CVE-2024-36904

tcp: Use refcount_inc_not_zero() in tcp_twsk_unique().

Severity Score

7.0

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

Track

*SSVC

Descriptions

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

tcp: Use refcount_inc_not_zero() in tcp_twsk_unique().

Anderson Nascimento reported a use-after-free splat in tcp_twsk_unique()
with nice analysis.

Since commit ec94c2696f0b ("tcp/dccp: avoid one atomic operation for
timewait hashdance"), inet_twsk_hashdance() sets TIME-WAIT socket's
sk_refcnt after putting it into ehash and releasing the bucket lock.

Thus, there is a small race window where other threads could try to
reuse the port during connect() and call sock_hold() in tcp_twsk_unique()
for the TIME-WAIT socket with zero refcnt.

If that happens, the refcnt taken by tcp_twsk_unique() is overwritten
and sock_put() will cause underflow, triggering a real use-after-free
somewhere else.

To avoid the use-after-free, we need to use refcount_inc_not_zero() in
tcp_twsk_unique() and give up on reusing the port if it returns false.

[0]:
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 0 PID: 1039313 at lib/refcount.c:25 refcount_warn_saturate+0xe5/0x110
CPU: 0 PID: 1039313 Comm: trigger Not tainted 6.8.6-200.fc39.x86_64 #1
Hardware name: VMware, Inc. VMware20,1/440BX Desktop Reference Platform, BIOS VMW201.00V.21805430.B64.2305221830 05/22/2023
RIP: 0010:refcount_warn_saturate+0xe5/0x110
Code: 42 8e ff 0f 0b c3 cc cc cc cc 80 3d aa 13 ea 01 00 0f 85 5e ff ff ff 48 c7 c7 f8 8e b7 82 c6 05 96 13 ea 01 01 e8 7b 42 8e ff <0f> 0b c3 cc cc cc cc 48 c7 c7 50 8f b7 82 c6 05 7a 13 ea 01 01 e8
RSP: 0018:ffffc90006b43b60 EFLAGS: 00010282
RAX: 0000000000000000 RBX: ffff888009bb3ef0 RCX: 0000000000000027
RDX: ffff88807be218c8 RSI: 0000000000000001 RDI: ffff88807be218c0
RBP: 0000000000069d70 R08: 0000000000000000 R09: ffffc90006b439f0
R10: ffffc90006b439e8 R11: 0000000000000003 R12: ffff8880029ede84
R13: 0000000000004e20 R14: ffffffff84356dc0 R15: ffff888009bb3ef0
FS: 00007f62c10926c0(0000) GS:ffff88807be00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020ccb000 CR3: 000000004628c005 CR4: 0000000000f70ef0
PKRU: 55555554
Call Trace:
<TASK>
? refcount_warn_saturate+0xe5/0x110
? __warn+0x81/0x130
? refcount_warn_saturate+0xe5/0x110
? report_bug+0x171/0x1a0
? refcount_warn_saturate+0xe5/0x110
? handle_bug+0x3c/0x80
? exc_invalid_op+0x17/0x70
? asm_exc_invalid_op+0x1a/0x20
? refcount_warn_saturate+0xe5/0x110
tcp_twsk_unique+0x186/0x190
__inet_check_established+0x176/0x2d0
__inet_hash_connect+0x74/0x7d0
? __pfx___inet_check_established+0x10/0x10
tcp_v4_connect+0x278/0x530
__inet_stream_connect+0x10f/0x3d0
inet_stream_connect+0x3a/0x60
__sys_connect+0xa8/0xd0
__x64_sys_connect+0x18/0x20
do_syscall_64+0x83/0x170
entry_SYSCALL_64_after_hwframe+0x78/0x80
RIP: 0033:0x7f62c11a885d
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 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 8b 0d a3 45 0c 00 f7 d8 64 89 01 48
RSP: 002b:00007f62c1091e58 EFLAGS: 00000296 ORIG_RAX: 000000000000002a
RAX: ffffffffffffffda RBX: 0000000020ccb004 RCX: 00007f62c11a885d
RDX: 0000000000000010 RSI: 0000000020ccb000 RDI: 0000000000000003
RBP: 00007f62c1091e90 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000296 R12: 00007f62c10926c0
R13: ffffffffffffff88 R14: 0000000000000000 R15: 00007ffe237885b0
</TASK>

En el kernel de Linux se ha resuelto la siguiente vulnerabilidad: tcp: utilice refcount_inc_not_zero() en tcp_twsk_unique(). Anderson Nascimento informó sobre un símbolo de use after free en tcp_twsk_unique() con un buen análisis. Desde el commit ec94c2696f0b ("tcp/dccp: evitar una operación atómica para timewait hashdance"), inet_twsk_hashdance() establece el sk_refcnt del socket TIME-WAIT después de ponerlo en ehash y liberar el bloqueo del depósito. Por lo tanto, hay una pequeña ventana de ejecución donde otros subprocesos podrían intentar reutilizar el puerto durante connect() y llamar a sock_hold() en tcp_twsk_unique() para el socket TIME-WAIT con cero refcnt. Si eso sucede, el refcnt tomado por tcp_twsk_unique() se sobrescribe y sock_put() provocará un desbordamiento insuficiente, lo que desencadenará un use after free real en otro lugar. Para evitar el use after free, debemos usar refcount_inc_not_zero() en tcp_twsk_unique() y renunciar a reutilizar el puerto si devuelve falso. [0]: refcount_t: suma en 0; use after free. ADVERTENCIA: CPU: 0 PID: 1039313 en lib/refcount.c:25 refcount_warn_saturate+0xe5/0x110 CPU: 0 PID: 1039313 Comm: disparador No contaminado 6.8.6-200.fc39.x86_64 #1 Nombre de hardware: VMware, Inc. Plataforma de referencia de escritorio VMware20,1/440BX, BIOS VMW201.00V.21805430.B64.2305221830 22/05/2023 RIP: 0010:refcount_warn_saturate+0xe5/0x110 Código: 42 8e ff 0f 0b c3 cc cc cc 80 3d aa 13 cada uno 01 00 0f 85 5e ff ff 48 c7 c7 f8 8e b7 82 c6 05 96 13 ea 01 01 e8 7b 42 8e ff <0f> 0b c3 cc cc cc cc 48 c7 c7 50 8f b7 82 c6 05 7a 13 ea 0 1 e8 RSP: 0018:ffffc90006b43b60 EFLAGS: 00010282 RAX: 0000000000000000 RBX: ffff888009bb3ef0 RCX: 00000000000000027 RDX: ffff88807be218c8 RSI: 00000000001 RDI: ffff88807be218c0 RBP: 0000000000069d70 R08: 0000000000000000 R09: ffffc90006b439f0 R10: ffffc90006b439e8 R11: 000000000000 0003 R12: ffff8880029ede84 R13: 0000000000004e20 R14: ffffffff84356dc0 R15: ffff888009bb3ef0 FS: 00007f62c10926c0(0000) GS:ffff88807be00000(0000) knlGS:00000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020ccb000 CR3: 000000004628c005 CR4: 0000000000f70ef0 PKRU: 55555554 Seguimiento de llamadas: ? refcount_warn_saturate+0xe5/0x110? __advertir+0x81/0x130 ? refcount_warn_saturate+0xe5/0x110? report_bug+0x171/0x1a0? refcount_warn_saturate+0xe5/0x110? handle_bug+0x3c/0x80? exc_invalid_op+0x17/0x70? asm_exc_invalid_op+0x1a/0x20? refcount_warn_saturate+0xe5/0x110 tcp_twsk_unique+0x186/0x190 __inet_check_establecido+0x176/0x2d0 __inet_hash_connect+0x74/0x7d0 ? __pfx___inet_check_establecido+0x10/0x10 tcp_v4_connect+0x278/0x530 __inet_stream_connect+0x10f/0x3d0 inet_stream_connect+0x3a/0x60 __sys_connect+0xa8/0xd0 __x64_sys_connect+0x18/0x20 _64+0x83/0x170 entrada_SYSCALL_64_after_hwframe+0x78/0x80 RIP: 0033:0x7f62c11a885d Código: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 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 73 01 c3 48 8b 0d a3 45 0c 00 f7 d8 64 89 01 48 RSP: 002b:00007f62c1091e58 EFLAGS: 00000296 ORIG_RAX: 0000000000000002a RAX: ffffffffffffffda RBX: 20ccb004 RCX: 00007f62c11a885d RDX: 00000000000000010 RSI: 0000000020ccb000 RDI: 0000000000000003 RBP: 00007f62c1091e90 R08: 0000000000000 0000R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000296 R12: 00007f62c10926c0 R13: ffffffffffffff88 R14: 0000000000000000 R15: 07ffe237885b0

A use-after-free flaw was found in the Linux kernel’s TCP protocol in how a local user triggers a complex race condition during connection to the socket. This flaw allows a local user to crash or potentially escalate their privileges on the system.

*Credits: N/A

CVSS Scores

Red Hatv3.1 7.0

Attack Vector

Local

Attack Complexity

High

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

* Common Vulnerability Scoring System

SSVC

Decision:Track

Exploitation

None

Automatable

Tech. Impact

Partial

* Organization's Worst-case Scenario

Timeline

2024-05-30 CVE Reserved
2024-05-30 CVE Published
2024-05-31 EPSS Updated
2024-12-19 CVE Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CWE-416: Use After Free

CAPEC

References (13)

URL	Tag	Source
https://git.kernel.org/stable/c/ec94c2696f0bcd5ae92a553244e4ac30d2171a2d	Vuln. Introduced
https://lists.debian.org/debian-lts-announce/2024/06/msg00019.html
https://lists.debian.org/debian-lts-announce/2024/06/msg00020.html

URL	Date	SRC

URL	Date	SRC
https://git.kernel.org/stable/c/84546cc1aeeb4df3e444b18a4293c9823f974be9	2024-05-17
https://git.kernel.org/stable/c/1796ca9c6f5bd50554214053af5f47d112818ee3	2024-05-17
https://git.kernel.org/stable/c/1d9cf07810c30ef7948879567d10fd1f01121d34	2024-05-17
https://git.kernel.org/stable/c/27b0284d8be182a81feb65581ab6a724dfd596e8	2024-05-17
https://git.kernel.org/stable/c/13ed7cdf079686ccd3618335205700c03f6fb446	2024-05-17
https://git.kernel.org/stable/c/6e48faad92be13166184d21506e4e54c79c13adc	2024-05-17
https://git.kernel.org/stable/c/517e32ea0a8c72202d0d8aa8df50a7cd3d6fdefc	2024-05-17
https://git.kernel.org/stable/c/f2db7230f73a80dbb179deab78f88a7947f0ab7e	2024-05-03

URL	Date	SRC
https://access.redhat.com/security/cve/CVE-2024-36904	2024-09-03
https://bugzilla.redhat.com/show_bug.cgi?id=2284541	2024-09-03

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"				>= 4.16 < 4.19.314 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.16 < 4.19.314"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 4.16 < 5.4.276 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.16 < 5.4.276"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 4.16 < 5.10.217 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.16 < 5.10.217"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 4.16 < 5.15.159 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.16 < 5.15.159"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 4.16 < 6.1.91 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.16 < 6.1.91"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 4.16 < 6.6.31 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.16 < 6.6.31"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 4.16 < 6.8.10 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.16 < 6.8.10"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 4.16 < 6.9 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.16 < 6.9"		en		Affected