[PATCH net-next v5] sctp: auth: discard auth_chunk when skb_clone fails
flat view
STALE81d
LANDED
From: luoqing <hidden>
Date: 2026-07-23 06:11:44
Also in:
linux-sctp, lkml
Subsystem:
networking [general], sctp protocol, the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Marcelo Ricardo Leitner, Xin Long, Linus Torvalds
Landed in mainline as 9ae7ed101cf2 on 2026-07-29.
From: Qing Luo <redacted> When processing AUTH + COOKIE-ECHO packets, if skb_clone() fails due to memory pressure, chunk->auth_chunk is NULL. The original code still sets chunk->auth = 1 and continues, leaving the COOKIE-ECHO to be processed without a valid auth_chunk for deferred verification. Discard the AUTH chunk early via pdiscard when skb_clone() fails, so that the receive loop can continue processing remaining chunks in the inqueue instead of stalling the entire packet. Signed-off-by: Qing Luo <redacted> --- net/sctp/associola.c | 4 ++++ net/sctp/endpointola.c | 4 ++++ 2 files changed, 8 insertions(+)
diff --git a/net/sctp/associola.c b/net/sctp/associola.c
index 62d3cc155809..a5f2835dbe0f 100644
--- a/net/sctp/associola.c
+++ b/net/sctp/associola.c@@ -999,6 +999,10 @@ static void sctp_assoc_bh_rcv(struct work_struct *work) if (next_hdr->type == SCTP_CID_COOKIE_ECHO) { chunk->auth_chunk = skb_clone(chunk->skb, GFP_ATOMIC); + if (!chunk->auth_chunk) { + chunk->pdiscard = 1; + continue; + } chunk->auth = 1; continue; }
diff --git a/net/sctp/endpointola.c b/net/sctp/endpointola.c
index dfb1719275db..a15b599b20b7 100644
--- a/net/sctp/endpointola.c
+++ b/net/sctp/endpointola.c@@ -368,6 +368,10 @@ static void sctp_endpoint_bh_rcv(struct work_struct *work) if (next_hdr->type == SCTP_CID_COOKIE_ECHO) { chunk->auth_chunk = skb_clone(chunk->skb, GFP_ATOMIC); + if (!chunk->auth_chunk) { + chunk->pdiscard = 1; + continue; + } chunk->auth = 1; continue; }
--
2.25.1
Thank you for the review and the suggestion.
I agree that using chunk->pdiscard = 1; continue; is better than break;. It avoids stalling the entire inqueue under memory pressure and follows the existing discard convention in SCTP. I will update the patch accordingly.
Thanks,
luoqing