CVE-2021-47591

2024-06-1915:15:53

416baaa9-dc9f-4396-8d5f-8c081fb06d67

web.nvd.nist.gov

linux kernel

vulnerability

tcp_ulp setsockopt

mptcp connections

crash

fallback mode

cve-2021-47591

6.5 Medium

AI Score

Confidence

Low

0.0004 Low

EPSS

Percentile

9.1%

JSON

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

mptcp: remove tcp ulp setsockopt support

TCP_ULP setsockopt cannot be used for mptcp because its already
used internally to plumb subflow (tcp) sockets to the mptcp layer.

syzbot managed to trigger a crash for mptcp connections that are
in fallback mode:

KASAN: null-ptr-deref in range [0x0000000000000020-0x0000000000000027]
CPU: 1 PID: 1083 Comm: syz-executor.3 Not tainted 5.16.0-rc2-syzkaller #0
RIP: 0010:tls_build_proto net/tls/tls_main.c:776 [inline]
[…]
__tcp_set_ulp net/ipv4/tcp_ulp.c:139 [inline]
tcp_set_ulp+0x428/0x4c0 net/ipv4/tcp_ulp.c:160
do_tcp_setsockopt+0x455/0x37c0 net/ipv4/tcp.c:3391
mptcp_setsockopt+0x1b47/0x2400 net/mptcp/sockopt.c:638

Remove support for TCP_ULP setsockopt.

Affected configurations

Vulners

Node

linuxlinux_kernelRange5.13–5.15.11

linuxlinux_kernelRange5.16.0≥

CNA Affected

[
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "unaffected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "net/mptcp/sockopt.c"
    ],
    "versions": [
      {
        "version": "d9e4c1291810",
        "lessThan": "3de0c86d42f8",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "d9e4c1291810",
        "lessThan": "404cd9a22150",
        "status": "affected",
        "versionType": "git"
      }
    ]
  },
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "affected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "net/mptcp/sockopt.c"
    ],
    "versions": [
      {
        "version": "5.13",
        "status": "affected"
      },
      {
        "version": "0",
        "lessThan": "5.13",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.15.11",
        "lessThanOrEqual": "5.15.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.16",
        "lessThanOrEqual": "*",
        "status": "unaffected",
        "versionType": "original_commit_for_fix"
      }
    ]
  }
]