6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Sivan Zohar-Kotzer sivany32@gmail.com
[ Upstream commit 46dc57406887dd02565cb264224194a6776d882b ]
The get_pd_power_uw() function can crash with a NULL pointer dereference when em_cpu_get() returns NULL. This occurs when a CPU becomes impossible during runtime, causing get_cpu_device() to return NULL, which propagates through em_cpu_get() and leads to a crash when em_span_cpus() dereferences the NULL pointer.
Add a NULL check after em_cpu_get() and return 0 if unavailable, matching the existing fallback behavior in __dtpm_cpu_setup().
Fixes: eb82bace8931 ("powercap/drivers/dtpm: Scale the power with the load") Signed-off-by: Sivan Zohar-Kotzer sivany32@gmail.com Link: https://patch.msgid.link/20250701221355.96916-1-sivany32@gmail.com [ rjw: Drop an excess empty code line ] Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/powercap/dtpm_cpu.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/drivers/powercap/dtpm_cpu.c b/drivers/powercap/dtpm_cpu.c index ae7ee611978b..99a82060ead9 100644 --- a/drivers/powercap/dtpm_cpu.c +++ b/drivers/powercap/dtpm_cpu.c @@ -93,6 +93,8 @@ static u64 get_pd_power_uw(struct dtpm *dtpm) int i;
pd = em_cpu_get(dtpm_cpu->cpu); + if (!pd) + return 0;
pd_mask = em_span_cpus(pd);