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

JIRA: https://issues.redhat.com/browse/RHEL-79553

commit 583ef25
Author: Dmitry Kandybka <[email protected]>
Date:   Fri Jan 24 01:07:39 2025 +0300

    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 <[email protected]>
    Reviewed-by: Rajneesh Bhardwaj <[email protected]>
    Reviewed-by: Ilpo Järvinen <[email protected]>
    Link: https://lore.kernel.org/r/[email protected]
    Signed-off-by: Ilpo Järvinen <[email protected]>

Signed-off-by: David Arcari <[email protected]>

Author: darcari

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;