This is a note to let you know that I've just added the patch titled
net: tls: handle backlogging of crypto requests
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
net-tls-handle-backlogging-of-crypto-requests.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 8590541473188741055d27b955db0777569438e3 Mon Sep 17 00:00:00 2001
From: Jakub Kicinski <kuba@xxxxxxxxxx>
Date: Tue, 6 Feb 2024 17:18:21 -0800
Subject: net: tls: handle backlogging of crypto requests
From: Jakub Kicinski <kuba@xxxxxxxxxx>
commit 8590541473188741055d27b955db0777569438e3 upstream.
Since we're setting the CRYPTO_TFM_REQ_MAY_BACKLOG flag on our
requests to the crypto API, crypto_aead_{encrypt,decrypt} can return
-EBUSY instead of -EINPROGRESS in valid situations. For example, when
the cryptd queue for AESNI is full (easy to trigger with an
artificially low cryptd.cryptd_max_cpu_qlen), requests will be enqueued
to the backlog but still processed. In that case, the async callback
will also be called twice: first with err == -EINPROGRESS, which it
seems we can just ignore, then with err == 0.
Compared to Sabrina's original patch this version uses the new
tls_*crypt_async_wait() helpers and converts the EBUSY to
EINPROGRESS to avoid having to modify all the error handling
paths. The handling is identical.
Fixes: a54667f6728c ("tls: Add support for encryption using async offload accelerator")
Fixes: 94524d8fc965 ("net/tls: Add support for async decryption of tls records")
Co-developed-by: Sabrina Dubroca <sd@xxxxxxxxxxxxxxx>
Signed-off-by: Sabrina Dubroca <sd@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/netdev/9681d1febfec295449a62300938ed2ae66983f28.1694018970.git.sd@xxxxxxxxxxxxxxx/
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Reviewed-by: Simon Horman <horms@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
[v5.15: fixed contextual merge-conflicts in tls_decrypt_done and tls_encrypt_done]
Cc: <stable@xxxxxxxxxxxxxxx> # 5.15
Signed-off-by: Shaoying Xu <shaoyi@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/tls/tls_sw.c | 22 ++++++++++++++++++++++
1 file changed, 22 insertions(+)
--- a/net/tls/tls_sw.c
+++ b/net/tls/tls_sw.c
@@ -175,6 +175,17 @@ static void tls_decrypt_done(struct cryp
struct sk_buff *skb;
unsigned int pages;
+ /* If requests get too backlogged crypto API returns -EBUSY and calls
+ * ->complete(-EINPROGRESS) immediately followed by ->complete(0)
+ * to make waiting for backlog to flush with crypto_wait_req() easier.
+ * First wait converts -EBUSY -> -EINPROGRESS, and the second one
+ * -EINPROGRESS -> 0.
+ * We have a single struct crypto_async_request per direction, this
+ * scheme doesn't help us, so just ignore the first ->complete().
+ */
+ if (err == -EINPROGRESS)
+ return;
+
skb = (struct sk_buff *)req->data;
tls_ctx = tls_get_ctx(skb->sk);
ctx = tls_sw_ctx_rx(tls_ctx);
@@ -273,6 +284,10 @@ static int tls_do_decryption(struct sock
}
ret = crypto_aead_decrypt(aead_req);
+ if (ret == -EBUSY) {
+ ret = tls_decrypt_async_wait(ctx);
+ ret = ret ?: -EINPROGRESS;
+ }
if (ret == -EINPROGRESS) {
if (darg->async)
return 0;
@@ -455,6 +470,9 @@ static void tls_encrypt_done(struct cryp
struct tls_rec *rec;
bool ready = false;
+ if (err == -EINPROGRESS) /* see the comment in tls_decrypt_done() */
+ return;
+
rec = container_of(aead_req, struct tls_rec, aead_req);
msg_en = &rec->msg_encrypted;
@@ -551,6 +569,10 @@ static int tls_do_encryption(struct sock
atomic_inc(&ctx->encrypt_pending);
rc = crypto_aead_encrypt(aead_req);
+ if (rc == -EBUSY) {
+ rc = tls_encrypt_async_wait(ctx);
+ rc = rc ?: -EINPROGRESS;
+ }
if (!rc || rc != -EINPROGRESS) {
atomic_dec(&ctx->encrypt_pending);
sge->offset -= prot->prepend_size;
Patches currently in stable-queue which might be from kuba@xxxxxxxxxx are
queue-5.15/tls-rx-simplify-async-wait.patch
queue-5.15/net-tls-handle-backlogging-of-crypto-requests.patch
queue-5.15/net-tls-factor-out-tls_-crypt_async_wait.patch
queue-5.15/tls-fix-race-between-async-notify-and-socket-close.patch
