// For flags

CVE-2024-26640

tcp: add sanity checks to rx zerocopy

Severity Score

5.5
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

Track
*SSVC
Descriptions

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

tcp: add sanity checks to rx zerocopy

TCP rx zerocopy intent is to map pages initially allocated
from NIC drivers, not pages owned by a fs.

This patch adds to can_map_frag() these additional checks:

- Page must not be a compound one.
- page->mapping must be NULL.

This fixes the panic reported by ZhangPeng.

syzbot was able to loopback packets built with sendfile(),
mapping pages owned by an ext4 file to TCP rx zerocopy.

r3 = socket$inet_tcp(0x2, 0x1, 0x0)
mmap(&(0x7f0000ff9000/0x4000)=nil, 0x4000, 0x0, 0x12, r3, 0x0)
r4 = socket$inet_tcp(0x2, 0x1, 0x0)
bind$inet(r4, &(0x7f0000000000)={0x2, 0x4e24, @multicast1}, 0x10)
connect$inet(r4, &(0x7f00000006c0)={0x2, 0x4e24, @empty}, 0x10)
r5 = openat$dir(0xffffffffffffff9c, &(0x7f00000000c0)='./file0\x00',
0x181e42, 0x0)
fallocate(r5, 0x0, 0x0, 0x85b8)
sendfile(r4, r5, 0x0, 0x8ba0)
getsockopt$inet_tcp_TCP_ZEROCOPY_RECEIVE(r4, 0x6, 0x23,
&(0x7f00000001c0)={&(0x7f0000ffb000/0x3000)=nil, 0x3000, 0x0, 0x0, 0x0,
0x0, 0x0, 0x0, 0x0}, &(0x7f0000000440)=0x40)
r6 = openat$dir(0xffffffffffffff9c, &(0x7f00000000c0)='./file0\x00',
0x181e42, 0x0)

En el kernel de Linux, se resolvió la siguiente vulnerabilidad: tcp: agregue controles de seguridad a rx zerocopy La intención de TCP rx zerocopy es mapear páginas inicialmente asignadas desde controladores NIC, no páginas propiedad de un fs. Este parche añade a can_map_frag() estas comprobaciones adicionales: - La página no debe ser compuesta. - página->mapeo debe ser NULL. Esto soluciona el pánico informado por ZhangPeng. syzbot pudo realizar un loopback de paquetes creados con sendfile(), asignando páginas propiedad de un archivo ext4 a TCP rx zerocopy. r3 = socket$inet_tcp(0x2, 0x1, 0x0) mmap(&(0x7f0000ff9000/0x4000)=nil, 0x4000, 0x0, 0x12, r3, 0x0) r4 = socket$inet_tcp(0x2, 0x1, 0x0) bind$inet(r4 , &(0x7f0000000000)={0x2, 0x4e24, @multicast1}, 0x10) connect$inet(r4, &(0x7f00000006c0)={0x2, 0x4e24, @empty}, 0x10) r5 = openat$dir(0xffffffffffffff9c, &(0x7f00) 000000c0 )='./file0\x00', 0x181e42, 0x0) fallocate(r5, 0x0, 0x0, 0x85b8) sendfile(r4, r5, 0x0, 0x8ba0) getsockopt$inet_tcp_TCP_ZEROCOPY_RECEIVE(r4, 0x6, 0x23, &(0x7f00000) 001c0)={ &(0x7f0000ffb000/0x3000)=nil, 0x3000, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0}, &(0x7f0000000440)=0x40) r6 = openat$dir(0xffffffffffffff9c, &(0x7f000) 00000c0)='./archivo0 \x00', 0x181e42, 0x0)

A vulnerability was found in Linux Kernel where rx zerocopy feature allowed mapping of pages owned by the filesystem, leading to potential system panic which is caused by the lack of sanity checks to rx zerocopy. A local authenticated attacker could exploit this vulnerability to cause a denial of service.

*Credits: N/A
CVSS Scores
Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High
* Common Vulnerability Scoring System
SSVC
  • Decision:Track
Exploitation
None
Automatable
No
Tech. Impact
Partial
* Organization's Worst-case Scenario
Timeline
  • 2024-02-19 CVE Reserved
  • 2024-03-18 CVE Published
  • 2024-03-19 EPSS Updated
  • 2024-12-19 CVE Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-20: Improper Input Validation
CAPEC
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"
>= 4.18 < 5.10.210
Search vendor "Linux" for product "Linux Kernel" and version " >= 4.18 < 5.10.210"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 4.18 < 5.15.149
Search vendor "Linux" for product "Linux Kernel" and version " >= 4.18 < 5.15.149"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 4.18 < 6.1.77
Search vendor "Linux" for product "Linux Kernel" and version " >= 4.18 < 6.1.77"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 4.18 < 6.6.16
Search vendor "Linux" for product "Linux Kernel" and version " >= 4.18 < 6.6.16"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 4.18 < 6.7.4
Search vendor "Linux" for product "Linux Kernel" and version " >= 4.18 < 6.7.4"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 4.18 < 6.8
Search vendor "Linux" for product "Linux Kernel" and version " >= 4.18 < 6.8"
en
Affected