[PATCH] powerpc/pseries: fix device_node leak in drc-info lookup error paths

[Haotian Zhang <vulab@iscas.ac.cn>]

cpu_to_drc_index() and drc_index_to_cpu() acquire the /cpus device_node
with of_find_node_by_path() and then walk the ibm,drc-info property. When
an entry whose drc_type is not "CPU" is encountered, the code jumps to the
err label, which is *after* the err_of_node_put label, so of_node_put() is
skipped and the reference taken on the /cpus node is leaked on every such
exit.

Jump to err_of_node_put instead so the device_node reference is always
released.

Fixes: e83636ac3334 ("pseries/drc-info: Search DRC properties for CPU indexes")
Assisted-by: DeepSeek-V4.1-Flash
Signed-off-by: Haotian Zhang <vulab@iscas.ac.cn>
---
 arch/powerpc/platforms/pseries/pseries_energy.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/platforms/pseries/pseries_energy.c b/arch/powerpc/platforms/pseries/pseries_energy.c
index fdaf85ecd39b..b3a1c34b3323 100644
--- a/arch/powerpc/platforms/pseries/pseries_energy.c
+++ b/arch/powerpc/platforms/pseries/pseries_energy.c
@@ -66,7 +66,7 @@ static u32 cpu_to_drc_index(int cpu)
 
 			of_read_drc_info_cell(&info, &value, &drc);
 			if (strncmp(drc.drc_type, "CPU", 3))
-				goto err;
+				goto err_of_node_put;
 
 			if (thread_index < drc.last_drc_index)
 				break;
@@ -135,7 +135,7 @@ static int drc_index_to_cpu(u32 drc_index)
 
 			of_read_drc_info_cell(&info, &value, &drc);
 			if (strncmp(drc.drc_type, "CPU", 3))
-				goto err;
+				goto err_of_node_put;
 
 			if (drc_index > drc.last_drc_index) {
 				cpu += drc.num_sequential_elems;
-- 
2.25.1