From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id C49B5C4725D for ; Mon, 22 Jan 2024 12:39:27 +0000 (UTC) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=aa05kvtt; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=aa05kvtt; dkim-atps=neutral Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4TJVCf2lDYz3by8 for ; Mon, 22 Jan 2024 23:39:26 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=aa05kvtt; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=aa05kvtt; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=redhat.com (client-ip=170.10.129.124; helo=us-smtp-delivery-124.mimecast.com; envelope-from=dhowells@redhat.com; receiver=lists.ozlabs.org) Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4TJVCL2TM8z3byl for ; Mon, 22 Jan 2024 23:39:10 +1100 (AEDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1705927147; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=8CJ3I/7LDGs8hexTud6zRTfvlS0atGDHH81M3ADEHcQ=; b=aa05kvtt3HsTXHgovh9UtJ8kY/gRoDeW3PRBhkPLmL/HDWEN3FasUoBg78tnCGeJxNb5LY MU8fyureIawjyzoVd7nLqdTkSOixUvViX4RUS8rMRnGEld03yMoKrKzZfdtdi64KQNYCZM hpeT65/vk8E0huiGp3slLgBlt6GvxKo= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1705927147; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=8CJ3I/7LDGs8hexTud6zRTfvlS0atGDHH81M3ADEHcQ=; b=aa05kvtt3HsTXHgovh9UtJ8kY/gRoDeW3PRBhkPLmL/HDWEN3FasUoBg78tnCGeJxNb5LY MU8fyureIawjyzoVd7nLqdTkSOixUvViX4RUS8rMRnGEld03yMoKrKzZfdtdi64KQNYCZM hpeT65/vk8E0huiGp3slLgBlt6GvxKo= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-277-IYJ33U9IOce8J_5Yad4F5w-1; Mon, 22 Jan 2024 07:39:03 -0500 X-MC-Unique: IYJ33U9IOce8J_5Yad4F5w-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 6003885A58B; Mon, 22 Jan 2024 12:39:02 +0000 (UTC) Received: from warthog.procyon.org.com (unknown [10.42.28.67]) by smtp.corp.redhat.com (Postfix) with ESMTP id 7DE802026D66; Mon, 22 Jan 2024 12:39:00 +0000 (UTC) From: David Howells To: Christian Brauner Subject: [PATCH 04/10] netfs, fscache: Prevent Oops in fscache_put_cache() Date: Mon, 22 Jan 2024 12:38:37 +0000 Message-ID: <20240122123845.3822570-5-dhowells@redhat.com> In-Reply-To: <20240122123845.3822570-1-dhowells@redhat.com> References: <20240122123845.3822570-1-dhowells@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.4 X-BeenThere: linux-erofs@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Development of Linux EROFS file system List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-cifs@vger.kernel.org, linux-nfs@vger.kernel.org, v9fs@lists.linux.dev, Jeff Layton , linux-kernel@vger.kernel.org, Matthew Wilcox , David Howells , linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, netfs@lists.linux.dev, ceph-devel@vger.kernel.org, linux-erofs@lists.ozlabs.org, linux-afs@lists.infradead.org, Dan Carpenter Errors-To: linux-erofs-bounces+linux-erofs=archiver.kernel.org@lists.ozlabs.org Sender: "Linux-erofs" From: Dan Carpenter This function dereferences "cache" and then checks if it's IS_ERR_OR_NULL(). Check first, then dereference. Fixes: 9549332df4ed ("fscache: Implement cache registration") Signed-off-by: Dan Carpenter Signed-off-by: David Howells Link: https://lore.kernel.org/r/e84bc740-3502-4f16-982a-a40d5676615c@moroto.mountain/ # v2 --- fs/netfs/fscache_cache.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/netfs/fscache_cache.c b/fs/netfs/fscache_cache.c index d645f8b302a2..9397ed39b0b4 100644 --- a/fs/netfs/fscache_cache.c +++ b/fs/netfs/fscache_cache.c @@ -179,13 +179,14 @@ EXPORT_SYMBOL(fscache_acquire_cache); void fscache_put_cache(struct fscache_cache *cache, enum fscache_cache_trace where) { - unsigned int debug_id = cache->debug_id; + unsigned int debug_id; bool zero; int ref; if (IS_ERR_OR_NULL(cache)) return; + debug_id = cache->debug_id; zero = __refcount_dec_and_test(&cache->ref, &ref); trace_fscache_cache(debug_id, ref - 1, where);