CVE-2024-36889
mptcp: ensure snd_nxt is properly initialized on connect
Severity Score
Exploit Likelihood
Affected Versions
Public Exploits
0Exploited in Wild
-Decision
Descriptions
In the Linux kernel, the following vulnerability has been resolved:
mptcp: ensure snd_nxt is properly initialized on connect
Christoph reported a splat hinting at a corrupted snd_una:
WARNING: CPU: 1 PID: 38 at net/mptcp/protocol.c:1005 __mptcp_clean_una+0x4b3/0x620 net/mptcp/protocol.c:1005
Modules linked in:
CPU: 1 PID: 38 Comm: kworker/1:1 Not tainted 6.9.0-rc1-gbbeac67456c9 #59
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2.el7 04/01/2014
Workqueue: events mptcp_worker
RIP: 0010:__mptcp_clean_una+0x4b3/0x620 net/mptcp/protocol.c:1005
Code: be 06 01 00 00 bf 06 01 00 00 e8 a8 12 e7 fe e9 00 fe ff ff e8
8e 1a e7 fe 0f b7 ab 3e 02 00 00 e9 d3 fd ff ff e8 7d 1a e7 fe
<0f> 0b 4c 8b bb e0 05 00 00 e9 74 fc ff ff e8 6a 1a e7 fe 0f 0b e9
RSP: 0018:ffffc9000013fd48 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffff8881029bd280 RCX: ffffffff82382fe4
RDX: ffff8881003cbd00 RSI: ffffffff823833c3 RDI: 0000000000000001
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: fefefefefefefeff R12: ffff888138ba8000
R13: 0000000000000106 R14: ffff8881029bd908 R15: ffff888126560000
FS: 0000000000000000(0000) GS:ffff88813bd00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f604a5dae38 CR3: 0000000101dac002 CR4: 0000000000170ef0
Call Trace:
<TASK>
__mptcp_clean_una_wakeup net/mptcp/protocol.c:1055 [inline]
mptcp_clean_una_wakeup net/mptcp/protocol.c:1062 [inline]
__mptcp_retrans+0x7f/0x7e0 net/mptcp/protocol.c:2615
mptcp_worker+0x434/0x740 net/mptcp/protocol.c:2767
process_one_work+0x1e0/0x560 kernel/workqueue.c:3254
process_scheduled_works kernel/workqueue.c:3335 [inline]
worker_thread+0x3c7/0x640 kernel/workqueue.c:3416
kthread+0x121/0x170 kernel/kthread.c:388
ret_from_fork+0x44/0x50 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243
</TASK>
When fallback to TCP happens early on a client socket, snd_nxt
is not yet initialized and any incoming ack will copy such value
into snd_una. If the mptcp worker (dumbly) tries mptcp-level
re-injection after such ack, that would unconditionally trigger a send
buffer cleanup using 'bad' snd_una values.
We could easily disable re-injection for fallback sockets, but such
dumb behavior already helped catching a few subtle issues and a very
low to zero impact in practice.
Instead address the issue always initializing snd_nxt (and write_seq,
for consistency) at connect time.
En el kernel de Linux, se resolvió la siguiente vulnerabilidad: mptcp: asegúrese de que snd_nxt se inicialice correctamente al conectar Christoph informó un símbolo que indica un snd_una dañado: ADVERTENCIA: CPU: 1 PID: 38 en net/mptcp/protocol.c:1005 __mptcp_clean_una +0x4b3/0x620 net/mptcp/protocol.c:1005 Módulos vinculados en: CPU: 1 PID: 38 Comm: kworker/1:1 No contaminado 6.9.0-rc1-gbbeac67456c9 #59 Nombre del hardware: PC estándar QEMU (i440FX + PIIX, 1996), BIOS 1.11.0-2.el7 01/04/2014 Cola de trabajo: eventos mptcp_worker RIP: 0010:__mptcp_clean_una+0x4b3/0x620 net/mptcp/protocol.c:1005 Código: be 06 01 00 00 bf 06 01 00 00 e8 a8 12 e7 fe e9 00 fe ff ff e8 8e 1a e7 fe 0f b7 ab 3e 02 00 00 e9 d3 fd ff ff e8 7d 1a e7 fe <0f> 0b 4c 8b bb e0 05 00 00 e9 74 fc ff ff e8 6a 1a e7 fe 0f 0b e9 RSP: 0018:ffffc9000013fd48 EFLAGS: 00010293 RAX: 0000000000000000 RBX: ffff8881029bd280 RCX: ffffffff82382fe4 RDX: 3cbd00 RSI: ffffffff823833c3 RDI: 0000000000000001 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000 R10: 00000000000000000 R11: fefefefefefefeff R12 : ffff888138ba8000 R13: 0000000000000106 R14: ffff8881029bd908 R15: ffff888126560000 FS: 00000000000000000(0000) GS:ffff88813bd00000(0000) nlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f604a5dae38 CR3: 0000000101dac002 CR4: 0000000000170ef0 Rastreo de llamadas: __mptcp_clean_una_wakeup net/mptcp/protocol.c:1055 [en línea] mptcp_clean_una_wakeup net/mptcp/protocol.c:1062 [en línea] __mptcp_retrans+0x7f/0x7e0 net/mptcp/protocol.c:2615 mptcp_worker+0x434/ 0x740 neto/ mptcp/protocol.c:2767 Process_one_work+0x1e0/0x560 kernel/workqueue.c:3254 Process_scheduled_works kernel/workqueue.c:3335 [en línea] work_thread+0x3c7/0x640 kernel/workqueue.c:3416 kthread+0x121/0x170 kernel/kthread .c:388 ret_from_fork+0x44/0x50 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243 Cuando el retorno a TCP ocurre temprano en un socket de cliente , snd_nxt aún no está inicializado y cualquier confirmación entrante copiará dicho valor en snd_una. Si el trabajador mptcp (tontamente) intenta la reinyección a nivel de mptcp después de tal confirmación, eso desencadenaría incondicionalmente una sanitización del búfer de envío utilizando valores snd_una 'incorrectos'. Podríamos desactivar fácilmente la reinyección para los sockets de respaldo, pero un comportamiento tan tonto ya ayudó a detectar algunos problemas sutiles y un impacto de muy bajo a cero en la práctica. En su lugar, resuelva el problema siempre inicializando snd_nxt (y write_seq, para mantener la coherencia) en el momento de la conexión.
CVSS Scores
SSVC
- Decision:Track
Timeline
- 2024-05-30 CVE Reserved
- 2024-05-30 CVE Published
- 2024-05-31 EPSS Updated
- 2024-08-02 CVE Updated
- ---------- Exploited in Wild
- ---------- KEV Due Date
- ---------- First Exploit
CWE
- CWE-665: Improper Initialization
CAPEC
References (10)
| URL | Tag | Source |
|---|---|---|
| https://git.kernel.org/stable/c/8fd738049ac3d67a937d36577763b47180aae1ad | Vuln. Introduced | |
| https://lists.debian.org/debian-lts-announce/2024/06/msg00019.html |
|
| URL | Date | SRC |
|---|
| URL | Date | SRC |
|---|---|---|
| https://access.redhat.com/security/cve/CVE-2024-36889 | 2024-09-24 | |
| https://bugzilla.redhat.com/show_bug.cgi?id=2284571 | 2024-09-24 |
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" | >= 5.9 < 5.10.218 Search vendor "Linux" for product "Linux Kernel" and version " >= 5.9 < 5.10.218" | en |
Affected
| ||||||
| Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | >= 5.9 < 5.15.159 Search vendor "Linux" for product "Linux Kernel" and version " >= 5.9 < 5.15.159" | en |
Affected
| ||||||
| Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | >= 5.9 < 6.1.91 Search vendor "Linux" for product "Linux Kernel" and version " >= 5.9 < 6.1.91" | en |
Affected
| ||||||
| Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | >= 5.9 < 6.6.31 Search vendor "Linux" for product "Linux Kernel" and version " >= 5.9 < 6.6.31" | en |
Affected
| ||||||
| Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | >= 5.9 < 6.8.10 Search vendor "Linux" for product "Linux Kernel" and version " >= 5.9 < 6.8.10" | en |
Affected
| ||||||
| Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | >= 5.9 < 6.9 Search vendor "Linux" for product "Linux Kernel" and version " >= 5.9 < 6.9" | en |
Affected
| ||||||