| Name | CVE-2021-47593 |
| 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 [..] |
| Source | CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more) |
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|---|---|---|
| linux (PTS) | buster | 4.19.249-2 | fixed |
| buster (security) | 4.19.316-1 | fixed | |
| bullseye (security), bullseye | 5.10.218-1 | fixed | |
| bookworm | 6.1.94-1 | fixed | |
| bookworm (security) | 6.1.90-1 | fixed | |
| trixie | 6.8.12-1 | fixed | |
| sid | 6.9.7-1 | fixed |
The information below is based on the following data on fixed versions.
| Package | Type | Release | Fixed Version | Urgency | Origin | Debian Bugs |
|---|---|---|---|---|---|---|
| linux | source | buster | (not affected) | |||
| linux | source | bullseye | 5.10.92-1 | |||
| linux | source | (unstable) | 5.15.15-1 |
[buster] - linux <not-affected> (Vulnerable code not present)
https://git.kernel.org/linus/d6692b3b97bdc165d150f4c1505751a323a80717 (5.16-rc6)