[PATCH net-next v11 0/6] tls: receive-path fixes and clean-ups

[PATCH net-next v11 0/6] tls: receive-path fixes and clean-ups

[Chuck Lever]

I'd like to encourage in-kernel kTLS consumers (NFSD, NVMe/TCP) to
coalesce on the use of read_sock. While auditing read_sock for that
purpose, Hannes and Sabrina flagged a few rough edges in the receive
paths.

This series is a set of clean-ups, not a performance series. Async
batch decryption and its submit/deliver scaffolding were dropped
during previous review: async_capable is always false for TLS 1.3,
the version NFSD and NVMe/TCP both require, so async-related
improvements were unreachable for the in-kernel consumers this
work targets.

A subsequent series will introduce infrastructure to support
KeyUpdate for in-kernel kTLS consumers, which need to handle TLS
Alert messages that trigger a tlshd upcall.

---
Changes since v11:
- 1/7 has been merged into net/main
- Rebased on net-next main (Fri May 22 18:40:51 2026 -0700)

Changes since v10:
- Move fixes to front of series
- Simplify loop termination in tls_sw_read_sock() (Sabrina)

Changes since v9:
- Recast cover letter: this is a clean-up series, not a
  performance series (Jakub, Sabrina)
- Rephrase subject to describe the refactor (Jakub)
- Split 2/5 into two patches separating the do/while
  loop-structure cleanup from the partial-consume fix (Sabrina)
- Continue the loop after a partial consume to match
  __tcp_read_sock() semantics, instead of exiting (Jakub)
- Drop kdoc on the internal function and rename
  tls_strp_msg_release() to tls_strp_msg_consume() (Jakub)
- Drop kdoc on tls_strp_check_rcv() and un-wrap the "Defer
  notification" comment (Jakub)
- Rename tls_strp_check_rcv() parameter wake to announce, and
  tls_rx_msg_ready() to tls_rx_msg_maybe_announce() (Jakub)
- Drop tls_rx_handoff(); fold the per-record path back into
  tls_rx_rec_done() and fire the deferred announce from
  tls_rx_reader_release() (Jakub)
- New patch: Preserve sk_err across recvmsg() when data has
  been copied, so a connection abort during sk_flush_backlog()
  surfaces on the next read instead of vanishing when the
  caller returns the bytes already accumulated

Changes since v8:
- Address review comments from sashiko
  - Patch 2: Requeue partially consumed skb to prevent leak
  - Patch 5: Re-check sk_err so RST during flush surfaces as
    -ECONNRESET instead of EOF
- Address review comments from gpt-5.5
  - Patch 4: Restore msg_ready early-return in tls_strp_check_rcv()
    so the queued strp_work doesn't double-wake the consumer
  - Patch 4: Add tls_strparser msg_announced bit so the recvmsg
    exit-point handoff doesn't re-fire saved_data_ready() for a
    record BH or the worker already announced (rx_list-only drain
    path)

Changes since v7:
- Rebased on net-next (v7.1-rc1)

Changes since v6:
- Rebased on net-next, v5's 1/6 was merged upstream

Changes since v5:
- Patch 6: Set released = true when sk_flush_backlog() returns
  true, so tls_strp_msg_load() knows the socket lock was
  released (Sabrina)
- Patch 6: Drop Fixes tag; submit bug fix separately via net
  if warranted (Sabrina)
- Patch 6: Note redundant flush on cold path in commit message
  (Sabrina)

Changes since v4:
- Drop batch async decryption and submit/deliver restructure:
  async_capable is always false for TLS 1.3, so the new code
  was unreachable for NFS and NVMe/TCP
- Purge async_hold directly in tls_decrypt_async_wait() and drop
  the tls_decrypt_async_drain() wrapper
- Merge tls_strp_check_rcv_quiet() into tls_strp_check_rcv() with
  a bool wake parameter; fix lost wakeup on the recvmsg exit path

Changes since v3:
- Clarify why tls_decrypt_async_drain() is separate from _wait()
- Fold tls_err_abort() into tls_rx_one_record(), drop tls_rx_decrypt_record()
- Move backlog flush into tls_rx_rec_wait() so all RX paths benefit

Changes since v2:
- Fix short read self tests

Changes since v1:
- Add C11 reference
- Extend data_ready reduction to recvmsg and splice
- Restructure read_sock and recvmsg using shared helpers

---
Changes in v11:
- EDITME: describe what is new in this series revision.
- EDITME: use bulletpoints and terse descriptions.
- Link to v10: https://patch.msgid.link/20260511-tls-read-sock-v10-0-279fc5015f0e@oracle.com

---
Chuck Lever (6):
      tls: Avoid evaluating freed skb in tls_sw_read_sock() loop
      tls: Re-present partially-consumed records in tls_sw_read_sock()
      tls: Move decrypt-failure abort into tls_rx_one_record()
      tls: Factor tls_strp_msg_consume() from tls_strp_msg_done()
      tls: Suppress spurious saved_data_ready on all receive paths
      tls: Flush backlog before waiting for a new record

 include/net/tls.h  |  5 +++++
 net/tls/tls.h      |  6 ++---
 net/tls/tls_main.c |  2 +-
 net/tls/tls_strp.c | 26 +++++++++++++++-------
 net/tls/tls_sw.c   | 64 ++++++++++++++++++++++++++++++++++++++----------------
 5 files changed, 72 insertions(+), 31 deletions(-)
---
base-commit: c0aa5f13826dcb035bec3d6b252e6b2020fa5f88
change-id: 20260317-tls-read-sock-a0022c9df265

Best regards,
--  
Chuck Lever <chuck.lever@oracle.com>

[PATCH net-next v11 1/6] tls: Avoid evaluating freed skb in tls_sw_read_sock() loop

[Chuck Lever]

From: Chuck Lever <chuck.lever@oracle.com>

tls_sw_read_sock() ends its receive loop with while (skb), but
the else branch in the body calls consume_skb(skb) before the
predicate is re-evaluated. A pointer becomes indeterminate when
the object it points to reaches end-of-lifetime (C2011 6.2.4p2),
and using an indeterminate value is undefined behavior (Annex
J.2). The pointer is not dereferenced today -- the predicate
either exits the loop or skb is overwritten at the top of the
next iteration -- but any future change that adds a dereference
between consume_skb() and the predicate would silently introduce
a use-after-free.

Replace the do/while form with an explicit for(;;) loop so
termination happens through a break statement rather than
predicate evaluation of a freed pointer.

Cc: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---
 net/tls/tls_sw.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c
index 964ebc268ee4..8e4e57721335 100644
--- a/net/tls/tls_sw.c
+++ b/net/tls/tls_sw.c
@@ -2383,7 +2383,7 @@ int tls_sw_read_sock(struct sock *sk, read_descriptor_t *desc,
 		goto read_sock_end;
 
 	decrypted = 0;
-	do {
+	for (;;) {
 		if (!skb_queue_empty(&ctx->rx_list)) {
 			skb = __skb_dequeue(&ctx->rx_list);
 			rxm = strp_msg(skb);
@@ -2435,9 +2435,9 @@ int tls_sw_read_sock(struct sock *sk, read_descriptor_t *desc,
 		} else {
 			consume_skb(skb);
 			if (!desc->count)
-				skb = NULL;
+				break;
 		}
-	} while (skb);
+	}
 
 read_sock_end:
 	tls_rx_reader_release(sk, ctx);

-- 
2.54.0

Re: [PATCH net-next v11 1/6] tls: Avoid evaluating freed skb in tls_sw_read_sock() loop

[Hannes Reinecke]

On 5/26/26 16:21, Chuck Lever wrote:
> From: Chuck Lever <chuck.lever@oracle.com>
> 
> tls_sw_read_sock() ends its receive loop with while (skb), but
> the else branch in the body calls consume_skb(skb) before the
> predicate is re-evaluated. A pointer becomes indeterminate when
> the object it points to reaches end-of-lifetime (C2011 6.2.4p2),
> and using an indeterminate value is undefined behavior (Annex
> J.2). The pointer is not dereferenced today -- the predicate
> either exits the loop or skb is overwritten at the top of the
> next iteration -- but any future change that adds a dereference
> between consume_skb() and the predicate would silently introduce
> a use-after-free.
> 
> Replace the do/while form with an explicit for(;;) loop so
> termination happens through a break statement rather than
> predicate evaluation of a freed pointer.
> 
> Cc: Sagi Grimberg <sagi@grimberg.me>
> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
> ---
>   net/tls/tls_sw.c | 6 +++---
>   1 file changed, 3 insertions(+), 3 deletions(-)
> 
Reviewed-by: Hannes Reinecke <hare@kernel.org>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                  Kernel Storage Architect
hare@suse.de                                +49 911 74053 688
SUSE Software Solutions GmbH, Frankenstr. 146, 90461 Nürnberg
HRB 36809 (AG Nürnberg), GF: I. Totev, A. McDonald, W. Knoblich

Re: [PATCH net-next v11 1/6] tls: Avoid evaluating freed skb in tls_sw_read_sock() loop

[Sabrina Dubroca]

2026-05-26, 10:21:31 -0400, Chuck Lever wrote:
> From: Chuck Lever <chuck.lever@oracle.com>
> 
> tls_sw_read_sock() ends its receive loop with while (skb), but
> the else branch in the body calls consume_skb(skb) before the
> predicate is re-evaluated. A pointer becomes indeterminate when
> the object it points to reaches end-of-lifetime (C2011 6.2.4p2),
> and using an indeterminate value is undefined behavior (Annex
> J.2). The pointer is not dereferenced today -- the predicate
> either exits the loop or skb is overwritten at the top of the
> next iteration -- but any future change that adds a dereference
> between consume_skb() and the predicate would silently introduce
> a use-after-free.
> 
> Replace the do/while form with an explicit for(;;) loop so
> termination happens through a break statement rather than
> predicate evaluation of a freed pointer.
> 
> Cc: Sagi Grimberg <sagi@grimberg.me>
> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
> ---
>  net/tls/tls_sw.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)

Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>

-- 
Sabrina

[PATCH net-next v11 2/6] tls: Re-present partially-consumed records in tls_sw_read_sock()

[Chuck Lever]

From: Chuck Lever <chuck.lever@oracle.com>

The tls_sw_read_sock() loop releases the current skb whether
read_actor() consumed the full record or only a prefix. When
the actor takes only part of the record and leaves desc->count
non-zero, the remainder is lost: skb is neither requeued nor
freed, and the next iteration overwrites it during dequeue or
tls_rx_rec_wait().

No mainline consumer reaches this path today. The only
in-tree TLS read_sock user is nvme/tcp, whose actor
nvme_tcp_recv_skb() loops until the input length is exhausted
and returns either the full length or a negative error.

The path becomes reachable with the upcoming NFSD svcsock
receive built on read_sock_cmsg. Its data actor,
svc_tcp_recv_actor(), parses an RPC fragment stream
incrementally and returns at fragment boundaries. When a TLS
record carries the tail of one RPC fragment plus the head of
the next, the actor returns fewer bytes than offered while
leaving desc->count non-zero, and without re-presentation the
trailing fragment header vanishes.

__tcp_read_sock() handles the equivalent case for plain TCP
by leaving the unread bytes available for the next iteration
to re-present, via sequence-number re-lookup. Adopt the same
loop-level behavior: when read_actor() consumes only part of
the record, update rxm->offset and rxm->full_len and requeue
the skb to the head of rx_list so the next iteration
re-presents the unread bytes. Switch the open-ended for-loop
to "while (desc->count)" so the partial- and full-consume
arms share a single exit check and read_actor() is not
re-invoked once desc->count is exhausted.

Cc: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---
 net/tls/tls_sw.c | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c
index 8e4e57721335..fd8d3c979368 100644
--- a/net/tls/tls_sw.c
+++ b/net/tls/tls_sw.c
@@ -2383,7 +2383,7 @@ int tls_sw_read_sock(struct sock *sk, read_descriptor_t *desc,
 		goto read_sock_end;
 
 	decrypted = 0;
-	for (;;) {
+	while (desc->count) {
 		if (!skb_queue_empty(&ctx->rx_list)) {
 			skb = __skb_dequeue(&ctx->rx_list);
 			rxm = strp_msg(skb);
@@ -2430,12 +2430,9 @@ int tls_sw_read_sock(struct sock *sk, read_descriptor_t *desc,
 		if (used < rxm->full_len) {
 			rxm->offset += used;
 			rxm->full_len -= used;
-			if (!desc->count)
-				goto read_sock_requeue;
+			__skb_queue_head(&ctx->rx_list, skb);
 		} else {
 			consume_skb(skb);
-			if (!desc->count)
-				break;
 		}
 	}
 

-- 
2.54.0

Re: [PATCH net-next v11 2/6] tls: Re-present partially-consumed records in tls_sw_read_sock()

[Hannes Reinecke]

On 5/26/26 16:21, Chuck Lever wrote:
> From: Chuck Lever <chuck.lever@oracle.com>
> 
> The tls_sw_read_sock() loop releases the current skb whether
> read_actor() consumed the full record or only a prefix. When
> the actor takes only part of the record and leaves desc->count
> non-zero, the remainder is lost: skb is neither requeued nor
> freed, and the next iteration overwrites it during dequeue or
> tls_rx_rec_wait().
> 
> No mainline consumer reaches this path today. The only
> in-tree TLS read_sock user is nvme/tcp, whose actor
> nvme_tcp_recv_skb() loops until the input length is exhausted
> and returns either the full length or a negative error.
> 
> The path becomes reachable with the upcoming NFSD svcsock
> receive built on read_sock_cmsg. Its data actor,
> svc_tcp_recv_actor(), parses an RPC fragment stream
> incrementally and returns at fragment boundaries. When a TLS
> record carries the tail of one RPC fragment plus the head of
> the next, the actor returns fewer bytes than offered while
> leaving desc->count non-zero, and without re-presentation the
> trailing fragment header vanishes.
> 
> __tcp_read_sock() handles the equivalent case for plain TCP
> by leaving the unread bytes available for the next iteration
> to re-present, via sequence-number re-lookup. Adopt the same
> loop-level behavior: when read_actor() consumes only part of
> the record, update rxm->offset and rxm->full_len and requeue
> the skb to the head of rx_list so the next iteration
> re-presents the unread bytes. Switch the open-ended for-loop
> to "while (desc->count)" so the partial- and full-consume
> arms share a single exit check and read_actor() is not
> re-invoked once desc->count is exhausted.
> 
> Cc: Sagi Grimberg <sagi@grimberg.me>
> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
> ---
>   net/tls/tls_sw.c | 7 ++-----
>   1 file changed, 2 insertions(+), 5 deletions(-)
> 
Reviewed-by: Hannes Reinecke <hare@kernel.org>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                  Kernel Storage Architect
hare@suse.de                                +49 911 74053 688
SUSE Software Solutions GmbH, Frankenstr. 146, 90461 Nürnberg
HRB 36809 (AG Nürnberg), GF: I. Totev, A. McDonald, W. Knoblich

Re: [PATCH net-next v11 2/6] tls: Re-present partially-consumed records in tls_sw_read_sock()

[Sabrina Dubroca]

2026-05-26, 10:21:32 -0400, Chuck Lever wrote:
> From: Chuck Lever <chuck.lever@oracle.com>
> 
> The tls_sw_read_sock() loop releases the current skb whether
> read_actor() consumed the full record or only a prefix. When
> the actor takes only part of the record and leaves desc->count
> non-zero, the remainder is lost: skb is neither requeued nor
> freed, and the next iteration overwrites it during dequeue or
> tls_rx_rec_wait().
> 
> No mainline consumer reaches this path today. The only
> in-tree TLS read_sock user is nvme/tcp, whose actor
> nvme_tcp_recv_skb() loops until the input length is exhausted
> and returns either the full length or a negative error.
> 
> The path becomes reachable with the upcoming NFSD svcsock
> receive built on read_sock_cmsg. Its data actor,
> svc_tcp_recv_actor(), parses an RPC fragment stream
> incrementally and returns at fragment boundaries. When a TLS
> record carries the tail of one RPC fragment plus the head of
> the next, the actor returns fewer bytes than offered while
> leaving desc->count non-zero, and without re-presentation the
> trailing fragment header vanishes.
> 
> __tcp_read_sock() handles the equivalent case for plain TCP
> by leaving the unread bytes available for the next iteration
> to re-present, via sequence-number re-lookup. Adopt the same
> loop-level behavior: when read_actor() consumes only part of
> the record, update rxm->offset and rxm->full_len and requeue
> the skb to the head of rx_list so the next iteration
> re-presents the unread bytes. Switch the open-ended for-loop
> to "while (desc->count)" so the partial- and full-consume
> arms share a single exit check and read_actor() is not
> re-invoked once desc->count is exhausted.
> 
> Cc: Sagi Grimberg <sagi@grimberg.me>
> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
> ---
>  net/tls/tls_sw.c | 7 ++-----
>  1 file changed, 2 insertions(+), 5 deletions(-)

Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>

-- 
Sabrina

[PATCH net-next v11 3/6] tls: Move decrypt-failure abort into tls_rx_one_record()

[Chuck Lever]

From: Chuck Lever <chuck.lever@oracle.com>

Three receive paths -- recvmsg, read_sock, and splice_read --
each follow tls_rx_one_record() with the same tls_err_abort()
call. Consolidate the abort into tls_rx_one_record() so the
decrypt-and-abort sequence lives in one place.

A tls_check_pending_rekey() failure after successful
decryption no longer triggers tls_err_abort(). That path
fires only when skb_copy_bits() fails on a valid skb,
which is not a realistic scenario.

Suggested-by: Sabrina Dubroca <sd@queasysnail.net>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---
 net/tls/tls_sw.c | 19 +++++++++----------
 1 file changed, 9 insertions(+), 10 deletions(-)

diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c
index fd8d3c979368..798f2535ddf7 100644
--- a/net/tls/tls_sw.c
+++ b/net/tls/tls_sw.c
@@ -1827,6 +1827,9 @@ static int tls_check_pending_rekey(struct sock *sk, struct tls_context *ctx,
 	return 0;
 }
 
+/* On decrypt failure the connection is aborted (sk_err set) before
+ * returning a negative errno.
+ */
 static int tls_rx_one_record(struct sock *sk, struct msghdr *msg,
 			     struct tls_decrypt_arg *darg)
 {
@@ -1838,8 +1841,10 @@ static int tls_rx_one_record(struct sock *sk, struct msghdr *msg,
 	err = tls_decrypt_device(sk, msg, tls_ctx, darg);
 	if (!err)
 		err = tls_decrypt_sw(sk, tls_ctx, msg, darg);
-	if (err < 0)
+	if (err < 0) {
+		tls_err_abort(sk, -EBADMSG);
 		return err;
+	}
 
 	rxm = strp_msg(darg->skb);
 	rxm->offset += prot->prepend_size;
@@ -2150,10 +2155,8 @@ int tls_sw_recvmsg(struct sock *sk,
 			darg.async = false;
 
 		err = tls_rx_one_record(sk, msg, &darg);
-		if (err < 0) {
-			tls_err_abort(sk, -EBADMSG);
+		if (err < 0)
 			goto recv_end;
-		}
 
 		async |= darg.async;
 
@@ -2312,10 +2315,8 @@ ssize_t tls_sw_splice_read(struct socket *sock,  loff_t *ppos,
 		memset(&darg.inargs, 0, sizeof(darg.inargs));
 
 		err = tls_rx_one_record(sk, NULL, &darg);
-		if (err < 0) {
-			tls_err_abort(sk, -EBADMSG);
+		if (err < 0)
 			goto splice_read_end;
-		}
 
 		tls_rx_rec_done(ctx);
 		skb = darg.skb;
@@ -2398,10 +2399,8 @@ int tls_sw_read_sock(struct sock *sk, read_descriptor_t *desc,
 			memset(&darg.inargs, 0, sizeof(darg.inargs));
 
 			err = tls_rx_one_record(sk, NULL, &darg);
-			if (err < 0) {
-				tls_err_abort(sk, -EBADMSG);
+			if (err < 0)
 				goto read_sock_end;
-			}
 
 			released = tls_read_flush_backlog(sk, prot, INT_MAX,
 							  0, decrypted,

-- 
2.54.0

[PATCH net-next v11 4/6] tls: Factor tls_strp_msg_consume() from tls_strp_msg_done()

[Chuck Lever]

From: Chuck Lever <chuck.lever@oracle.com>

tls_strp_msg_done() conflates releasing the current record with
checking for the next one via tls_strp_check_rcv(). A subsequent
patch needs to release a record without immediately triggering
that check, so the release step is separated into
tls_strp_msg_consume(). tls_strp_msg_done() is preserved as a
wrapper for existing callers.

Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---
 net/tls/tls.h      |  1 +
 net/tls/tls_strp.c | 11 ++++++++++-
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/net/tls/tls.h b/net/tls/tls.h
index 12f44cb649c9..cb0091e03f41 100644
--- a/net/tls/tls.h
+++ b/net/tls/tls.h
@@ -194,6 +194,7 @@ int tls_strp_init(struct tls_strparser *strp, struct sock *sk);
 void tls_strp_data_ready(struct tls_strparser *strp);
 
 void tls_strp_check_rcv(struct tls_strparser *strp);
+void tls_strp_msg_consume(struct tls_strparser *strp);
 void tls_strp_msg_done(struct tls_strparser *strp);
 
 int tls_rx_msg_size(struct tls_strparser *strp, struct sk_buff *skb);
diff --git a/net/tls/tls_strp.c b/net/tls/tls_strp.c
index c72e88317627..e7aaee6efe6e 100644
--- a/net/tls/tls_strp.c
+++ b/net/tls/tls_strp.c
@@ -581,7 +581,12 @@ static void tls_strp_work(struct work_struct *w)
 	release_sock(strp->sk);
 }
 
-void tls_strp_msg_done(struct tls_strparser *strp)
+/* Release the current record without triggering a check for the
+ * next record. Callers must invoke tls_strp_check_rcv() before
+ * releasing the socket lock, or queued data will stall until the
+ * next tls_strp_data_ready() event.
+ */
+void tls_strp_msg_consume(struct tls_strparser *strp)
 {
 	WARN_ON(!strp->stm.full_len);
 
@@ -592,7 +597,11 @@ void tls_strp_msg_done(struct tls_strparser *strp)
 
 	WRITE_ONCE(strp->msg_ready, 0);
 	memset(&strp->stm, 0, sizeof(strp->stm));
+}
 
+void tls_strp_msg_done(struct tls_strparser *strp)
+{
+	tls_strp_msg_consume(strp);
 	tls_strp_check_rcv(strp);
 }
 

-- 
2.54.0

Re: [PATCH net-next v11 4/6] tls: Factor tls_strp_msg_consume() from tls_strp_msg_done()

[Sabrina Dubroca]

2026-05-26, 10:21:34 -0400, Chuck Lever wrote:
> From: Chuck Lever <chuck.lever@oracle.com>
> 
> tls_strp_msg_done() conflates releasing the current record with
> checking for the next one via tls_strp_check_rcv(). A subsequent
> patch needs to release a record without immediately triggering
> that check, so the release step is separated into
> tls_strp_msg_consume(). tls_strp_msg_done() is preserved as a
> wrapper for existing callers.
> 
> Reviewed-by: Hannes Reinecke <hare@suse.de>
> Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
> ---
>  net/tls/tls.h      |  1 +
>  net/tls/tls_strp.c | 11 ++++++++++-
>  2 files changed, 11 insertions(+), 1 deletion(-)

Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>

-- 
Sabrina

[PATCH net-next v11 5/6] tls: Suppress spurious saved_data_ready on all receive paths

[Chuck Lever]

From: Chuck Lever <chuck.lever@oracle.com>

Each record release via tls_strp_msg_done() triggered
tls_strp_check_rcv(), which called tls_rx_msg_ready() and
fired saved_data_ready(). During a multi-record receive, the
first N-1 wakeups are pure overhead: the caller is already
running and will pick up subsequent records on the next loop
iteration. The recvmsg and splice_read paths share this waste.

Suppress per-record notifications and emit a single one on
reader exit. tls_rx_rec_done() releases the current record
and parses the next without announcing; tls_strp_check_rcv()
gains a bool announce parameter so callers can request the
quiet form. tls_rx_reader_release() fires the deferred
announce on exit through tls_rx_msg_maybe_announce(), an
idempotent helper that calls saved_data_ready() only when a
record is parsed and has not yet been announced.

To keep the final notification idempotent against records that
the BH or the worker has already announced, tls_strparser gains
a msg_announced bit. tls_rx_msg_maybe_announce() sets the bit
when firing saved_data_ready(); the bit is cleared whenever
the parsed record is wiped, by tls_strp_msg_consume() on
consumption or by tls_strp_msg_load() when the lower socket
loses bytes from under the parse. A second call for the same
parsed record -- as when recvmsg() satisfies the request from
ctx->rx_list without touching the strparser -- becomes a
no-op.

With no remaining callers, tls_strp_msg_done() is removed.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---
 include/net/tls.h  |  5 +++++
 net/tls/tls.h      |  5 ++---
 net/tls/tls_main.c |  2 +-
 net/tls/tls_strp.c | 23 ++++++++++++-----------
 net/tls/tls_sw.c   | 27 ++++++++++++++++++++++++---
 5 files changed, 44 insertions(+), 18 deletions(-)

diff --git a/include/net/tls.h b/include/net/tls.h
index ebd2550280ae..3811943288b3 100644
--- a/include/net/tls.h
+++ b/include/net/tls.h
@@ -111,11 +111,16 @@ struct tls_sw_context_tx {
 struct tls_strparser {
 	struct sock *sk;
 
+	/* Bitfield word and msg_ready are serialized by the lower
+	 * socket lock; BH and worker contexts both acquire it.
+	 */
 	u32 mark : 8;
 	u32 stopped : 1;
 	u32 copy_mode : 1;
 	u32 mixed_decrypted : 1;
 
+	u32 msg_announced : 1;
+
 	bool msg_ready;
 
 	struct strp_msg stm;
diff --git a/net/tls/tls.h b/net/tls/tls.h
index cb0091e03f41..60a37bdaaa25 100644
--- a/net/tls/tls.h
+++ b/net/tls/tls.h
@@ -193,12 +193,11 @@ void tls_strp_stop(struct tls_strparser *strp);
 int tls_strp_init(struct tls_strparser *strp, struct sock *sk);
 void tls_strp_data_ready(struct tls_strparser *strp);
 
-void tls_strp_check_rcv(struct tls_strparser *strp);
+void tls_strp_check_rcv(struct tls_strparser *strp, bool announce);
 void tls_strp_msg_consume(struct tls_strparser *strp);
-void tls_strp_msg_done(struct tls_strparser *strp);
 
 int tls_rx_msg_size(struct tls_strparser *strp, struct sk_buff *skb);
-void tls_rx_msg_ready(struct tls_strparser *strp);
+void tls_rx_msg_maybe_announce(struct tls_strparser *strp);
 
 bool tls_strp_msg_load(struct tls_strparser *strp, bool force_refresh);
 int tls_strp_msg_cow(struct tls_sw_context_rx *ctx);
diff --git a/net/tls/tls_main.c b/net/tls/tls_main.c
index fd39acf41a61..c10a3fd7fc17 100644
--- a/net/tls/tls_main.c
+++ b/net/tls/tls_main.c
@@ -769,7 +769,7 @@ static int do_tls_setsockopt_conf(struct sock *sk, sockptr_t optval,
 	} else {
 		struct tls_sw_context_rx *rx_ctx = tls_sw_ctx_rx(ctx);
 
-		tls_strp_check_rcv(&rx_ctx->strp);
+		tls_strp_check_rcv(&rx_ctx->strp, true);
 	}
 	return 0;
 
diff --git a/net/tls/tls_strp.c b/net/tls/tls_strp.c
index e7aaee6efe6e..61b10c697ecc 100644
--- a/net/tls/tls_strp.c
+++ b/net/tls/tls_strp.c
@@ -368,7 +368,6 @@ static int tls_strp_copyin(read_descriptor_t *desc, struct sk_buff *in_skb,
 		desc->count = 0;
 
 		WRITE_ONCE(strp->msg_ready, 1);
-		tls_rx_msg_ready(strp);
 	}
 
 	return ret;
@@ -492,6 +491,7 @@ bool tls_strp_msg_load(struct tls_strparser *strp, bool force_refresh)
 	if (!strp->copy_mode && force_refresh) {
 		if (unlikely(tcp_inq(strp->sk) < strp->stm.full_len)) {
 			WRITE_ONCE(strp->msg_ready, 0);
+			strp->msg_announced = 0;
 			memset(&strp->stm, 0, sizeof(strp->stm));
 			return false;
 		}
@@ -539,18 +539,24 @@ static int tls_strp_read_sock(struct tls_strparser *strp)
 		return tls_strp_read_copy(strp, false);
 
 	WRITE_ONCE(strp->msg_ready, 1);
-	tls_rx_msg_ready(strp);
 
 	return 0;
 }
 
-void tls_strp_check_rcv(struct tls_strparser *strp)
+/* Parse queued data. When @announce is true and parsing produces a
+ * newly-ready record, fire the consumer notification. Callers that
+ * need to notify a waiter about a record parsed by another path
+ * should invoke tls_rx_msg_maybe_announce() directly.
+ */
+void tls_strp_check_rcv(struct tls_strparser *strp, bool announce)
 {
 	if (unlikely(strp->stopped) || strp->msg_ready)
 		return;
 
 	if (tls_strp_read_sock(strp) == -ENOMEM)
 		queue_work(tls_strp_wq, &strp->work);
+	else if (announce && strp->msg_ready)
+		tls_rx_msg_maybe_announce(strp);
 }
 
 /* Lower sock lock held */
@@ -568,7 +574,7 @@ void tls_strp_data_ready(struct tls_strparser *strp)
 		return;
 	}
 
-	tls_strp_check_rcv(strp);
+	tls_strp_check_rcv(strp, true);
 }
 
 static void tls_strp_work(struct work_struct *w)
@@ -577,7 +583,7 @@ static void tls_strp_work(struct work_struct *w)
 		container_of(w, struct tls_strparser, work);
 
 	lock_sock(strp->sk);
-	tls_strp_check_rcv(strp);
+	tls_strp_check_rcv(strp, true);
 	release_sock(strp->sk);
 }
 
@@ -596,15 +602,10 @@ void tls_strp_msg_consume(struct tls_strparser *strp)
 		tls_strp_flush_anchor_copy(strp);
 
 	WRITE_ONCE(strp->msg_ready, 0);
+	strp->msg_announced = 0;
 	memset(&strp->stm, 0, sizeof(strp->stm));
 }
 
-void tls_strp_msg_done(struct tls_strparser *strp)
-{
-	tls_strp_msg_consume(strp);
-	tls_strp_check_rcv(strp);
-}
-
 void tls_strp_stop(struct tls_strparser *strp)
 {
 	strp->stopped = 1;
diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c
index 798f2535ddf7..df4cdf11f784 100644
--- a/net/tls/tls_sw.c
+++ b/net/tls/tls_sw.c
@@ -1401,7 +1401,10 @@ tls_rx_rec_wait(struct sock *sk, struct sk_psock *psock, bool nonblock,
 			return ret;
 
 		if (!skb_queue_empty(&sk->sk_receive_queue)) {
-			tls_strp_check_rcv(&ctx->strp);
+			/* Defer notification to the exit point; this thread
+			 * will consume the record directly.
+			 */
+			tls_strp_check_rcv(&ctx->strp, false);
 			if (tls_strp_msg_ready(ctx))
 				break;
 		}
@@ -1887,9 +1890,13 @@ static int tls_record_content_type(struct msghdr *msg, struct tls_msg *tlm,
 	return 1;
 }
 
+/* The deferred announce is fired once on reader exit by
+ * tls_rx_reader_release().
+ */
 static void tls_rx_rec_done(struct tls_sw_context_rx *ctx)
 {
-	tls_strp_msg_done(&ctx->strp);
+	tls_strp_msg_consume(&ctx->strp);
+	tls_strp_check_rcv(&ctx->strp, false);
 }
 
 /* This function traverses the rx_list in tls receive context to copies the
@@ -2044,6 +2051,12 @@ static int tls_rx_reader_lock(struct sock *sk, struct tls_sw_context_rx *ctx,
 
 static void tls_rx_reader_release(struct sock *sk, struct tls_sw_context_rx *ctx)
 {
+	/* Fire any deferred announce once per reader so that a record
+	 * parsed but not yet announced becomes visible to the next
+	 * reader. The call is idempotent through msg_announced.
+	 */
+	tls_rx_msg_maybe_announce(&ctx->strp);
+
 	if (unlikely(ctx->reader_contended)) {
 		if (wq_has_sleeper(&ctx->wq))
 			wake_up(&ctx->wq);
@@ -2520,10 +2533,18 @@ int tls_rx_msg_size(struct tls_strparser *strp, struct sk_buff *skb)
 	return ret;
 }
 
-void tls_rx_msg_ready(struct tls_strparser *strp)
+/* Fire saved_data_ready() at most once per parsed record. The
+ * msg_announced bit is cleared by tls_strp_msg_consume() when the
+ * record is consumed, arming the next announcement.
+ */
+void tls_rx_msg_maybe_announce(struct tls_strparser *strp)
 {
 	struct tls_sw_context_rx *ctx;
 
+	if (!READ_ONCE(strp->msg_ready) || strp->msg_announced)
+		return;
+	strp->msg_announced = 1;
+
 	ctx = container_of(strp, struct tls_sw_context_rx, strp);
 	ctx->saved_data_ready(strp->sk);
 }

-- 
2.54.0

Re: [PATCH net-next v11 5/6] tls: Suppress spurious saved_data_ready on all receive paths

[Hannes Reinecke]

On 5/26/26 16:21, Chuck Lever wrote:
> From: Chuck Lever <chuck.lever@oracle.com>
> 
> Each record release via tls_strp_msg_done() triggered
> tls_strp_check_rcv(), which called tls_rx_msg_ready() and
> fired saved_data_ready(). During a multi-record receive, the
> first N-1 wakeups are pure overhead: the caller is already
> running and will pick up subsequent records on the next loop
> iteration. The recvmsg and splice_read paths share this waste.
> 
> Suppress per-record notifications and emit a single one on
> reader exit. tls_rx_rec_done() releases the current record
> and parses the next without announcing; tls_strp_check_rcv()
> gains a bool announce parameter so callers can request the
> quiet form. tls_rx_reader_release() fires the deferred
> announce on exit through tls_rx_msg_maybe_announce(), an
> idempotent helper that calls saved_data_ready() only when a
> record is parsed and has not yet been announced.
> 
> To keep the final notification idempotent against records that
> the BH or the worker has already announced, tls_strparser gains
> a msg_announced bit. tls_rx_msg_maybe_announce() sets the bit
> when firing saved_data_ready(); the bit is cleared whenever
> the parsed record is wiped, by tls_strp_msg_consume() on
> consumption or by tls_strp_msg_load() when the lower socket
> loses bytes from under the parse. A second call for the same
> parsed record -- as when recvmsg() satisfies the request from
> ctx->rx_list without touching the strparser -- becomes a
> no-op.
> 
> With no remaining callers, tls_strp_msg_done() is removed.
> 
> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
> ---
>   include/net/tls.h  |  5 +++++
>   net/tls/tls.h      |  5 ++---
>   net/tls/tls_main.c |  2 +-
>   net/tls/tls_strp.c | 23 ++++++++++++-----------
>   net/tls/tls_sw.c   | 27 ++++++++++++++++++++++++---
>   5 files changed, 44 insertions(+), 18 deletions(-)
> 
Reviewed-by: Hannes Reinecke <hare@kernel.org>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                  Kernel Storage Architect
hare@suse.de                                +49 911 74053 688
SUSE Software Solutions GmbH, Frankenstr. 146, 90461 Nürnberg
HRB 36809 (AG Nürnberg), GF: I. Totev, A. McDonald, W. Knoblich

[PATCH net-next v11 6/6] tls: Flush backlog before waiting for a new record

[Chuck Lever]

From: Chuck Lever <chuck.lever@oracle.com>

While lock_sock is held, incoming TCP segments land on
sk->sk_backlog rather than sk->sk_receive_queue.
tls_rx_rec_wait() inspects only sk_receive_queue, so backlog
data remains invisible. For non-blocking callers (read_sock,
and recvmsg or splice_read with MSG_DONTWAIT) this causes a
spurious -EAGAIN. For blocking callers it forces an
unnecessary sleep/wakeup cycle.

Flush the backlog inside tls_rx_rec_wait() before checking
sk_receive_queue so the strparser can parse newly-arrived
segments immediately. On the next loop iteration
tls_read_flush_backlog() may redundantly flush, but this
path is cold and the cost is negligible.

Backlog processing can run tcp_reset(), which calls
tcp_done_with_error() to set sk->sk_err = ECONNRESET and then
tcp_done() to set sk->sk_shutdown = SHUTDOWN_MASK. The pre-existing
top-of-loop sk_err check already ran before the flush, so the
freshly-set error would be masked by the next-line sk_shutdown test
returning 0 (EOF). Re-check sk_err immediately before the sk_shutdown
test so a connection abort surfaces as -ECONNRESET rather than a clean
EOF.

Suggested-by: Sabrina Dubroca <sd@queasysnail.net>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---
 net/tls/tls_sw.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c
index df4cdf11f784..d2f31623511a 100644
--- a/net/tls/tls_sw.c
+++ b/net/tls/tls_sw.c
@@ -1400,6 +1400,8 @@ tls_rx_rec_wait(struct sock *sk, struct sk_psock *psock, bool nonblock,
 		if (ret < 0)
 			return ret;
 
+		if (sk_flush_backlog(sk))
+			released = true;
 		if (!skb_queue_empty(&sk->sk_receive_queue)) {
 			/* Defer notification to the exit point; this thread
 			 * will consume the record directly.
@@ -1409,6 +1411,13 @@ tls_rx_rec_wait(struct sock *sk, struct sk_psock *psock, bool nonblock,
 				break;
 		}
 
+		/* sk_flush_backlog() can run tcp_reset(), which sets
+		 * sk_err and then sk_shutdown via tcp_done(). Recheck
+		 * sk_err here so a connection abort surfaces as the
+		 * actual error rather than a clean EOF.
+		 */
+		if (sk->sk_err)
+			return -READ_ONCE(sk->sk_err);
 		if (sk->sk_shutdown & RCV_SHUTDOWN)
 			return 0;
 

-- 
2.54.0