FAILED: patch "[PATCH] arch_topology: Fix incorrect error check in" failed to apply to 5.15-stable tree

The patch below does not apply to the 5.15-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x 2eead19334516c8e9927c11b448fbe512b1f18a1
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2025102641-hydrant-wake-e29d@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 2eead19334516c8e9927c11b448fbe512b1f18a1 Mon Sep 17 00:00:00 2001
From: Kaushlendra Kumar <[email protected]>
Date: Tue, 23 Sep 2025 23:13:08 +0530
Subject: [PATCH] arch_topology: Fix incorrect error check in
topology_parse_cpu_capacity()

Fix incorrect use of PTR_ERR_OR_ZERO() in topology_parse_cpu_capacity() which causes the code to proceed with NULL clock pointers. The current logic uses !PTR_ERR_OR_ZERO(cpu_clk) which evaluates to true for both valid pointers and NULL, leading to potential NULL pointer dereference in clk_get_rate().

Per include/linux/err.h documentation, PTR_ERR_OR_ZERO(ptr) returns:
"The error code within @ptr if it is an error pointer; 0 otherwise."

This means PTR_ERR_OR_ZERO() returns 0 for both valid pointers AND NULL pointers. Therefore !PTR_ERR_OR_ZERO(cpu_clk) evaluates to true (proceed) when cpu_clk is either valid or NULL, causing clk_get_rate(NULL) to be called when of_clk_get() returns NULL.

Replace with !IS_ERR_OR_NULL(cpu_clk) which only proceeds for valid pointers, preventing potential NULL pointer dereference in clk_get_rate().

index 1037169abb45..e1eff05bea4a 100644
@@ -292,7 +292,7 @@ bool __init topology_parse_cpu_capacity(struct device_node *cpu_node, int cpu)
 		 * frequency (by keeping the initial capacity_freq_ref value).
 		 */
 		cpu_clk = of_clk_get(cpu_node, 0);
-		if (!PTR_ERR_OR_ZERO(cpu_clk)) {
+		if (!IS_ERR_OR_NULL(cpu_clk)) {
 			per_cpu(capacity_freq_ref, cpu) =
 				clk_get_rate(cpu_clk) / HZ_PER_KHZ;
 			clk_put(cpu_clk);

From: Kaushlendra Kumar <[email protected]>

[ Upstream commit 2eead19334516c8e9927c11b448fbe512b1f18a1 ]

Fix incorrect use of PTR_ERR_OR_ZERO() in topology_parse_cpu_capacity() which causes the code to proceed with NULL clock pointers. The current logic uses !PTR_ERR_OR_ZERO(cpu_clk) which evaluates to true for both valid pointers and NULL, leading to potential NULL pointer dereference in clk_get_rate().

Per include/linux/err.h documentation, PTR_ERR_OR_ZERO(ptr) returns:
"The error code within @ptr if it is an error pointer; 0 otherwise."

This means PTR_ERR_OR_ZERO() returns 0 for both valid pointers AND NULL pointers. Therefore !PTR_ERR_OR_ZERO(cpu_clk) evaluates to true (proceed) when cpu_clk is either valid or NULL, causing clk_get_rate(NULL) to be called when of_clk_get() returns NULL.

Replace with !IS_ERR_OR_NULL(cpu_clk) which only proceeds for valid pointers, preventing potential NULL pointer dereference in clk_get_rate().

---
 drivers/base/arch_topology.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

index 31bd6f4e5dc47..69dea9825f6a5 100644
@@ -290,7 +290,7 @@ bool __init topology_parse_cpu_capacity(struct device_node *cpu_node, int cpu)
 		 * frequency (by keeping the initial freq_factor value).
 		 */
 		cpu_clk = of_clk_get(cpu_node, 0);
-		if (!PTR_ERR_OR_ZERO(cpu_clk)) {
+		if (!IS_ERR_OR_NULL(cpu_clk)) {
 			per_cpu(freq_factor, cpu) =
 				clk_get_rate(cpu_clk) / 1000;
 			clk_put(cpu_clk);

2.51.0