From 63f44178f0a0f86060c9b576d6efab8a3ffa403e Mon Sep 17 00:00:00 2001 From: Jun Yang Date: Mon, 24 Aug 2026 16:18:19 +0800 Subject: sctp: distinguish sequence zero from wildcard in reconf lookup Zero is a valid response sequence after strreset_outseq wraps, but sctp_chunk_lookup_strreset_param() currently treats it as a wildcard. Add match_seq so response lookups match zero exactly while the one type-only lookup can still ignore the sequence. Fixes: 50a41591f110 ("sctp: implement receiver-side procedures for the Add Outgoing Streams Request Parameter") Cc: stable@kernel.org Suggested-by: Simon Horman Acked-by: Xin Long Signed-off-by: Jun Yang Link: https://patch.msgid.link/20260824081832.98717-2-juny24602@gmail.com Signed-off-by: Paolo Abeni --- net/sctp/stream.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/net/sctp/stream.c b/net/sctp/stream.c index 2012f61e250e..285cbebd899e 100644 --- a/net/sctp/stream.c +++ b/net/sctp/stream.c @@ -482,7 +482,7 @@ out: static struct sctp_paramhdr *sctp_chunk_lookup_strreset_param( struct sctp_association *asoc, __be32 resp_seq, - __be16 type) + __be16 type, bool match_seq) { struct sctp_chunk *chunk = asoc->strreset_chunk; struct sctp_reconf_chunk *hdr; @@ -499,7 +499,7 @@ static struct sctp_paramhdr *sctp_chunk_lookup_strreset_param( */ struct sctp_strreset_tsnreq *req = param.v; - if ((!resp_seq || req->request_seq == resp_seq) && + if ((!match_seq || req->request_seq == resp_seq) && (!type || type == req->param_hdr.type)) return param.v; } @@ -564,7 +564,7 @@ struct sctp_chunk *sctp_process_strreset_outreq( if (asoc->strreset_chunk) { if (!sctp_chunk_lookup_strreset_param( asoc, outreq->response_seq, - SCTP_PARAM_RESET_IN_REQUEST)) { + SCTP_PARAM_RESET_IN_REQUEST, true)) { /* same process with outstanding isn't 0 */ result = SCTP_STRRESET_ERR_IN_PROGRESS; goto out; @@ -816,7 +816,7 @@ struct sctp_chunk *sctp_process_strreset_addstrm_out( if (asoc->strreset_chunk) { if (!sctp_chunk_lookup_strreset_param( - asoc, 0, SCTP_PARAM_RESET_ADD_IN_STREAMS)) { + asoc, 0, SCTP_PARAM_RESET_ADD_IN_STREAMS, false)) { /* same process with outstanding isn't 0 */ result = SCTP_STRRESET_ERR_IN_PROGRESS; goto out; @@ -927,7 +927,8 @@ struct sctp_chunk *sctp_process_strreset_resp( struct sctp_paramhdr *req; __u32 result; - req = sctp_chunk_lookup_strreset_param(asoc, resp->response_seq, 0); + req = sctp_chunk_lookup_strreset_param(asoc, resp->response_seq, 0, + true); if (!req) return NULL; -- cgit v1.2.3 From 3faf13aff243ca9f78d08b1a2956ef5a6fc77b6e Mon Sep 17 00:00:00 2001 From: Jun Yang Date: Mon, 24 Aug 2026 16:18:20 +0800 Subject: 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. Fixes: 11ae76e67a17 ("sctp: implement receiver-side procedures for the Reconf Response Parameter") Cc: stable@kernel.org Reported-by: TencentOS Corvus AI Link: https://lore.kernel.org/netdev/20260730110225.37371-1-juny24602@gmail.com/ Suggested-by: Xin Long Assisted-by: tencentos-corvus-ai:kimi-k3 Signed-off-by: Jun Yang Link: https://patch.msgid.link/20260824081832.98717-3-juny24602@gmail.com Signed-off-by: Paolo Abeni --- include/net/sctp/structs.h | 2 +- net/sctp/stream.c | 39 ++++++++++++++++++++++++++++----------- 2 files changed, 29 insertions(+), 12 deletions(-) diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h index cccc662561aa..b21f23b736fd 100644 --- a/include/net/sctp/structs.h +++ b/include/net/sctp/structs.h @@ -2057,7 +2057,7 @@ struct sctp_association { force_delay:1; __u8 strreset_enable; - __u8 strreset_outstanding; /* request param count on the fly */ + __u8 strreset_outstanding; /* request param bitmask on the fly */ __u32 strreset_outseq; /* Update after receiving response */ __u32 strreset_inseq; /* Update after receiving request */ diff --git a/net/sctp/stream.c b/net/sctp/stream.c index 285cbebd899e..e4354d58f20b 100644 --- a/net/sctp/stream.c +++ b/net/sctp/stream.c @@ -22,6 +22,15 @@ #include #include +#define SCTP_STRRESET_MASK(type) \ + BIT(ntohs(type) - ntohs(SCTP_PARAM_RESET_OUT_REQUEST)) +#define SCTP_STRRESET_TEST(asoc, type) \ + ((asoc)->strreset_outstanding & SCTP_STRRESET_MASK(type)) +#define SCTP_STRRESET_SET(asoc, type) \ + ((asoc)->strreset_outstanding |= SCTP_STRRESET_MASK(type)) +#define SCTP_STRRESET_CLEAR(asoc, type) \ + ((asoc)->strreset_outstanding &= ~SCTP_STRRESET_MASK(type)) + static void sctp_stream_shrink_out(struct sctp_stream *stream, __u16 outcnt) { struct sctp_association *asoc; @@ -372,7 +381,10 @@ int sctp_send_reset_streams(struct sctp_association *asoc, goto out; } - asoc->strreset_outstanding = out + in; + if (out) + SCTP_STRRESET_SET(asoc, SCTP_PARAM_RESET_OUT_REQUEST); + if (in) + SCTP_STRRESET_SET(asoc, SCTP_PARAM_RESET_IN_REQUEST); out: return retval; @@ -417,7 +429,7 @@ int sctp_send_reset_assoc(struct sctp_association *asoc) return retval; } - asoc->strreset_outstanding = 1; + SCTP_STRRESET_SET(asoc, SCTP_PARAM_RESET_TSN_REQUEST); return 0; } @@ -474,7 +486,10 @@ int sctp_send_add_streams(struct sctp_association *asoc, goto out; } - asoc->strreset_outstanding = !!out + !!in; + if (out) + SCTP_STRRESET_SET(asoc, SCTP_PARAM_RESET_ADD_OUT_STREAMS); + if (in) + SCTP_STRRESET_SET(asoc, SCTP_PARAM_RESET_ADD_IN_STREAMS); out: return retval; @@ -564,13 +579,14 @@ struct sctp_chunk *sctp_process_strreset_outreq( if (asoc->strreset_chunk) { if (!sctp_chunk_lookup_strreset_param( asoc, outreq->response_seq, - SCTP_PARAM_RESET_IN_REQUEST, true)) { + SCTP_PARAM_RESET_IN_REQUEST, true) || + !SCTP_STRRESET_TEST(asoc, SCTP_PARAM_RESET_IN_REQUEST)) { /* same process with outstanding isn't 0 */ result = SCTP_STRRESET_ERR_IN_PROGRESS; goto out; } - asoc->strreset_outstanding--; + SCTP_STRRESET_CLEAR(asoc, SCTP_PARAM_RESET_IN_REQUEST); asoc->strreset_outseq++; if (!asoc->strreset_outstanding) { @@ -669,7 +685,7 @@ struct sctp_chunk *sctp_process_strreset_inreq( SCTP_SO(stream, i)->state = SCTP_STREAM_CLOSED; asoc->strreset_chunk = chunk; - asoc->strreset_outstanding = 1; + SCTP_STRRESET_SET(asoc, SCTP_PARAM_RESET_OUT_REQUEST); sctp_chunk_hold(asoc->strreset_chunk); result = SCTP_STRRESET_PERFORMED; @@ -816,13 +832,14 @@ struct sctp_chunk *sctp_process_strreset_addstrm_out( if (asoc->strreset_chunk) { if (!sctp_chunk_lookup_strreset_param( - asoc, 0, SCTP_PARAM_RESET_ADD_IN_STREAMS, false)) { + asoc, 0, SCTP_PARAM_RESET_ADD_IN_STREAMS, false) || + !SCTP_STRRESET_TEST(asoc, SCTP_PARAM_RESET_ADD_IN_STREAMS)) { /* same process with outstanding isn't 0 */ result = SCTP_STRRESET_ERR_IN_PROGRESS; goto out; } - asoc->strreset_outstanding--; + SCTP_STRRESET_CLEAR(asoc, SCTP_PARAM_RESET_ADD_IN_STREAMS); asoc->strreset_outseq++; if (!asoc->strreset_outstanding) { @@ -899,7 +916,7 @@ struct sctp_chunk *sctp_process_strreset_addstrm_in( goto out; asoc->strreset_chunk = chunk; - asoc->strreset_outstanding = 1; + SCTP_STRRESET_SET(asoc, SCTP_PARAM_RESET_ADD_OUT_STREAMS); sctp_chunk_hold(asoc->strreset_chunk); stream->outcnt = outcnt; @@ -929,7 +946,7 @@ struct sctp_chunk *sctp_process_strreset_resp( req = sctp_chunk_lookup_strreset_param(asoc, resp->response_seq, 0, true); - if (!req) + if (!req || !SCTP_STRRESET_TEST(asoc, req->type)) return NULL; result = ntohl(resp->result); @@ -1079,7 +1096,7 @@ struct sctp_chunk *sctp_process_strreset_resp( nums, 0, GFP_ATOMIC); } - asoc->strreset_outstanding--; + SCTP_STRRESET_CLEAR(asoc, req->type); asoc->strreset_outseq++; /* remove everything for this reconf request */ -- cgit v1.2.3