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 0017C18C332; Wed, 30 Sep 2026 16:58:53 +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=1790787535; cv=none; b=RnrhsHqsd70BLxwN1KtA97fdjjprp01ViPdGK66CLnMK3Dk6R7dbfiGJiIn+MJ3nVXDRB5xQrA3rJbVm8ntX2k7RUKZecgJgIGcqvGjF6kNLV20+nLpb+YmJKAiCJtVnYk7xr4K1QHJ5S1E73QiT6bvY17+bu30thcneLkKqAvY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790787535; c=relaxed/simple; bh=XUzL/3uvUuBKFudojgPv5TqAqn2993I3unYqyP0h9xk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Ohf7G6lcm+c+bWg0Hh4oR6bVAvjJX4/8fyS3uYFV0LiLKLyvhn0xRiRzSEuBFUbQ5KceeJfltCs+1plAffjVi8UJWKuH3yck5SdG7nPKOeII5/GVP46Ok1dloLW5zPdYFhVWlmjUwYoPillUIrPK0k/b524H9tkZoqlQJAopmLE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=hb9xBqrp; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="hb9xBqrp" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5B0791F000FF; Wed, 30 Sep 2026 16:58:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1790787533; bh=a8HkJmQAJrPGZe6/zk7YfZD4WHVBoobKzs/jOvQ2IVk=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=hb9xBqrpanBJZgdaTjUQ0sXq+YMpyxU8Jp+pZbJRnRNDF9sMO15SE+XWi2p+l9tuk 4lTVkFQM/NnSKLD1NE6QnV2MGZ6jzWRnERKkwTcdlSLlwNmhih4qI74RULlun8dIA2 h7hnM8TLvtoBbWDuP595Kfx6NY6GXIa0vJfm2aNg= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Fan Wu Subject: [PATCH 7.2 265/457] ipe: protect the dm-verity root hash with RCU Date: Wed, 30 Sep 2026 17:26:10 +0200 Message-ID: <20260930152351.763985810@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260930152346.024115587@linuxfoundation.org> References: <20260930152346.024115587@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 7.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Fan Wu commit 2776e9c28513a1c855a94792b292cbcc533418c8 upstream. ipe_bdev_setintegrity() frees the old root hash when dm-verity publishes a new one on ->preresume, while policy evaluation can still be dereferencing it. Protect the root hash with RCU. The evaluation path already runs under rcu_read_lock(). Fixes: e155858dd995 ("ipe: add support for dm-verity as a trust provider") Cc: stable@vger.kernel.org Assisted-by: LLM [FW: remove model name according to latest guideline] Signed-off-by: Fan Wu Signed-off-by: Greg Kroah-Hartman --- security/ipe/eval.c | 12 ++++++++---- security/ipe/eval.h | 2 +- security/ipe/hooks.c | 22 +++++++++++++++++----- 3 files changed, 26 insertions(+), 10 deletions(-) --- a/security/ipe/eval.c +++ b/security/ipe/eval.c @@ -134,10 +134,14 @@ static bool evaluate_boot_verified(const static bool evaluate_dmv_roothash(const struct ipe_eval_ctx *const ctx, struct ipe_prop *p) { - return !!ctx->ipe_bdev && - !!ctx->ipe_bdev->root_hash && - ipe_digest_eval(p->value, - ctx->ipe_bdev->root_hash); + const struct digest_info *root_hash; + + if (!ctx->ipe_bdev) + return false; + + root_hash = rcu_dereference(ctx->ipe_bdev->root_hash); + + return root_hash && ipe_digest_eval(p->value, root_hash); } #else static bool evaluate_dmv_roothash(const struct ipe_eval_ctx *const ctx, --- a/security/ipe/eval.h +++ b/security/ipe/eval.h @@ -27,7 +27,7 @@ struct ipe_bdev { #ifdef CONFIG_IPE_PROP_DM_VERITY_SIGNATURE bool dm_verity_signed; #endif /* CONFIG_IPE_PROP_DM_VERITY_SIGNATURE */ - struct digest_info *root_hash; + struct digest_info __rcu *root_hash; }; #endif /* CONFIG_IPE_PROP_DM_VERITY */ --- a/security/ipe/hooks.c +++ b/security/ipe/hooks.c @@ -9,6 +9,7 @@ #include #include #include +#include #include "ipe.h" #include "hooks.h" @@ -232,7 +233,20 @@ void ipe_bdev_free_security(struct block { struct ipe_bdev *blob = ipe_bdev(bdev); - ipe_digest_free(blob->root_hash); + ipe_digest_free(rcu_access_pointer(blob->root_hash)); +} + +static void ipe_set_dmverity_roothash(struct ipe_bdev *blob, + struct digest_info *info) +{ + struct digest_info *old; + + /* Protected by device-mapper's md->suspend_lock */ + old = rcu_replace_pointer(blob->root_hash, info, true); + if (old) { + synchronize_rcu(); + ipe_digest_free(old); + } } #ifdef CONFIG_IPE_PROP_DM_VERITY_SIGNATURE @@ -280,8 +294,7 @@ int ipe_bdev_setintegrity(struct block_d return -EINVAL; if (!value) { - ipe_digest_free(blob->root_hash); - blob->root_hash = NULL; + ipe_set_dmverity_roothash(blob, NULL); return 0; } @@ -301,8 +314,7 @@ int ipe_bdev_setintegrity(struct block_d info->digest_len = digest->digest_len; - ipe_digest_free(blob->root_hash); - blob->root_hash = info; + ipe_set_dmverity_roothash(blob, info); return 0; err: