From patchwork Fri Feb 23 15:52:16 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Thomas_Wei=C3=9Fschuh?= X-Patchwork-Id: 13569301 Received: from todd.t-8ch.de (todd.t-8ch.de [159.69.126.157]) (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 765E683CD3; Fri, 23 Feb 2024 15:52:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=159.69.126.157 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708703548; cv=none; b=MclbmsEylJ/+elSSdEVIs8LeZqRzamsdONGrL3BqtF17JXtYURZ0P5XotmHt9YrAq0q0fV2aUkOYv4CEZqX3pU3GET3LqHFDq9Qx1v0bIsmh4ByRKV1uhkzcKGK4HBuvfvGP1/sVeEoQCDX1HXeuwR5q0AoVgADVMGoei5Pxq9c= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708703548; c=relaxed/simple; bh=AJVRV4R3xLDBDFjd+6gY0ZeJlPma3kEonzIkr6fkN2A=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:To:Cc; b=M7E1kSEFYX7h+5BbeJ8UMZ7FM4E9mABG7vMMCEqowC5iXNVAY8bci+gaAt8rjPWcqvtVK3vQ0AVACec1Gc0yWGyqXECitoXuLov5GN9eP33PoO38RIJ1hnPU8P7Q8y2wec08NiyoG/VU2tx6DCy+rMgcivJKLfwhXgC9sqdR+aM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=weissschuh.net; spf=pass smtp.mailfrom=weissschuh.net; dkim=pass (1024-bit key) header.d=weissschuh.net header.i=@weissschuh.net header.b=fybScMnw; arc=none smtp.client-ip=159.69.126.157 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=weissschuh.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=weissschuh.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=weissschuh.net header.i=@weissschuh.net header.b="fybScMnw" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=weissschuh.net; s=mail; t=1708703543; bh=AJVRV4R3xLDBDFjd+6gY0ZeJlPma3kEonzIkr6fkN2A=; h=From:Date:Subject:To:Cc:From; b=fybScMnw6ztjnhJh6//od/yfT0jaQwnJ+PQPrEguV5qVD9RWyBY79psyKosZq0JXO tdebnnV6k3r7NkArILvrTJ/AENRrjGSxtDSp8jzxOi6S452vJk666G4ScMV2OOF/JG y34OmWML47curHhdHlh4EoVN3sun1gi6jf2hexns= From: =?utf-8?q?Thomas_Wei=C3=9Fschuh?= Date: Fri, 23 Feb 2024 16:52:16 +0100 Subject: [PATCH v2] sysctl: treewide: constify ctl_table_root::permissions Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20240223-sysctl-const-permissions-v2-1-0f988d0a6548@weissschuh.net> X-B4-Tracking: v=1; b=H4sIAC+/2GUC/42NQQ6CMBBFr0Jm7Rg6RAiuvIdhQdrBTqKFdCpKC He3cAKX7/+8/1dQjsIK12KFyLOojCEDnQqwvg8PRnGZgUqqDFGNuqhNT7Rj0IQTx5fo7ii6xg6 upL6pqwayPkUe5HtM37vMXjSNcTmeZrOnf4zOBg1erKtsa4aa2vb24dyp9W9/Dpyg27btB1/ys zbFAAAA To: Luis Chamberlain , Kees Cook , Joel Granados , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, netdev@vger.kernel.org, =?utf-8?q?Thomas_Wei=C3=9Fschuh?= X-Mailer: b4 0.13.0 X-Developer-Signature: v=1; a=ed25519-sha256; t=1708703543; l=4225; i=linux@weissschuh.net; s=20221212; h=from:subject:message-id; bh=AJVRV4R3xLDBDFjd+6gY0ZeJlPma3kEonzIkr6fkN2A=; b=/fsXRVOZ9LM7U+KZGO0nQmlO8w3CxxklZ9vh2LP8Xz/l1wGHkXNysy0c25wf2b8XLO/onp9DA y3GpYbstrrqABs+tZ9Xxl5TjMASUtr/rOwQ19cJCQvnYd9ecEmRyHOX X-Developer-Key: i=linux@weissschuh.net; a=ed25519; pk=KcycQgFPX2wGR5azS7RhpBqedglOZVgRPfdFSPB1LNw= The permissions callback is not supposed to modify the ctl_table. Enforce this expectation via the typesystem. The patch was created with the following coccinelle script: @@ identifier func, head, ctl; @@ int func( struct ctl_table_header *head, - struct ctl_table *ctl) + const struct ctl_table *ctl) { ... } (insert_entry() from fs/proc/proc_sysctl.c is a false-positive) The three changed locations were validated through manually inspection and compilation. In addition a search for '.permissions =' was done over the full tree to look for places that were missed by coccinelle. None were found. This change also is a step to put "struct ctl_table" into .rodata throughout the kernel. Signed-off-by: Thomas Weißschuh --- To: Luis Chamberlain To: Kees Cook To: Joel Granados To: David S. Miller Signed-off-by: Thomas Weißschuh Changes in v2: - flesh out commit messages - Integrate changes to set_ownership and ctl_table_args into a single series - Link to v1: https://lore.kernel.org/r/20231226-sysctl-const-permissions-v1-1-5cd3c91f6299@weissschuh.net --- The patch is meant to be merged via the sysctl tree. There is an upcoming series that will introduce a new implementation of .permission which would need to be adapted [0]. The adaption would be trivial as the 'table' parameter also not modified there. This change was originally part of the sysctl-const series [1]. To slim down that series and reduce the message load on other maintainers to a minimumble, submit this patch on its own. [0] https://lore.kernel.org/lkml/20240222160915.315255-1-aleksandr.mikhalitsyn@canonical.com/ [1] https://lore.kernel.org/lkml/20231204-const-sysctl-v2-2-7a5060b11447@weissschuh.net/ --- include/linux/sysctl.h | 2 +- ipc/ipc_sysctl.c | 2 +- kernel/ucount.c | 2 +- net/sysctl_net.c | 2 +- 4 files changed, 4 insertions(+), 4 deletions(-) --- base-commit: ffd2cb6b718e189e7e2d5d0c19c25611f92e061a change-id: 20231226-sysctl-const-permissions-d7cfd02a7637 Best regards, diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h index ee7d33b89e9e..0a55b5aade16 100644 --- a/include/linux/sysctl.h +++ b/include/linux/sysctl.h @@ -207,7 +207,7 @@ struct ctl_table_root { void (*set_ownership)(struct ctl_table_header *head, struct ctl_table *table, kuid_t *uid, kgid_t *gid); - int (*permissions)(struct ctl_table_header *head, struct ctl_table *table); + int (*permissions)(struct ctl_table_header *head, const struct ctl_table *table); }; #define register_sysctl(path, table) \ diff --git a/ipc/ipc_sysctl.c b/ipc/ipc_sysctl.c index 8c62e443f78b..b087787f608f 100644 --- a/ipc/ipc_sysctl.c +++ b/ipc/ipc_sysctl.c @@ -190,7 +190,7 @@ static int set_is_seen(struct ctl_table_set *set) return ¤t->nsproxy->ipc_ns->ipc_set == set; } -static int ipc_permissions(struct ctl_table_header *head, struct ctl_table *table) +static int ipc_permissions(struct ctl_table_header *head, const struct ctl_table *table) { int mode = table->mode; diff --git a/kernel/ucount.c b/kernel/ucount.c index 4aa6166cb856..90300840256b 100644 --- a/kernel/ucount.c +++ b/kernel/ucount.c @@ -38,7 +38,7 @@ static int set_is_seen(struct ctl_table_set *set) } static int set_permissions(struct ctl_table_header *head, - struct ctl_table *table) + const struct ctl_table *table) { struct user_namespace *user_ns = container_of(head->set, struct user_namespace, set); diff --git a/net/sysctl_net.c b/net/sysctl_net.c index 051ed5f6fc93..ba9a49de9600 100644 --- a/net/sysctl_net.c +++ b/net/sysctl_net.c @@ -40,7 +40,7 @@ static int is_seen(struct ctl_table_set *set) /* Return standard mode bits for table entry. */ static int net_ctl_permissions(struct ctl_table_header *head, - struct ctl_table *table) + const struct ctl_table *table) { struct net *net = container_of(head->set, struct net, sysctls);