponemos kfree_skb() en Manage_oob() para silenciar el falso positivo de Lockdep (consulte [1]). [0]: ERROR: desreferencia del puntero NULL del kernel, dirección: 0000000000000008 PF: acceso de escritura del supervisor en modo kernel PF: error_code(0x0002) - página no presente PGD 8000000009f5e067 P4D 8000000009f5e067 PUD 9f5d067 PMD 0 Ups: 02 [#1] SMP ADELANTADO PTI CPU: 3 PID: 50 Comm: kworker/3:1 No contaminado 6.9.0-rc5-00191-gd091e579b864 #110 Nombre del hardware: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0- gd239552ce722-prebuilt.qemu.org 01/04/2014 Cola de trabajo: eventos retrasados_fput RIP: 0010:skb_dequeue (./include/linux/skbuff.h:2386 ./include/linux/skbuff.h:2402 net/core/skbuff. c:3847) Código: 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 0 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: 80088f5ae8 RCX: 00000000361289f9 RDX: 0000000000000000 RSI: 0000000000000206 RDI: ffff8880088f5b00 RBP: ffff8880088f5b00 R08: 0000000000080000 R09: 0000000000000001 R10: 0000000000000003 R11: 00000000000000001 R12: ffff8880056b6a00 R13: ffff8880088f5280 R14: 0000000000000001 R15: ffff8880088f5a80 FS: 0000000000000000(0000) GS:ffff88807dd80000(0000) knlGS:00000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0 : 0000000080050033 CR2: 0000000000000008 CR3: 0000000006314000 CR4: 00000000007506f0 PKRU: 55555554 Seguimiento de llamadas: unix_release_sock (net/unix/af_unix.c:654) ix_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) retrasado_fput (fs/file_table.c:444 (discriminador 3)) Process_one_work (kernel/workqueue.c:3259) trabajador_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) Módulos vinculados en: CR2: 0000000000000008
CVSS Scores
SSVC
- Decision:Track*
Timeline
- 2024-05-30 CVE Reserved
- 2024-06-10 CVE Published
- 2024-06-13 EPSS Updated
- 2024-09-05 CVE Updated
- ---------- Exploited in Wild
- ---------- KEV Due Date
- ---------- First Exploit
CWE
- CWE-476: NULL Pointer Dereference
CAPEC
References (10)
| URL | Tag | Source |
|---|---|---|
| https://git.kernel.org/stable/c/4fe505c63aa3273135a57597fda761e9aecc7668 | Vuln. Introduced | |
| https://git.kernel.org/stable/c/e0e09186d8821ad59806115d347ea32efa43ca4b | Vuln. Introduced | |
| https://git.kernel.org/stable/c/b74aa9ce13d02b7fd37c5325b99854f91b9b4276 | Vuln. Introduced | |
| https://git.kernel.org/stable/c/1279f9d9dec2d7462823a18c29ad61359e0a007d | Vuln. Introduced | |
| https://git.kernel.org/stable/c/82ae47c5c3a6b27fdc0f9e83c1499cb439c56140 | Vuln. Introduced |
| URL | Date | SRC |
|---|
| URL | Date | SRC |
|---|
Affected Vendors, Products, and Versions
| Vendor | Product | Version | Other | Status | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Vendor | Product | Version | Other | Status | <-- --> | Vendor | Product | Version | Other | Status |
| Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | >= 5.15.149 < 5.15.161 Search vendor "Linux" for product "Linux Kernel" and version " >= 5.15.149 < 5.15.161" | en |
Affected
| ||||||
| Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | >= 6.1.78 < 6.1.93 Search vendor "Linux" for product "Linux Kernel" and version " >= 6.1.78 < 6.1.93" | en |
Affected
| ||||||
| Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | >= 6.6.17 < 6.6.33 Search vendor "Linux" for product "Linux Kernel" and version " >= 6.6.17 < 6.6.33" | en |
Affected
| ||||||
| Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | >= 6.8 < 6.9.4 Search vendor "Linux" for product "Linux Kernel" and version " >= 6.8 < 6.9.4" | en |
Affected
| ||||||
| Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | >= 6.8 < 6.10 Search vendor "Linux" for product "Linux Kernel" and version " >= 6.8 < 6.10" | en |
Affected
| ||||||
| Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | 6.7.5 Search vendor "Linux" for product "Linux Kernel" and version "6.7.5" | en |
Affected
| ||||||