From patchwork Mon Feb 3 22:32:04 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Amir Goldstein X-Patchwork-Id: 13958342 Received: from mail-ej1-f54.google.com (mail-ej1-f54.google.com [209.85.218.54]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 155641FFC7F for ; Mon, 3 Feb 2025 22:32:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.218.54 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738621936; cv=none; b=XsnYN42wbYdZuKE734wqjOqgJ+Te5TBG0T32+j2vvc2qETDsUgRU29RaH9v5I+mGRE4iJ9IisKoJKbu6EcT+u/4SjHc/aG3xZzE7/8rjqytXsdq1FrwCZwMvTPb2RYSEOpFGysW0vfzfZsQGenuOoHbzL0u/PYBZoLnB8wKDuiE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738621936; c=relaxed/simple; bh=0/bbVrNVeVVmEpyRvFaB9DE+nYBCaOhos+L41mmADAw=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=Be2VPmsNVIgeQrY4DgvYXOd4MSZCuYozEgIghnaUH7Fet7RoG/bWURNoS1yoK3hTbmMHKJ3JVIJJzXfgsynJXMWHTume94tkxXEKqR4PQOvjrHaBfNzGpk+n1/KBoFWOQhmRXZ1PT5XC5i9tiw6/qdMUf08rkJNN+Ew7uo+C+2c= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=AmkpvnXZ; arc=none smtp.client-ip=209.85.218.54 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="AmkpvnXZ" Received: by mail-ej1-f54.google.com with SMTP id a640c23a62f3a-aa67ac42819so743600966b.0 for ; Mon, 03 Feb 2025 14:32:14 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1738621933; x=1739226733; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=RFxgfqw9HRB+5xQNdBfsHKii2SrLpZfUufppKw/irMo=; b=AmkpvnXZVzgqHOvjb3uSx7X5PZ8fzG64hkclt9Sq2wTTq16x3su/Q1Hmz8hvtLLvXu Dm+92MRpR1oj1F8y8TvOaA1IRovDU/EmAyEmU0QEFZdDP+BfP9LE8kSfNnEcLnrBtvN2 kVQvCwhBSGs+NPuxv4L8rEV8z5YzRaxu96rwA8ommRDWy/soalMj6+/HU6hkvmajDVM9 oYDaopD2kv5cjTC6Ph8uZitHbWbEkfij4J2KdeG7YSmr+zFDqy5w/dizdWccHqOrZnwE h+rTaagRlASmZ/wrzIyGQvGYOBNgArxL4kbweFsoSKk0TqMuY7X4A2NJzO0VcLcTqqnA RHnA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1738621933; x=1739226733; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=RFxgfqw9HRB+5xQNdBfsHKii2SrLpZfUufppKw/irMo=; b=VrER40wzzjfqtySS+MWjyYAE18XBk4B/Dlb68SNsQ8Y17jPmDq4Fn+OaTQBi6ursn7 /+WpEN9AEvqMxvyHn/qBcFM3IcAF4uvMw8ASNtUTywwVJrhHGBJTHUKw5BAtQ86+LuPP 1AbwRyKtjqh8fjLDSi/mNF9byFCWLaNxgmU3bqMqarcsNpwxIzcQYB7oifUeh34uR2Ax 5aqelBRHJekaxLvs/DZI2OATRmWiknCJ3VTUVp9IikiIgIuFCMoGfY6OBf1uB2s/NP4Y 1dPPMlDP/r/+ZB8FIaYHYUvIiglSbCDF8GluLDNwKJ772vtTLd0jQEFe6IZXTnRYnGAM o6PQ== X-Forwarded-Encrypted: i=1; AJvYcCWmOAtFXUVBO4p5hxHIC9dNcZxivjaLqyjsbUd84N0RMo28uUxQTxCseIb6h59RjffZJL7AluWfjZ5Z4Vvj@vger.kernel.org X-Gm-Message-State: AOJu0YwU9YRlMSvV5MGWJYcF4VZXijZ4u3l4Z6d1N0Ytcvp8pbiYoVa+ jwkFM5qKnHYke0jHMafPLUS+ZCir3MsjwwuVw7DG8+/MV7TKUbxKaY+sfhoR X-Gm-Gg: ASbGnct9x2jvCemtAC283JtYpaIMbiyp59i53gW/cPG5OjELsEPrC3P2lRMY1pYBSPZ rsTa7axzt1uij8ZI6llzV8uXzAQzKWx0uJYuvjstjwL+bon1YYZjEFGq1txCf2N1wY9tf3jjUEe 77aHeNrAcIy22bogdGl9CoJenFC55gCmiDaJj2rx9GZR4DMZOS7ZuAn3sZG9v8carVO1YzZBrCk dqaz7qwluxjK6UkQfIMVLWqXX7Td2y/ZxAjOScLlAxjUqlV60CAHoP6gTrQBBpfJlnOfi6ll9w9 gTaz1E6Er2wE56lPEPf2JdJQHswIkR9QqaFJPQTGzM+NY5PG0QYc+UR4uxCbLoK55/vPx7YIu57 bhnsUjiNu1Mgj X-Google-Smtp-Source: AGHT+IHzlKwLVWw4IVYzO30LEZ1HqeolMs1QSBzegYLtizg0i5AgUH0VH7IJh900KL/NDVSdErpNbA== X-Received: by 2002:a17:906:a3d3:b0:ab6:d9f7:fd71 with SMTP id a640c23a62f3a-ab6d9f83783mr2234630966b.51.1738621932645; Mon, 03 Feb 2025 14:32:12 -0800 (PST) Received: from amir-ThinkPad-T480.arnhem.chello.nl (92-109-99-123.cable.dynamic.v4.ziggo.nl. [92.109.99.123]) by smtp.gmail.com with ESMTPSA id 4fb4d7f45d1cf-5dc724a9c5fsm8339651a12.54.2025.02.03.14.32.11 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 03 Feb 2025 14:32:12 -0800 (PST) From: Amir Goldstein To: Christian Brauner Cc: Jan Kara , Alex Williamson , Linus Torvalds , linux-fsdevel@vger.kernel.org Subject: [PATCH 2/3] fsnotify: disable notification by default for all pseudo files Date: Mon, 3 Feb 2025 23:32:04 +0100 Message-Id: <20250203223205.861346-3-amir73il@gmail.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20250203223205.861346-1-amir73il@gmail.com> References: <20250203223205.861346-1-amir73il@gmail.com> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Most pseudo files are not applicable for fsnotify events at all, let alone to the new pre-content events. Disable notifications to all files allocated with alloc_file_pseudo() and enable legacy inotify events for the specific cases of pipe and socket, which have known users of inotify events. Pre-content events are also kept disabled for sockets and pipes. Fixes: 20bf82a898b6 ("mm: don't allow huge faults for files with pre content watches") Reported-by: Alex Williamson Closes: https://lore.kernel.org/linux-fsdevel/20250131121703.1e4d00a7.alex.williamson@redhat.com/ Suggested-by: Linus Torvalds Link: https://lore.kernel.org/linux-fsdevel/CAHk-=wi2pThSVY=zhO=ZKxViBj5QCRX-=AS2+rVknQgJnHXDFg@mail.gmail.com/ Tested-by: Alex Williamson Signed-off-by: Amir Goldstein --- fs/file_table.c | 11 +++++++++++ fs/open.c | 4 ++-- fs/pipe.c | 6 ++++++ net/socket.c | 5 +++++ 4 files changed, 24 insertions(+), 2 deletions(-) diff --git a/fs/file_table.c b/fs/file_table.c index f0291a66f9db4..35b93da6c5cb1 100644 --- a/fs/file_table.c +++ b/fs/file_table.c @@ -375,7 +375,13 @@ struct file *alloc_file_pseudo(struct inode *inode, struct vfsmount *mnt, if (IS_ERR(file)) { ihold(inode); path_put(&path); + return file; } + /* + * Disable all fsnotify events for pseudo files by default. + * They may be enabled by caller with file_set_fsnotify_mode(). + */ + file_set_fsnotify_mode(file, FMODE_NONOTIFY); return file; } EXPORT_SYMBOL(alloc_file_pseudo); @@ -400,6 +406,11 @@ struct file *alloc_file_pseudo_noaccount(struct inode *inode, return file; } file_init_path(file, &path, fops); + /* + * Disable all fsnotify events for pseudo files by default. + * They may be enabled by caller with file_set_fsnotify_mode(). + */ + file_set_fsnotify_mode(file, FMODE_NONOTIFY); return file; } EXPORT_SYMBOL_GPL(alloc_file_pseudo_noaccount); diff --git a/fs/open.c b/fs/open.c index 3fcbfff8aede8..1be20de9f283a 100644 --- a/fs/open.c +++ b/fs/open.c @@ -936,8 +936,8 @@ static int do_dentry_open(struct file *f, /* * Set FMODE_NONOTIFY_* bits according to existing permission watches. - * If FMODE_NONOTIFY was already set for an fanotify fd, this doesn't - * change anything. + * If FMODE_NONOTIFY mode was already set for an fanotify fd or for a + * pseudo file, this call will not change the mode. */ file_set_fsnotify_mode_from_watchers(f); error = fsnotify_open_perm(f); diff --git a/fs/pipe.c b/fs/pipe.c index 94b59045ab44b..ce1af7592780d 100644 --- a/fs/pipe.c +++ b/fs/pipe.c @@ -960,6 +960,12 @@ int create_pipe_files(struct file **res, int flags) res[1] = f; stream_open(inode, res[0]); stream_open(inode, res[1]); + /* + * Disable permission and pre-content events, but enable legacy + * inotify events for legacy users. + */ + file_set_fsnotify_mode(res[0], FMODE_NONOTIFY_PERM); + file_set_fsnotify_mode(res[1], FMODE_NONOTIFY_PERM); return 0; } diff --git a/net/socket.c b/net/socket.c index 262a28b59c7f0..28bae5a942341 100644 --- a/net/socket.c +++ b/net/socket.c @@ -479,6 +479,11 @@ struct file *sock_alloc_file(struct socket *sock, int flags, const char *dname) sock->file = file; file->private_data = sock; stream_open(SOCK_INODE(sock), file); + /* + * Disable permission and pre-content events, but enable legacy + * inotify events for legacy users. + */ + file_set_fsnotify_mode(file, FMODE_NONOTIFY_PERM); return file; } EXPORT_SYMBOL(sock_alloc_file);