CVE-2024-26640 tcp: add sanity checks to rx zerocopy

2024-03-1810:19:07

Linux

github.com

linux kernel

tcp rx zerocopy

nic drivers

panic

zhangpeng

syzbot

sendfile()

ext4 file

fallocate

getsockopt

cve

AI Score

6.6

Confidence

Low

SSVC

Exploitation

none

Automatable

Technical Impact

partial

JSON

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)

CNA Affected

[
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "93ab6cc69162",
        "lessThan": "f48bf9a83b16",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "93ab6cc69162",
        "lessThan": "718f446e6031",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "93ab6cc69162",
        "lessThan": "b383d4ea272f",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "93ab6cc69162",
        "lessThan": "d15cc0f66884",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "93ab6cc69162",
        "lessThan": "1b8adcc0e2c5",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "93ab6cc69162",
        "lessThan": "577e4432f3ac",
        "versionType": "git"
      }
    ],
    "programFiles": [
      "net/ipv4/tcp.c"
    ],
    "defaultStatus": "unaffected"
  },
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "4.18"
      },
      {
        "status": "unaffected",
        "version": "0",
        "lessThan": "4.18",
        "versionType": "custom"
      },
      {
        "status": "unaffected",
        "version": "5.10.210",
        "versionType": "custom",
        "lessThanOrEqual": "5.10.*"
      },
      {
        "status": "unaffected",
        "version": "5.15.149",
        "versionType": "custom",
        "lessThanOrEqual": "5.15.*"
      },
      {
        "status": "unaffected",
        "version": "6.1.77",
        "versionType": "custom",
        "lessThanOrEqual": "6.1.*"
      },
      {
        "status": "unaffected",
        "version": "6.6.16",
        "versionType": "custom",
        "lessThanOrEqual": "6.6.*"
      },
      {
        "status": "unaffected",
        "version": "6.7.4",
        "versionType": "custom",
        "lessThanOrEqual": "6.7.*"
      },
      {
        "status": "unaffected",
        "version": "6.8",
        "versionType": "original_commit_for_fix",
        "lessThanOrEqual": "*"
      }
    ],
    "programFiles": [
      "net/ipv4/tcp.c"
    ],
    "defaultStatus": "affected"
  }
]