From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793208130; b=l0nIvUqDHTWF+DRX04FBjPTKaopGQ/I2yu8iFvTgtYU2axXnyBPqNWmX4skRnzFCq2fx PfmZYQOSa1z6EviTMP/o8acv6yzhmrtOCtsAkKbsA8deYT56oDdRqv1k9NKrkj+ak2yB9 OhmxejE/dskTcT8xfmYivG1uohId/2FaiKvxYsHazpyRvWmcd/fp89Hg5ehYEMYEN0Woj CaZYxAnCq4oTryHAQhyZfdbyAyVslhqnyxBUciIMQShM1mt/oPVQ490nL1LUI23um9Fsg 6jM1v+OdRSF4vLc1cgWRLgZiQdcfpVREwFCLgef4snypa6QYe9rBQN92WAbSrGWbRyQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793208130; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Type:Content-Transfer-Encoding; bh=AwKYHpiBBsa2I3YuvDgz5iNUuviSwSrYb7fLM6O8p3k=; b=Rprzm3/2ZNscs1IzyfTxbbEPg8H3J/VqlZUchFioDecgfeij91sqwhgPBVc1fB1qjD8z X1xfB21exfTMROrKNWiOhnjj+TihUowEuHSZjGb4uoTZv3ktf9oRRPB/cf36J+yKVxDDH 7gRPcH3OHfJaOI18/7nLtARKhm2I4SmJSqzlb3OIAd17Ta7GnopTgIfQELJvxiSAOPORB NcGgT80MjaLcPaDmpfa0RDWOL4/g7GSUsEl7PZhCLjSJXhwl8oygfieEAQi2Z5T1IDpky u1cbEerSopa4cOmqUdsXYy73WdB0RwHnwekaqkm9vTyd0RlGmUtESJPuV+b4DDtdKZQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=FgdA8vo+; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DF270606A331; Wed, 28 Oct 2026 17:22:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=FgdA8vo+ Received: by smtp.kernel.org (Postfix) with ESMTPSA id E6F6E1F01825; Wed, 28 Oct 2026 17:22:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793208129; bh=AwKYHpiBBsa2I3YuvDgz5iNUuviSwSrYb7fLM6O8p3k=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=FgdA8vo+pDWjixYhlvd0GQesECo/f1WUH83/dxjnS/EFdIsMwrN8NG2SyW47tYaX4 cRtcUFfPJhLysH6kqsjGuLh9iEtCY+/zmFkvEyGWNqYTAEx0v3Tr20LA6vQixJKaMx AlN29/rDbd0eSrayaeOVRihuUsxQXiKataUmft5g= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Xu Yang , Andy Shevchenko , Sasha Levin Subject: [PATCH 5.10 004/516] device property: fix infinite loop in fwnode_for_each_child_node() Date: Wed, 28 Oct 2026 17:52:36 +0100 Message-ID: <20261028170003.631388847@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261028170003.522232767@linuxfoundation.org> References: <20261028170003.522232767@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: patches@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 5.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Xu Yang [ Upstream commit 1900692555826753adab8799a1a8d50bb1ee200c ] When iterate over children of a fwnode that has a secondary fwnode, fwnode_get_next_child_node() can enter an infinite loop if the secondary fwnode has more than one child. Parent Child (Primary fwnode) FWa: {FWa1, FWa2, FWa3} (Secondary fwnode) FWb: {FWb1, FWb2} In this case: ┌─> fwnode_get_next_child_node(FWa, FWa1) │ - fwnode_call_ptr_op(FWa, get_next_child_node, FWa1) returns FWa2 │ │ ... │ │ fwnode_get_next_child_node(FWa, FWa3) │ - fwnode_call_ptr_op(FWa, get_next_child_node, FWa3) returns NULL │ - fwnode_call_ptr_op(FWb, get_next_child_node, FWa3) returns FWb1 │ │ fwnode_get_next_child_node(FWa, FWb1) │ - fwnode_call_ptr_op(FWa, get_next_child_node, FWb1) returns FWa1 └────┘ This cause fwnode_for_each_child_node() to loop indefinitely, reapeatedly output {FWa1, FWa2, FWa3, FWb1, FWa1, ...}. The root cause is that when the current child (FWb1) belongs to the secondary fwnode, calling get_next_child_node() on the parimary fwnode incorrectly returns the first child (FWa1) again instead of NULL. Fix this by dynamically checking the parent fwnode of the current child before calling get_next_child_node(). This approach follows the pattern established in commit b5b41ab6b0c1 ("device property: Check fwnode->secondary in fwnode_graph_get_next_endpoint()"). Fixes: 2692c614f8f0 ("device property: Allow secondary lookup in fwnode_get_next_child_node()") Cc: stable@vger.kernel.org Signed-off-by: Xu Yang Tested-by: Andy Shevchenko Signed-off-by: Andy Shevchenko Tested-by: Xu Yang Link: https://patch.msgid.link/20260611203537.1786399-2-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/base/property.c | 19 ++++++++++++++++--- 1 file changed, 16 insertions(+), 3 deletions(-) diff --git a/drivers/base/property.c b/drivers/base/property.c index 4b16531d77916..2601c1d806c51 100644 --- a/drivers/base/property.c +++ b/drivers/base/property.c @@ -740,18 +740,31 @@ struct fwnode_handle * fwnode_get_next_child_node(const struct fwnode_handle *fwnode, struct fwnode_handle *child) { + const struct fwnode_handle *parent; + struct fwnode_handle *child_parent __free(fwnode_handle) = NULL; struct fwnode_handle *next; - if (IS_ERR_OR_NULL(fwnode)) + /* + * If this function is in a loop and the previous iteration returned + * an child from fwnode->secondary, then we need to use the secondary + * as parent rather than @fwnode. + */ + if (child) { + child_parent = fwnode_get_parent(child); + parent = child_parent; + } else { + parent = fwnode; + } + if (IS_ERR_OR_NULL(parent)) return NULL; /* Try to find a child in primary fwnode */ - next = fwnode_call_ptr_op(fwnode, get_next_child_node, child); + next = fwnode_call_ptr_op(parent, get_next_child_node, child); if (next) return next; /* When no more children in primary, continue with secondary */ - return fwnode_call_ptr_op(fwnode->secondary, get_next_child_node, child); + return fwnode_get_next_child_node(parent->secondary, NULL); } EXPORT_SYMBOL_GPL(fwnode_get_next_child_node); -- 2.53.0