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[157.230.128.187]) by smtp.gmail.com with ESMTPSA id x12sm45523818pfi.122.2020.03.12.17.58.31 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 12 Mar 2020 17:58:31 -0700 (PDT) Received: by 42.do-not-panic.com (Postfix, from userid 1000) id 2B1244028E; Fri, 13 Mar 2020 00:58:31 +0000 (UTC) Date: Fri, 13 Mar 2020 00:58:31 +0000 From: Luis Chamberlain To: Eric Biggers Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, Alexei Starovoitov , Andrew Morton , Greg Kroah-Hartman , Jeff Vander Stoep , Jessica Yu , Kees Cook , NeilBrown , stable@vger.kernel.org Subject: Re: [PATCH v2 2/4] fs/filesystems.c: downgrade user-reachable WARN_ONCE() to pr_warn_once() Message-ID: <20200313005831.GR11244@42.do-not-panic.com> References: <20200312202552.241885-1-ebiggers@kernel.org> <20200312202552.241885-3-ebiggers@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200312202552.241885-3-ebiggers@kernel.org> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Mar 12, 2020 at 01:25:50PM -0700, Eric Biggers wrote: > From: Eric Biggers > > After request_module(), nothing is stopping the module from being > unloaded until someone takes a reference to it via try_get_module(). > > The WARN_ONCE() in get_fs_type() is thus user-reachable, via userspace > running 'rmmod' concurrently. > > Since WARN_ONCE() is for kernel bugs only, not for user-reachable > situations, downgrade this warning to pr_warn_once(). > > Cc: stable@vger.kernel.org > Cc: Alexei Starovoitov > Cc: Andrew Morton > Cc: Greg Kroah-Hartman > Cc: Jeff Vander Stoep > Cc: Jessica Yu > Cc: Kees Cook > Cc: Luis Chamberlain > Cc: NeilBrown > Signed-off-by: Eric Biggers Acked-by: Luis Chamberlain Luis