In the Linux kernel, the following vulnerability has been resolved: sctp: fix stream->outcnt underflow on duplicate RECONF responses A cached RECONF chunk may contain more than one request parameter. A duplicate response can therefore find and process the same ADD_OUT request again while another parameter is still outstanding, rolling back outcnt twice and possibly underflowing it. Track outstanding request types as bits and clear each bit after its first response. Later responses for the same request are then ignored.
https://git.kernel.org/stable/c/d02a5794c3deedcb8476d017fcee2b7aaedab2e1
https://git.kernel.org/stable/c/8320cbd81bc21a1ca6ebdf70ad610ebc5ef1bd68
https://git.kernel.org/stable/c/3faf13aff243ca9f78d08b1a2956ef5a6fc77b6e
https://git.kernel.org/stable/c/2d867663c563e8009257b9edf9c8ec75d9bbf19a