The result of memremap() may be NULL on failure, leading to a NULL
dereference. Add explicit checks after memremap() call: if the
MADT mailbox fails to map, return immediately.
This is similar to the commit 966d47e1f27c
("efi: fix potential NULL deref in efi_mem_reserve_persistent").
This is found by our static analysis tool KNighter.
Signed-off-by: Chenyuan Yang <chenyuan0y@xxxxxxxxx>
Fixes: 2b5e22afae07 ("x86/acpi: Extract ACPI MADT wakeup code into a separate file")
---
arch/x86/kernel/acpi/madt_wakeup.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/arch/x86/kernel/acpi/madt_wakeup.c b/arch/x86/kernel/acpi/madt_wakeup.c
index f36f28405dcc..b386ec4b87c2 100644
--- a/arch/x86/kernel/acpi/madt_wakeup.c
+++ b/arch/x86/kernel/acpi/madt_wakeup.c
@@ -143,6 +143,10 @@ static int acpi_wakeup_cpu(u32 apicid, unsigned long start_ip)
acpi_mp_wake_mailbox = memremap(acpi_mp_wake_mailbox_paddr,
sizeof(*acpi_mp_wake_mailbox),
MEMREMAP_WB);
+ if (!acpi_mp_wake_mailbox) {
+ pr_err("Failed to remap MADT mailbox\n");
+ return -ENOMEM;
+ }
}
/*
--
2.34.1
