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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().

Cc: stable <stable@kernel.org>
Signed-off-by: Kaushlendra Kumar <kaushlendra.kumar@intel.com>
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Fixes: b8fe128dad ("arch_topology: Adjust initial CPU capacities with current freq")
Link: https://patch.msgid.link/20250923174308.1771906-1-kaushlendra.kumar@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Kaushlendra Kumar 2025-09-23 23:13:08 +05:30 committed by Greg Kroah-Hartman
parent cfec502b3d
commit 2eead19334
1 changed files with 1 additions and 1 deletions
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2
drivers/base/arch_topology.c
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@ -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);