From: "Ahmed S. Darwish" <darwi@xxxxxxxxxxxxx> [ Upstream commit cf96ab1a966b87b09fdd9e8cc8357d2d00776a3a ] Protect against the kcpuid code parsing faulty max subleaf numbers through a min() expression. Thus, ensuring that max_subleaf will always be ≤ MAX_SUBLEAF_NUM. Use "u32" for the subleaf numbers since kcpuid is compiled with -Wextra, which includes signed/unsigned comparisons warnings. Signed-off-by: Ahmed S. Darwish <darwi@xxxxxxxxxxxxx> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Link: https://lore.kernel.org/all/20240718134755.378115-5-darwi@xxxxxxxxxxxxx Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- tools/arch/x86/kcpuid/kcpuid.c | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-) diff --git a/tools/arch/x86/kcpuid/kcpuid.c b/tools/arch/x86/kcpuid/kcpuid.c index 24b7d017ec2c1..b7965dfff33a9 100644 --- a/tools/arch/x86/kcpuid/kcpuid.c +++ b/tools/arch/x86/kcpuid/kcpuid.c @@ -7,7 +7,8 @@ #include <string.h> #include <getopt.h> -#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0])) +#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0])) +#define min(a, b) (((a) < (b)) ? (a) : (b)) typedef unsigned int u32; typedef unsigned long long u64; @@ -207,12 +208,9 @@ static void raw_dump_range(struct cpuid_range *range) #define MAX_SUBLEAF_NUM 32 struct cpuid_range *setup_cpuid_range(u32 input_eax) { - u32 max_func, idx_func; - int subleaf; + u32 max_func, idx_func, subleaf, max_subleaf; + u32 eax, ebx, ecx, edx, f = input_eax; struct cpuid_range *range; - u32 eax, ebx, ecx, edx; - u32 f = input_eax; - int max_subleaf; bool allzero; eax = input_eax; @@ -258,7 +256,7 @@ struct cpuid_range *setup_cpuid_range(u32 input_eax) * others have to be tried (0xf) */ if (f == 0x7 || f == 0x14 || f == 0x17 || f == 0x18) - max_subleaf = (eax & 0xff) + 1; + max_subleaf = min((eax & 0xff) + 1, max_subleaf); if (f == 0xb) max_subleaf = 2; -- 2.43.0
