[PATCH AUTOSEL 4.14 008/109] ipmi:dmi: Ignore IPMI SMBIOS entries with a zero base address

[Sasha Levin]

From: Corey Minyard <cminyard@xxxxxxxxxx>

[ Upstream commit 1574608f5f4204440d6d9f52b971aba967664764 ]

Looking at logs from systems all over the place, it looks like tons
of broken systems exist that set the base address to zero.  I can
only guess that is some sort of non-standard idea to mark the
interface as not being present.  It can't be zero, anyway, so just
complain and ignore it.

Signed-off-by: Corey Minyard <cminyard@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/char/ipmi/ipmi_dmi.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/char/ipmi/ipmi_dmi.c b/drivers/char/ipmi/ipmi_dmi.c
index c3a23ec3e76f7..a37d9794170cc 100644
--- a/drivers/char/ipmi/ipmi_dmi.c
+++ b/drivers/char/ipmi/ipmi_dmi.c
@@ -197,6 +197,10 @@ static void __init dmi_decode_ipmi(const struct dmi_header *dm)
 	slave_addr = data[DMI_IPMI_SLAVEADDR];
 
 	memcpy(&base_addr, data + DMI_IPMI_ADDR, sizeof(unsigned long));
+	if (!base_addr) {
+		pr_err("Base address is zero, assuming no IPMI interface\n");
+		return;
+	}
 	if (len >= DMI_IPMI_VER2_LENGTH) {
 		if (type == IPMI_DMI_TYPE_SSIF) {
 			offset = 0;
-- 
2.20.1