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 36D421DE4CD; Tue, 8 Oct 2024 13:12:23 +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=1728393143; cv=none; b=nGcXOFo6iOMtPEZgW5GcdiPeTmPQEzSsQjLPY4200EVDUu+5eaEX1c0OO7utkluJ7kgP9Fy3mgBqUbxiWnTr0C1NR0y5XaZwOklwdh93xHBc3uzwRKIZUyN2kLb1VKyAAdO4nrXRekgldI0CB0Y4bW6g6pIm/Bn2nYpEYeblK/8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728393143; c=relaxed/simple; bh=+AFRrX3bQvAN4gI1xTGdzIDtzLaapO4+lhCKgnY77po=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Aj0GGb4M6Pqdv3XUDlvEq7u6rvpv1NorALN7dCA/evivI4XhmIHSrSrmHQrbr/w6rrVnQGx9UM8EspsZQ6gWNStwx5DliLdG6RbkFUe/ULEkfiRzn+BaaIL0Ewi6wA8zQ1569RFEYJq3QJiEDA1y/v4jJ+hDVh8vH0CqNnu6GU8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=E78srPp8; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="E78srPp8" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 99F21C4CEC7; Tue, 8 Oct 2024 13:12:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1728393143; bh=+AFRrX3bQvAN4gI1xTGdzIDtzLaapO4+lhCKgnY77po=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=E78srPp8eETTrNxC8PCAyu3r3+zmu6fV2EburpkrUR6nlh/khr0+q3eJRGqqn4cC1 vj+bCkSn5OfMNfevoFjdfitqPJjVjKLeH4/CWhEHgVQ2yqb+x79Mpe/iIulRt3Jy2W BU17jIpiPG57YHl3JA356w9OSkh+d9xoxcfOSJtI= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jeongjun Park , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.6 066/386] net/xen-netback: prevent UAF in xenvif_flush_hash() Date: Tue, 8 Oct 2024 14:05:11 +0200 Message-ID: <20241008115632.065035087@linuxfoundation.org> X-Mailer: git-send-email 2.46.2 In-Reply-To: <20241008115629.309157387@linuxfoundation.org> References: <20241008115629.309157387@linuxfoundation.org> User-Agent: quilt/0.67 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 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jeongjun Park [ Upstream commit 0fa5e94a1811d68fbffa0725efe6d4ca62c03d12 ] During the list_for_each_entry_rcu iteration call of xenvif_flush_hash, kfree_rcu does not exist inside the rcu read critical section, so if kfree_rcu is called when the rcu grace period ends during the iteration, UAF occurs when accessing head->next after the entry becomes free. Therefore, to solve this, you need to change it to list_for_each_entry_safe. Signed-off-by: Jeongjun Park Link: https://patch.msgid.link/20240822181109.2577354-1-aha310510@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- drivers/net/xen-netback/hash.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/drivers/net/xen-netback/hash.c b/drivers/net/xen-netback/hash.c index ff96f22648efd..45ddce35f6d2c 100644 --- a/drivers/net/xen-netback/hash.c +++ b/drivers/net/xen-netback/hash.c @@ -95,7 +95,7 @@ static u32 xenvif_new_hash(struct xenvif *vif, const u8 *data, static void xenvif_flush_hash(struct xenvif *vif) { - struct xenvif_hash_cache_entry *entry; + struct xenvif_hash_cache_entry *entry, *n; unsigned long flags; if (xenvif_hash_cache_size == 0) @@ -103,8 +103,7 @@ static void xenvif_flush_hash(struct xenvif *vif) spin_lock_irqsave(&vif->hash.cache.lock, flags); - list_for_each_entry_rcu(entry, &vif->hash.cache.list, link, - lockdep_is_held(&vif->hash.cache.lock)) { + list_for_each_entry_safe(entry, n, &vif->hash.cache.list, link) { list_del_rcu(&entry->link); vif->hash.cache.count--; kfree_rcu(entry, rcu); -- 2.43.0