From: Mark Rutland mark.rutland@arm.com
commit 71c751f2a43fa03fae3cf5f0067ed3001a397013 upstream.
We're missing a sentinel entry in kpti_safe_list. Thus is_midr_in_range_list() can walk past the end of kpti_safe_list. Depending on the contents of memory, this could erroneously match a CPU's MIDR, cause a data abort, or other bad outcomes.
Add the sentinel entry to avoid this.
Fixes: be5b299830c63ed7 ("arm64: capabilities: Add support for checks based on a list of MIDRs") Signed-off-by: Mark Rutland mark.rutland@arm.com Reported-by: Jan Kiszka jan.kiszka@siemens.com Tested-by: Jan Kiszka jan.kiszka@siemens.com Reviewed-by: Suzuki K Poulose suzuki.poulose@arm.com Cc: Catalin Marinas catalin.marinas@arm.com Cc: Suzuki K Poulose suzuki.poulose@arm.com Cc: Will Deacon will.deacon@arm.com Signed-off-by: Will Deacon will.deacon@arm.com Signed-off-by: Juerg Haefliger juergh@canonical.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/arm64/kernel/cpufeature.c | 1 + 1 file changed, 1 insertion(+)
--- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -836,6 +836,7 @@ static bool unmap_kernel_at_el0(const st MIDR_ALL_VERSIONS(MIDR_CORTEX_A57), MIDR_ALL_VERSIONS(MIDR_CORTEX_A72), MIDR_ALL_VERSIONS(MIDR_CORTEX_A73), + { /* sentinel */ } }; char const *str = "kpti command line option"; bool meltdown_safe;