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 5510C1BC2A; Mon, 5 Feb 2024 12:31:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707136312; cv=none; b=ElKzCaaEUKr7wGaxrx0Z9k8gr8Z4SllBG5EdPstjo+DbugsU7vw79zo9/n4YxM8nNPgCTwLz04xMZy1RnlBeUc/GJ3r3EOgKIfjoeoxMs68/JOgnUclR50hMGIQkjURbPUJZmQBkAIYjEPQUEtdx30+K2xTLssWat50Wo5b7NmI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707136312; c=relaxed/simple; bh=OvthZE2bvXcBV8LXD8wNl6xF83BZcROXQGXGKL5j77E=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=a6OKq58uRklDkoTgmhv1IMtCMxHIm5B4m7ytwuon+z5ISqLr28WBWWVIS5ntzZEdQ21OhxmUy4Yx9kvL6gD5mk26Mv0EsAr/kOslDUwfRI1ZGqqb64nApBxS7p8/DVYNk3iMmMEFF43gjYV2po8cK9GOjuhz7L9NDrz98tZRsoY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=IvkYEcag; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="IvkYEcag" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 20A50C433F1; Mon, 5 Feb 2024 12:31:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1707136311; bh=OvthZE2bvXcBV8LXD8wNl6xF83BZcROXQGXGKL5j77E=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=IvkYEcagw9GLn2Xyj27UFyIrKvramr9XYJda4GwFgpoAzGHJ8zlji5QCefmE85kEA hgyI4tDT2LPrie4Vixfa2Lm76eazhGxJjbDJJK2jZ9kdp4wAJJoXXqOxQXWb7TgsQV PsvK7Pmi5GM/YKqbl8MON2xb23fMatq7kv21lylMlheR6k79eL6IBZBnK1DRl+kBTk JRX5o5rU9qMs4O5JSdaA2mjsTPh0H4TZfqItF20s13sdMWTLFXRCpDX9Fh/s7DTxDj Ol8iRSJvR4sIjUnPyR1YBhyP3a8UMDWetTcTXlLahygxEqdkLSgwNb2wOj8zSsc4Lj IvBAZSymNIHJQ== Date: Mon, 5 Feb 2024 13:31:47 +0100 From: Christian Brauner To: Al Viro Cc: linux-fsdevel@vger.kernel.org, Linus Torvalds , linux-ext4@vger.kernel.org, linux-nfs@vger.kernel.org, Miklos Szeredi , linux-cifs@vger.kernel.org Subject: Re: [PATCH 11/13] fuse: fix UAF in rcu pathwalks Message-ID: <20240205-gesponnen-mahnmal-ad1aef11676a@brauner> References: <20240204021436.GH2087318@ZenIV> <20240204021739.1157830-1-viro@zeniv.linux.org.uk> <20240204021739.1157830-11-viro@zeniv.linux.org.uk> Precedence: bulk X-Mailing-List: linux-ext4@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20240204021739.1157830-11-viro@zeniv.linux.org.uk> On Sun, Feb 04, 2024 at 02:17:37AM +0000, Al Viro wrote: > ->permission(), ->get_link() and ->inode_get_acl() might dereference > ->s_fs_info (and, in case of ->permission(), ->s_fs_info->fc->user_ns > as well) when called from rcu pathwalk. > > Freeing ->s_fs_info->fc is rcu-delayed; we need to make freeing ->s_fs_info > and dropping ->user_ns rcu-delayed too. > > Signed-off-by: Al Viro > --- Reviewed-by: Christian Brauner