sctp: fix stream->outcnt underflow on duplicate RECONF responses

commit 3faf13aff2 upstream.

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.

Fixes: 11ae76e67a ("sctp: implement receiver-side procedures for the Reconf Response Parameter")
Cc: stable@kernel.org
Reported-by: TencentOS Corvus AI <corvus@tencent.com>
Link: https://lore.kernel.org/netdev/20260730110225.37371-1-juny24602@gmail.com/
Suggested-by: Xin Long <lucien.xin@gmail.com>
Assisted-by: tencentos-corvus-ai:kimi-k3
Signed-off-by: Jun Yang <junvyyang@tencent.com>
Link: https://patch.msgid.link/20260824081832.98717-3-juny24602@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Jun Yang 2026-08-24 16:18:20 +08:00 • committed by Greg Kroah-Hartman
commit 59f61c39cb
2 changed files with 29 additions and 12 deletions