[PATCH] x86: hpet: Fix to avoid potential NULL pointer dereference

[Aditya Pakki]

hpet_virt_address may be NULL when ioremap_nocache fails. The patch
checks for such a scenario and avoids NULL pointer dereference.

Signed-off-by: Aditya Pakki <pakki...@umn.edu>
---
 arch/x86/kernel/hpet.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c
index dfd3aca82c61..fb32925a2e62 100644
--- a/arch/x86/kernel/hpet.c
+++ b/arch/x86/kernel/hpet.c
@@ -905,6 +905,8 @@ int __init hpet_enable(void)
                return 0;
 
        hpet_set_mapping();
+       if (!hpet_virt_address)
+               return 0;
 
        /*
         * Read the period and check for a sane value:
-- 
2.17.1