CVE-2021-47593
CVE.org · Published
- Record status
- Published
- Identifier year (not publication year)
- 2021
- Source publication
- Source updated
- Imported by cveboard
- Source snapshot
- cve_2026-10-24_midnight_baseline ·
CNA source text (English)
mptcp: clear 'kern' flag from fallback sockets
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 [..]
Scoped product and version facts
Fix information unknown; no fixed version is derived here. Missing information does not prove that no fix exists.
Exploitation unknown; this catalogue does not assess exploitation.
Linux
- Vendor
- Linux
- Product
- Linux
- Platforms
- Unknown
- Default status
unaffected
| Version (version) | Status (status) | Version scheme (versionType) | Exclusive end (lessThan) | Inclusive end (lessThanOrEqual) | Status changes (at → status) |
|---|---|---|---|---|---|
| cf7da0d66cc1a2a19fc5930bb746ffbb2d4cd1be | affected | git | 451f1eded7f56e93aaf52eb547ba97742d9c0e97 | Unavailable | None listed |
| cf7da0d66cc1a2a19fc5930bb746ffbb2d4cd1be | affected | git | c26ac0ea3a91c210cf90452e625dc441adf3e549 | Unavailable | None listed |
| cf7da0d66cc1a2a19fc5930bb746ffbb2d4cd1be | affected | git | d6692b3b97bdc165d150f4c1505751a323a80717 | Unavailable | None listed |
Linux
- Vendor
- Linux
- Product
- Linux
- Platforms
- Unknown
- Default status
affected
| Version (version) | Status (status) | Version scheme (versionType) | Exclusive end (lessThan) | Inclusive end (lessThanOrEqual) | Status changes (at → status) |
|---|---|---|---|---|---|
| 5.6 | affected | Unavailable | Unavailable | Unavailable | None listed |
| 0 | unaffected | semver | 5.6 | Unavailable | None listed |
| 5.10.88 | unaffected | semver | Unavailable | 5.10.* | None listed |
| 5.15.11 | unaffected | semver | Unavailable | 5.15.* | None listed |
| 5.16 | unaffected | original_commit_for_fix | Unavailable | * | None listed |