[PATCH] PM: domains: fix integer overflow issues in genpd_parse_state()

From: Nikita Zhandarovich
Date: Tue Apr 18 2023 - 09:08:04 EST


Currently, while calculating residency and latency values, right
operands may overflow if resulting values are big enough.

To prevent this, albeit unlikely case, play it safe and convert
right operands to left ones' type s64.

Found by Linux Verification Center (linuxtesting.org) with static
analysis tool SVACE.

Fixes: 30f604283e05 ("PM / Domains: Allow domain power states to be read from DT")
Signed-off-by: Nikita Zhandarovich <n.zhandarovich@xxxxxxxxxx>
---
drivers/base/power/domain.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index 32084e38b73d..51b9d4eaab5e 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -2939,10 +2939,10 @@ static int genpd_parse_state(struct genpd_power_state *genpd_state,

err = of_property_read_u32(state_node, "min-residency-us", &residency);
if (!err)
- genpd_state->residency_ns = 1000 * residency;
+ genpd_state->residency_ns = 1000LL * residency;

- genpd_state->power_on_latency_ns = 1000 * exit_latency;
- genpd_state->power_off_latency_ns = 1000 * entry_latency;
+ genpd_state->power_on_latency_ns = 1000LL * exit_latency;
+ genpd_state->power_off_latency_ns = 1000LL * entry_latency;
genpd_state->fwnode = &state_node->fwnode;

return 0;
--
2.25.1