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 […]
OS | Version | Architecture | Package | Version | Filename |
---|---|---|---|---|---|
Debian | 12 | all | linux | < 5.15.15-1 | linux_5.15.15-1_all.deb |
Debian | 11 | all | linux | < 5.10.92-1 | linux_5.10.92-1_all.deb |
Debian | 999 | all | linux | < 5.15.15-1 | linux_5.15.15-1_all.deb |
Debian | 13 | all | linux | < 5.15.15-1 | linux_5.15.15-1_all.deb |