From: Wei Li <liwei391@xxxxxxxxxx> [ Upstream commit 1c41860864c8ae0387ef7d44f0000e99cbb2e06d ] When doing unwind_frame() in the context of pseudo nmi (need enable CONFIG_ARM64_PSEUDO_NMI), reaching the bottom of the stack (fp == 0, pc != 0), function on_sdei_stack() will return true while the sdei acpi table is not inited in fact. This will cause a "NULL pointer dereference" oops when going on. Reviewed-by: Julien Thierry <julien.thierry@xxxxxxx> Signed-off-by: Wei Li <liwei391@xxxxxxxxxx> Signed-off-by: Catalin Marinas <catalin.marinas@xxxxxxx> Signed-off-by: Sasha Levin (Microsoft) <sashal@xxxxxxxxxx> --- arch/arm64/kernel/sdei.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/arch/arm64/kernel/sdei.c b/arch/arm64/kernel/sdei.c index 5ba4465e44f0..ea94cf8f9dc6 100644 --- a/arch/arm64/kernel/sdei.c +++ b/arch/arm64/kernel/sdei.c @@ -94,6 +94,9 @@ static bool on_sdei_normal_stack(unsigned long sp, struct stack_info *info) unsigned long low = (unsigned long)raw_cpu_read(sdei_stack_normal_ptr); unsigned long high = low + SDEI_STACK_SIZE; + if (!low) + return false; + if (sp < low || sp >= high) return false; @@ -111,6 +114,9 @@ static bool on_sdei_critical_stack(unsigned long sp, struct stack_info *info) unsigned long low = (unsigned long)raw_cpu_read(sdei_stack_critical_ptr); unsigned long high = low + SDEI_STACK_SIZE; + if (!low) + return false; + if (sp < low || sp >= high) return false; -- 2.19.1
