From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 95D4147F76B; Tue, 1 Sep 2026 12:16:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788265020; cv=none; b=dDk72a6Y7uFDUU9n3MmfOM1OGsPViE9A9zP8APXpeHavnzGUip1XYmE0BVw+eI94aUTZJ28ugyh97aPs6vSjQV+tyMfa0PDOkWFX6/FRs3U7Bp+UIQ+ZApJwJOKYeYgWlzWK3ovpbU9ptoukRT7sFX9WTKA5R8ZRM+XUaq2ImzY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788265020; c=relaxed/simple; bh=F/j2NqH+w7TNV8U4wBjPBjnprw3X0ltqzP2LkSeZfIQ=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=fZdW2N26sQEJ1X8CHqNe72h6FubetyyWmjqf2nOwpOMo1kOYiJzGabMz9KdyFT+v8eZwSuv3D4UJeRF0pp/35KOhNY2E5wQwEgo/cWM8+PDT1VkbKMsdR/vlG3qPPk0TDcmwDAMhIJ/W9MrLUWVHg9dNj4GMLpLbRqxrWCdAXKs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=O+9iSSna; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="O+9iSSna" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DC7B91F00A3E; Tue, 1 Sep 2026 12:16:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788265019; bh=BcC4YMfM11/fGljBqSTApr2iuzA2VgR75nVP6J1Ns+U=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=O+9iSSnaLb98YWV2BOQGyoaOGowmVxpgGMBak8Z6FXI8QAR7yfBQ5hTcd+G6LrlP/ 2N3uSTb1RL6fK7rW1NtU3wJK5l6FTSj9oBbVOwMx7aXnUUQPjLMMe08l/XbxFMd1VD f3rwyXmzRQJ3l7F3WqTv5BlGcht151R7uj3RafMzmCarjjYPXasUe7GjmJhAkOfT0m MEv390o/4NJj05ivjF2QtHeqWE3XtLSIjeg3bWH8iqN9jr1gVQwnDGIt+K0MnnLYeZ Iz2uszihWkWFAaYqCp7I9mCCcvSp1xY4YZXkgTwQ6g35QIUgSG5GW9CSDbzMeWn5Fw ybQULS0u+cKZA== From: Christian Brauner Date: Tue, 01 Sep 2026 14:14:52 +0200 Subject: [PATCH 27/27] fs: make nop_mnt_idmap and invalid_mnt_idmap const Precedence: bulk X-Mailing-List: linux-integrity@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260901-work-idmap-const-v1-27-54ccd48e100b@kernel.org> References: <20260901-work-idmap-const-v1-0-54ccd48e100b@kernel.org> In-Reply-To: <20260901-work-idmap-const-v1-0-54ccd48e100b@kernel.org> To: linux-fsdevel@vger.kernel.org Cc: Alexander Viro , Jan Kara , Christoph Hellwig , Seth Forshee , Paul Moore , linux-security-module@vger.kernel.org, Mimi Zohar , linux-integrity@vger.kernel.org, Ilya Dryomov , ceph-devel@vger.kernel.org, Carlos Maiolino , linux-xfs@vger.kernel.org, Miklos Szeredi , Amir Goldstein , linux-unionfs@vger.kernel.org, Namjae Jeon , linux-cifs@vger.kernel.org, linux-kernel@vger.kernel.org, "Christian Brauner (Amutable)" X-Mailer: b4 0.17-dev-db0b7 X-Developer-Signature: v=1; a=openpgp-sha256; l=1731; i=brauner@kernel.org; h=from:subject:message-id; bh=F/j2NqH+w7TNV8U4wBjPBjnprw3X0ltqzP2LkSeZfIQ=; b=owGbwMvMwCU28Zj0gdSKO4sYT6slMWRNO7juuASHSvjdD2vZN/1wK1Q8PP2K8SIPF4Nds+KrQ tZn6yupdZSyMIhxMciKKbI4tJuEyy3nqdhslKkBM4eVCWQIAxenAEzkwDGGP1yn3TyV2B+5WR/7 OGsWf21se1dQxD6NlxOZboaqhcUFA1Xwv3b+1lLjefzIN8fv0XP3d2wuslt8guU/o9nzRLPE4j2 MAA== X-Developer-Key: i=brauner@kernel.org; a=openpgp; fpr=4880B8C9BD0E5106FC070F4F7B3C391EFEA93624 Make both static maps const so they end up in rodata. Any attempt to modify them now faults instead of silently corrupting the initial idmapping. Signed-off-by: Christian Brauner (Amutable) --- fs/mnt_idmapping.c | 4 ++-- include/linux/mnt_idmapping.h | 4 ++-- 2 files changed, 4 insertions(+), 4 deletions(-) diff --git a/fs/mnt_idmapping.c b/fs/mnt_idmapping.c index 26704eeb7318..bed57094cef0 100644 --- a/fs/mnt_idmapping.c +++ b/fs/mnt_idmapping.c @@ -28,7 +28,7 @@ struct mnt_idmap { * mapping. This means that {g,u}id 0 is mapped to {g,u}id 0, {g,u}id 1 is * mapped to {g,u}id 1, [...], {g,u}id 1000 to {g,u}id 1000, [...]. */ -struct mnt_idmap nop_mnt_idmap = { +const struct mnt_idmap nop_mnt_idmap = { .count = REFCOUNT_INIT(1), }; EXPORT_SYMBOL_GPL(nop_mnt_idmap); @@ -37,7 +37,7 @@ EXPORT_SYMBOL_GPL(nop_mnt_idmap); * Carries the invalid idmapping of a full 0-4294967295 {g,u}id range. * This means that all {g,u}ids are mapped to INVALID_VFS{G,U}ID. */ -struct mnt_idmap invalid_mnt_idmap = { +const struct mnt_idmap invalid_mnt_idmap = { .count = REFCOUNT_INIT(1), }; EXPORT_SYMBOL_GPL(invalid_mnt_idmap); diff --git a/include/linux/mnt_idmapping.h b/include/linux/mnt_idmapping.h index b445c7660040..78eeef4c2996 100644 --- a/include/linux/mnt_idmapping.h +++ b/include/linux/mnt_idmapping.h @@ -8,8 +8,8 @@ struct mnt_idmap; struct user_namespace; -extern struct mnt_idmap nop_mnt_idmap; -extern struct mnt_idmap invalid_mnt_idmap; +extern const struct mnt_idmap nop_mnt_idmap; +extern const struct mnt_idmap invalid_mnt_idmap; extern struct user_namespace init_user_ns; typedef struct { -- 2.53.0