5.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Armin Wolf <W_Armin@xxxxxx>
[ Upstream commit f6f172dc6a6d7775b2df6adfd1350700e9a847ec ]
When a multi-byte address space access is requested, acpi_ec_read()/
acpi_ec_write() is being called multiple times.
Abort such operations if a single call to acpi_ec_read() /
acpi_ec_write() fails, as the data read from / written to the EC
might be incomplete.
Signed-off-by: Armin Wolf <W_Armin@xxxxxx>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/acpi/ec.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
index c7baccd47b89f..43a8941b6743d 100644
--- a/drivers/acpi/ec.c
+++ b/drivers/acpi/ec.c
@@ -1310,10 +1310,13 @@ acpi_ec_space_handler(u32 function, acpi_physical_address address,
if (ec->busy_polling || bits > 8)
acpi_ec_burst_enable(ec);
- for (i = 0; i < bytes; ++i, ++address, ++value)
+ for (i = 0; i < bytes; ++i, ++address, ++value) {
result = (function == ACPI_READ) ?
acpi_ec_read(ec, address, value) :
acpi_ec_write(ec, address, *value);
+ if (result < 0)
+ break;
+ }
if (ec->busy_polling || bits > 8)
acpi_ec_burst_disable(ec);
--
2.43.0
