CVE-2021-4442

In the Linux kernel, the following vulnerability has been resolved: tcp: add sanity tests to TCP_QUEUE_SEQ Qingyu Li reported a syzkaller bug where the repro changes RCV SEQ _after_ restoring data in the receive queue. mprotect(0x4aa000, 12288, PROT_READ) = 0 mmap(0x1ffff000, 4096, PROT_NONE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x1ffff000 mmap(0x20000000, 16777216, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x20000000 mmap(0x21000000, 4096, PROT_NONE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x21000000 socket(AF_INET6, SOCK_STREAM, IPPROTO_IP) = 3 setsockopt(3, SOL_TCP, TCP_REPAIR, [1], 4) = 0 connect(3, {sa_family=AF_INET6, sin6_port=htons(0), sin6_flowinfo=htonl(0), inet_pton(AF_INET6, "::1", &sin6_addr), sin6_scope_id=0}, 28) = 0 setsockopt(3, SOL_TCP, TCP_REPAIR_QUEUE, [1], 4) = 0 sendmsg(3, {msg_name=NULL, msg_namelen=0, msg_iov=[{iov_base="0x0000000000000003\0\0", iov_len=20}], msg_iovlen=1, msg_controllen=0, msg_flags=0}, 0) = 20 setsockopt(3, SOL_TCP, TCP_REPAIR, [0], 4) = 0 setsockopt(3, SOL_TCP, TCP_QUEUE_SEQ, [128], 4) = 0 recvfrom(3, NULL, 20, 0, NULL, NULL) = -1 ECONNRESET (Connection reset by peer) syslog shows: [ 111.205099] TCP recvmsg seq # bug 2: copied 80, seq 0, rcvnxt 80, fl 0 [ 111.207894] WARNING: CPU: 1 PID: 356 at net/ipv4/tcp.c:2343 tcp_recvmsg_locked+0x90e/0x29a0 This should not be allowed. TCP_QUEUE_SEQ should only be used when queues are empty. This patch fixes this case, and the tx path as well.

CVSS v3 5.5 MEDIUM

5.5^/10

CVSS v3 : MEDIUM

V3 Legend

Vector :

Exploitability : 1.8 / Impact : 3.6

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://git.kernel.org/stable/c/046f3c1c2ff450fb7ae53650e9a95e0074a61f3e	Exploit Patch
https://git.kernel.org/stable/c/319f460237fc2965a80aa9a055044e1da7b3692a	Exploit Patch
https://git.kernel.org/stable/c/3b72d5a703842f582502d97906f17d6ee122dac2	Exploit Patch
https://git.kernel.org/stable/c/3bf899438c123c444f6b644a57784dfbb6b15ad6	Exploit Patch
https://git.kernel.org/stable/c/8811f4a9836e31c14ecdf79d9f3cb7c5d463265d	Exploit Patch

Configurations

Configuration 1 (hide)

OR	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel:5.12:rc1::::::
	cpe:2.3:o:linux:linux_kernel:5.12:rc2::::::

History

12 Sep 2024, 16:58

Type	Values Removed	Values Added
CWE		NVD-CWE-noinfo
References	~~() https://git.kernel.org/stable/c/046f3c1c2ff450fb7ae53650e9a95e0074a61f3e -~~	() https://git.kernel.org/stable/c/046f3c1c2ff450fb7ae53650e9a95e0074a61f3e - Exploit, Patch
References	~~() https://git.kernel.org/stable/c/319f460237fc2965a80aa9a055044e1da7b3692a -~~	() https://git.kernel.org/stable/c/319f460237fc2965a80aa9a055044e1da7b3692a - Exploit, Patch
References	~~() https://git.kernel.org/stable/c/3b72d5a703842f582502d97906f17d6ee122dac2 -~~	() https://git.kernel.org/stable/c/3b72d5a703842f582502d97906f17d6ee122dac2 - Exploit, Patch
References	~~() https://git.kernel.org/stable/c/3bf899438c123c444f6b644a57784dfbb6b15ad6 -~~	() https://git.kernel.org/stable/c/3bf899438c123c444f6b644a57784dfbb6b15ad6 - Exploit, Patch
References	~~() https://git.kernel.org/stable/c/8811f4a9836e31c14ecdf79d9f3cb7c5d463265d -~~	() https://git.kernel.org/stable/c/8811f4a9836e31c14ecdf79d9f3cb7c5d463265d - Exploit, Patch
Summary		(es) En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: tcp: agregar pruebas de cordura a TCP_QUEUE_SEQ Qingyu Li informó un error de syzkaller donde la reproducción cambia RCV SEQ _después_ de restaurar datos en la cola de recepción. mprotect(0x4aa000, 12288, PROT_LECTURA) = 0 mmap(0x1ffff000, 4096, PROT_NINGUNO, MAPA_PRIVADO\|MAPA_FIJO\|MAPA_ANÓNIMO, -1, 0) = 0x1ffff000 mmap(0x20000000, 16777216, PROT_LECTURA\|PROT_ESCRITURA\|PROT_EJECUCIÓN, MAPA_PRIVADO\|MAPA_FIJO\|MAPA_ANÓNIMO, -1, 0) = 0x20000000 mmap(0x21000000, 4096, PROT_NINGUNO, MAPA_PRIVADO\|MAPA_FIJO\|MAPA_ANÓNIMO, -1, 0) = 0x21000000 socket(AF_INET6, SOCK_STREAM, IPPROTO_IP) = 3 setsockopt(3, SOL_TCP, TCP_REPAIR, [1], 4) = 0 connect(3, {sa_family=AF_INET6, sin6_port=htons(0), sin6_flowinfo=htonl(0), inet_pton(AF_INET6, "::1", &sin6_addr), sin6_scope_id=0}, 28) = 0 setsockopt(3, SOL_TCP, TCP_REPAIR_QUEUE, [1], 4) = 0 sendmsg(3, {msg_name=NULL, msg_namelen=0, msg_iov=[{iov_base="0x0000000000000003\0\0", iov_len=20}], msg_iovlen=1, msg_controllen=0, msg_flags=0}, 0) = 20 setsockopt(3, SOL_TCP, TCP_REPAIR, [0], 4) = 0 setsockopt(3, SOL_TCP, TCP_QUEUE_SEQ, [128], 4) = 0 recvfrom(3, NULL, 20, 0, NULL, NULL) = -1 ECONNRESET (Conexión restablecida por el par) syslog muestra: [ 111.205099] TCP recvmsg seq # error 2: copiado 80, seq 0, rcvnxt 80, fl 0 [ 111.207894] ADVERTENCIA: CPU: 1 PID: 356 en net/ipv4/tcp.c:2343 tcp_recvmsg_locked+0x90e/0x29a0 Esto no debería estar permitido. TCP_QUEUE_SEQ solo se debe utilizar cuando las colas están vacías. Este parche corrige este caso y también la ruta de transmisión.
CPE		cpe:2.3:o:linux:linux_kernel:::::::: cpe:2.3:o:linux:linux_kernel:5.12:rc1:::::: cpe:2.3:o:linux:linux_kernel:5.12:rc2::::::
First Time		Linux linux Kernel Linux
CVSS	v2 : ~~unknown~~ v3 : ~~unknown~~	v2 : unknown v3 : 5.5

29 Aug 2024, 11:15

Type	Values Removed	Values Added
New CVE

Information

Published : 2024-08-29 11:15

Updated : 2024-09-12 16:58

NVD link : CVE-2021-4442

Mitre link : CVE-2021-4442

CVE.ORG link : CVE-2021-4442

JSON object : View

Products Affected

linux

linux_kernel

CWE

NVD-CWE-noinfo

5.5 /10