hwmon: (coretemp) Set nr_cores only after core_data allocation succeeds

In init_temp_data(), pdata->nr_cores is populated from
topology_num_cores_per_package() before allocating pdata->core_data. If
that allocation fails, init_temp_data() returns NULL with
pdata->core_data still NULL and pdata->nr_cores set to a positive value.

coretemp_add_core() logs the error without failing coretemp_cpu_online(),
so the CPU still comes online with pdata->hwmon_dev registered. When the
CPU is later taken offline (or the module is unloaded),
coretemp_cpu_offline() calls get_temp_data(pd, cpu), which loops up to
pdata->nr_cores and dereferences the NULL pdata->core_data pointer.

Store the core count in a local variable and assign pdata->nr_cores only
after pdata->core_data is allocated, preserving the invariant that
pdata->nr_cores is zero whenever pdata->core_data is NULL.

Reported-by: Sashiko <sashiko-bot@kernel.org>
Fixes: 1a793caf6f69 ("hwmon: (coretemp) Use dynamic allocated memory for core temp_data")
Cc: stable@vger.kernel.org
Tested-by: Asaf Nuri Bertizlioğlu <ycistak@gmail.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

0 files changed, 0 insertions, 0 deletions