platform/x86/intel: pmc: fix ltr decode in pmc_core_ltr_show()

In pmc_core_ltr_show(), promote 'val' to 'u64' to avoid possible integer
overflow. Values (10 bit) are multiplied by the scale, the result of
expression is in a range from 1 to 34,326,183,936 which is bigger then
UINT32_MAX. Compile tested only.

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

Signed-off-by: Dmitry Kandybka <d.kandybka@gmail.com>
Reviewed-by: Rajneesh Bhardwaj <irenic.rajneesh@gmail.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20250123220739.68087-1-d.kandybka@gmail.com
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

diff --git a/drivers/platform/x86/intel/pmc/core.c b/drivers/platform/x86/intel/pmc/core.c
index 10f04b9441174cabb1ca625b149bbdd837e1c146..1ee0fb5f8250b846ff4eed6f363c5835ca3d04d6 100644 (file)
--- a/drivers/platform/x86/intel/pmc/core.c
+++ b/drivers/platform/x86/intel/pmc/core.c
@@ -626,8 +626,8 @@ static u32 convert_ltr_scale(u32 val)
 static int pmc_core_ltr_show(struct seq_file *s, void *unused)
 {
        struct pmc_dev *pmcdev = s->private;
-       u64 decoded_snoop_ltr, decoded_non_snoop_ltr;
-       u32 ltr_raw_data, scale, val;
+       u64 decoded_snoop_ltr, decoded_non_snoop_ltr, val;
+       u32 ltr_raw_data, scale;
        u16 snoop_ltr, nonsnoop_ltr;
        unsigned int i, index, ltr_index = 0;