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| author | Jérémy Jean <Jeremy.Jean@oss.cyber.gouv.fr> | 2026-08-04 20:00:42 +0000 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2026-08-07 15:02:32 -0700 |
| commit | 3dbb44d88b1e94dd31fe43588af7437b34b44d56 (patch) | |
| tree | 26242fe0a42c2b841529ddd45ec9dbff429a9727 /include | |
| parent | 594d905195024b228c962627ae5ae7c17bd582a4 (diff) | |
| download | linux-next-3dbb44d88b1e94dd31fe43588af7437b34b44d56.tar.gz linux-next-3dbb44d88b1e94dd31fe43588af7437b34b44d56.zip | |
sctp: validate cookie AUTH state before use
When cookie authentication is disabled, COOKIE_ECHO restores fixed-size
AUTH fields directly from peer-controlled cookie bytes. A forged RANDOM
length, HMAC list, or CHUNKS list can then reach association consumers
with lengths or identifiers that were never validated against the local
backing arrays.
A forged RANDOM length can cause out-of-bounds reads during key-vector
construction. A forged HMAC identifier also caused a 32-byte write past
a zero-length AUTH chunk, providing a primitive for a local privilege
escalation chain.
Validate the cookie's RANDOM, HMACS, and CHUNKS parameters at the cookie
trust boundary before copying them into the association. Reject invalid
types, malformed lengths, unsupported HMAC identifiers, HMAC lists
without SHA1, and forbidden chunk ids.
Fixes: bbd0d59809f9 ("[SCTP]: Implement the receive and verification of AUTH chunk")
Fixes: 1f485649f529 ("[SCTP]: Implement SCTP-AUTH internals")
Signed-off-by: Jérémy Jean <Jeremy.Jean@oss.cyber.gouv.fr>
Acked-by: Xin Long <lucien.xin@gmail.com>
Link: https://patch.msgid.link/20260804200042.2412009-1-Jeremy.Jean@oss.cyber.gouv.fr
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/net/sctp/auth.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/include/net/sctp/auth.h b/include/net/sctp/auth.h index 6f2cd562b1de..74b3790e2a3d 100644 --- a/include/net/sctp/auth.h +++ b/include/net/sctp/auth.h @@ -22,6 +22,7 @@ struct sctp_endpoint; struct sctp_association; struct sctp_authkey; struct sctp_hmacalgo; +struct sctp_cookie; /* Defines an HMAC algorithm supported by SCTP chunk authentication */ struct sctp_hmac { @@ -72,6 +73,8 @@ struct sctp_shared_key *sctp_auth_get_shkey( int sctp_auth_asoc_copy_shkeys(const struct sctp_endpoint *ep, struct sctp_association *asoc, gfp_t gfp); +bool sctp_auth_verify_cookie_params(const struct sctp_endpoint *ep, + const struct sctp_cookie *cookie); const struct sctp_hmac *sctp_auth_get_hmac(__u16 hmac_id); const struct sctp_hmac * sctp_auth_asoc_get_hmac(const struct sctp_association *asoc); |