[PATCH 6.18 05/55] crypto: krb5enc - fix sleepable flag handling in encrypt dispatch

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

6.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Wesley Atwell <atwellwea@gmail.com>

commit 2ef3bac16fb5e9eee4fb1d722578a79b751ea58a upstream.

krb5enc_encrypt_ahash_done() continues encryption from an ahash
completion callback by calling krb5enc_dispatch_encrypt().

That helper takes a flags argument for this continuation path, but it
ignored that argument and reused aead_request_flags(req) when setting
up the skcipher subrequest callback. This can incorrectly preserve
CRYPTO_TFM_REQ_MAY_SLEEP when the encrypt step is started from callback
context.

Preserve the original request flags but clear
CRYPTO_TFM_REQ_MAY_SLEEP for the callback continuation path, and use
the caller-supplied flags when setting up the skcipher subrequest.

Fixes: d1775a177f7f ("crypto: Add 'krb5enc' hash and cipher AEAD algorithm")
Assisted-by: Codex:GPT-5
Signed-off-by: Wesley Atwell <atwellwea@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 crypto/krb5enc.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

--- a/crypto/krb5enc.c
+++ b/crypto/krb5enc.c
@@ -154,7 +154,7 @@ static int krb5enc_dispatch_encrypt(stru
 		dst = scatterwalk_ffwd(areq_ctx->dst, req->dst, req->assoclen);
 
 	skcipher_request_set_tfm(skreq, enc);
-	skcipher_request_set_callback(skreq, aead_request_flags(req),
+	skcipher_request_set_callback(skreq, flags,
 				      krb5enc_encrypt_done, req);
 	skcipher_request_set_crypt(skreq, src, dst, req->cryptlen, req->iv);
 
@@ -192,7 +192,8 @@ static void krb5enc_encrypt_ahash_done(v
 
 	krb5enc_insert_checksum(req, ahreq->result);
 
-	err = krb5enc_dispatch_encrypt(req, 0);
+	err = krb5enc_dispatch_encrypt(req,
+				       aead_request_flags(req) & ~CRYPTO_TFM_REQ_MAY_SLEEP);
 	if (err != -EINPROGRESS)
 		aead_request_complete(req, err);
 }