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=1793210458; b=0xA6JkKFCctD9zXaUU8CMolKctEsLp1amwz+cxQk1Qf+Wu1tUsAxBZCQADd3SX7TmHn9 aaUrNjYJT20wnHCQym5APJyZFvpJjfOPj1h8thL+ybGRbm0TbMJwwqxHgIoNV8vxppChh IipRpj6xRYWs8AmFjgVYkxwNEOCIjuzHyHdYBQybKbuo2ZmRzL+uFpubS9oYHh0Qbygx5 fdEy66akoSDfecFJgIaIyTVOFtpM32QtN8FJrmNR/TsCpwIN4v6mSyd/xWhdVKMannLrh oiQ3gEXGa4efHdYDeUdsjeOKbVHniQFp5YMAVmTaUY6RN0sT9Bur+9N9sU0DsXBc0JQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793210458; 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=s2Jmo/iKvo6gT3tbGZabmLxzTFHFUs7mMQOXw2iRuss=; b=kxssP4Mb8VafqITioAmBECWgWlkhaDBv7GMHt85ghlq1Vszm8I5kg5+30tPwowoWH4LO Rr87R3ctpzUuaauPGS5n5l9XkGRRUhj5cWPuaIrdqkkK0Y+8egDBZCahShhKrcwdLO5Vk CcN8o+frm69qJY8vJnpg37mU22nTUk0qOg3NFVycgY174YeMW5put2j69TBjQkKqqmqce A291s8lfqcCZXTLm055jBw5FU6va5JN4KLHVBWjU247h0CpoOxkreXYgybOeGAFjZ72r+ P9D8lzG/t+xXuC7Eq+U3cUeo8Ez9jzQCl09qf6M6Vi0p+Okobf2h525Dy/Ong6QSe9A== 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=POFLJiPg; 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 ED511606A32C; Wed, 28 Oct 2026 18:00:57 +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=POFLJiPg Received: by smtp.kernel.org (Postfix) with ESMTPSA id 492CD1F01825; Wed, 28 Oct 2026 18:00:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793210457; bh=s2Jmo/iKvo6gT3tbGZabmLxzTFHFUs7mMQOXw2iRuss=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=POFLJiPgo8sZeS32+kGlfd1CUCRxJrGDrcnL0dZlRm08capzZu5KLSg9rWnLaMYRz zKDqm5Hk6BkgwFXz/EDNzIk4hH2kTwX/pIEzb2+EwnvjXR1PD6EvrWRERumsLE38Ub ANzC8pjze1FigHNDz3Iawh+u85s4VvEkVE7922e0= 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 5.15 004/571] device property: fix infinite loop in fwnode_for_each_child_node() Date: Wed, 28 Oct 2026 17:52:31 +0100 Message-ID: <20261028170008.121698248@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261028170008.009143722@linuxfoundation.org> References: <20261028170008.009143722@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 5.15-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 e490166261d9a..262e43a9e8bad 100644 --- a/drivers/base/property.c +++ b/drivers/base/property.c @@ -748,18 +748,31 @@ 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