5.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jun Yang commit 3faf13aff243ca9f78d08b1a2956ef5a6fc77b6e 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: 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 Signed-off-by: Greg Kroah-Hartman --- include/net/sctp/structs.h | 2 +- net/sctp/stream.c | 39 ++++++++++++++++++++++++++++----------- 2 files changed, 29 insertions(+), 12 deletions(-) --- a/include/net/sctp/structs.h +++ b/include/net/sctp/structs.h @@ -2062,7 +2062,7 @@ 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 */ --- 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_ 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_as 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_as 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 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 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 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 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 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 nums, 0, GFP_ATOMIC); } - asoc->strreset_outstanding--; + SCTP_STRRESET_CLEAR(asoc, req->type); asoc->strreset_outseq++; /* remove everything for this reconf request */