-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 Salutations, To all, please see below for cve request on oss-security. Regards, Mark

Description of the problem: For a TCP-style socket, while processing the COOKIE_ECHO chunk in sctp_sf_do_5_1D_ce(), after it has passed a series of sanity check, a new association would be created in sctp_unpack_cookie(), but afterwards, some processing maybe failed, and sctp_association_free() will be called to free the previously allocated association, in sctp_association_free(), sk_ack_backlog value is decremented for this socket, since the initial value for sk_ack_backlog is 0, after the decrement, it will be 65535, a wrap-around problem happens, and if we want to establish new associations afterward in the same socket, ABORT would be triggered since sctp deem the accept queue as full.

A remote attacker can block further connection to the particular sctp server socket by sending a specially crafted sctp packet.

Upstream patch: https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=d...

References: https://bugzilla.redhat.com/show_bug.cgi?id=1113967

Thanks, -- Petr Matousek / Red Hat Product Security PGP: 0xC44977CA 8107 AF16 A416 F9AF 18F3 D874 3E78 6F42 C449 77CA

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