On Tue, Sep 23, 2025 at 03:15:14PM +0530, Kaushlendra Kumar wrote:
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().
Fixes: b8fe128dad8f ("arch_topology: Adjust initial CPU capacities with current freq") Cc: stable@vger.kernel.org
I wonder if you missed my response on v1[1] before you sent v2/v3 so quickly. The reviewed by tag still stands, just for sake of tools:
Reviewed-by: Sudeep Holla sudeep.holla@arm.com