From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 10412FC08 for ; Mon, 15 May 2023 17:36:13 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6861AC433D2; Mon, 15 May 2023 17:36:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1684172172; bh=gUsLYDrdJw3o6YNcAkfmqQJTy4eBF7YssFNUN/JNt1s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nnbS/kF7ZAuW2g7FiOvN1zB1mf7UOsf+Y7VJeXsoirsffLtsYQNITnYbgElkYDviT 225YvL0wG4vi7rwjPuC/kk2HoHulaCJ1CJuHQMHdAsPtS2UaoTtcgzBkoCS+xkCtTq P3gRVnZiMdAYkmZLlFNyNdkW8S/0Y1rrSd2KTUIs= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, =?UTF-8?q?Toke=20H=C3=B8iland-J=C3=B8rgensen?= , Herbert Xu Subject: [PATCH 5.10 038/381] crypto: api - Demote BUG_ON() in crypto_unregister_alg() to a WARN_ON() Date: Mon, 15 May 2023 18:24:49 +0200 Message-Id: <20230515161738.536273522@linuxfoundation.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230515161736.775969473@linuxfoundation.org> References: <20230515161736.775969473@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Toke Høiland-Jørgensen commit a543ada7db729514ddd3ba4efa45f4c7b802ad85 upstream. The crypto_unregister_alg() function expects callers to ensure that any algorithm that is unregistered has a refcnt of exactly 1, and issues a BUG_ON() if this is not the case. However, there are in fact drivers that will call crypto_unregister_alg() without ensuring that the refcnt has been lowered first, most notably on system shutdown. This causes the BUG_ON() to trigger, which prevents a clean shutdown and hangs the system. To avoid such hangs on shutdown, demote the BUG_ON() in crypto_unregister_alg() to a WARN_ON() with early return. Cc stable because this problem was observed on a 6.2 kernel, cf the link below. Link: https://lore.kernel.org/r/87r0tyq8ph.fsf@toke.dk Cc: stable@vger.kernel.org Signed-off-by: Toke Høiland-Jørgensen Signed-off-by: Herbert Xu Signed-off-by: Greg Kroah-Hartman --- crypto/algapi.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/crypto/algapi.c +++ b/crypto/algapi.c @@ -456,7 +456,9 @@ void crypto_unregister_alg(struct crypto if (WARN(ret, "Algorithm %s is not registered", alg->cra_driver_name)) return; - BUG_ON(refcount_read(&alg->cra_refcnt) != 1); + if (WARN_ON(refcount_read(&alg->cra_refcnt) != 1)) + return; + if (alg->cra_destroy) alg->cra_destroy(alg);