acpi/arm64: Adjust error handling procedure in gtdt_parse_timer_block()

In case of error in gtdt_parse_timer_block() invalid 'gtdt_frame'
will be used in 'do {} while (i-- >= 0 && gtdt_frame--);' statement block
because do{} block will be executed even if 'i == 0'.

Adjust error handling procedure by replacing 'i-- >= 0' with 'i-- > 0'.

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

Fixes: a712c3ed9b8a ("acpi/arm64: Add memory-mapped timer support in GTDT driver")
Signed-off-by: Aleksandr Mishin <amishin@t-argos.ru>
Acked-by: Hanjun Guo <guohanjun@huawei.com>
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Aleksandr Mishin <amishin@t-argos.ru>
Link: https://lore.kernel.org/r/20240827101239.22020-1-amishin@t-argos.ru
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

diff --git a/drivers/acpi/arm64/gtdt.c b/drivers/acpi/arm64/gtdt.c
index d7c4e1b9915b4065747cb6e38dcca89eee3f44ac..81dc0582743df5a679774232221e90c114c06674 100644 (file)
--- a/drivers/acpi/arm64/gtdt.c
+++ b/drivers/acpi/arm64/gtdt.c
@@ -294,7 +294,7 @@ error:
                if (frame->virt_irq > 0)
                        acpi_unregister_gsi(gtdt_frame->virtual_timer_interrupt);
                frame->virt_irq = 0;
-       } while (i-- >= 0 && gtdt_frame--);
+       } while (i-- > 0 && gtdt_frame--);
 
        return -EINVAL;
 }