From: Aditya Pakki <pakki001@xxxxxxx> [ Upstream commit 2e84f116afca3719c9d0a1a78b47b48f75fd5724 ] hpet_virt_address may be NULL when ioremap_nocache fail, but the code lacks a check. Add a check to prevent NULL pointer dereference. Signed-off-by: Aditya Pakki <pakki001@xxxxxxx> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: kjlu@xxxxxxx Cc: Borislav Petkov <bp@xxxxxxxxx> Cc: "H. Peter Anvin" <hpa@xxxxxxxxx> Cc: Kees Cook <keescook@xxxxxxxxxxxx> Cc: Joe Perches <joe@xxxxxxxxxxx> Cc: Nicolai Stange <nstange@xxxxxxx> Cc: Roland Dreier <roland@xxxxxxxxxxxxxxx> Link: https://lkml.kernel.org/r/20190319021958.17275-1-pakki001@xxxxxxx Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- 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 319bcb9372fe..3e9c5725732f 100644 --- a/arch/x86/kernel/hpet.c +++ b/arch/x86/kernel/hpet.c @@ -799,6 +799,8 @@ 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: -- 2.19.1