CVEvulnerability

CVE-2021-47593

5.5 MEDIUM Published 2024-06-19 Modified 2026-06-17 Official page ↗
Status
Modified
Published
2024-06-19
Last modified
2026-06-17
Assigner
416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS 3.1 ([email protected])
5.5 MEDIUM — CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Weaknesses
CWE-476

Description

In the Linux kernel, the following vulnerability has been resolved: mptcp: clear 'kern' flag from fallback sockets The mptcp ULP extension relies on sk->sk_sock_kern being set correctly: It prevents setsockopt(fd, IPPROTO_TCP, TCP_ULP, "mptcp", 6); from working for plain tcp sockets (any userspace-exposed socket). But in case of fallback, accept() can return a plain tcp sk. In such case, sk is still tagged as 'kernel' and setsockopt will work. This will crash the kernel, The subflow extension has a NULL ctx->conn mptcp socket: BUG: KASAN: null-ptr-deref in subflow_data_ready+0x181/0x2b0 Call Trace: tcp_data_ready+0xf8/0x370 [..]

Affected configurations

• linux linux kernel (>= 5.6 < 5.10.88) • linux linux kernel (>= 5.11 < 5.15.11) • linux linux kernel 5.16

Related

Weakness · CWE (1)

  • CWE-476 NULL Pointer Dereference weakness

References