From: Sami Tolvanen <samitolvanen@xxxxxxxxxx> commit f48f01a92cca09e86d46c91d8edf9d5a71c61727 upstream. Use the correct function type for sys_ni_syscall() in system call tables to fix indirect call mismatches with Control-Flow Integrity (CFI) checking. Signed-off-by: Sami Tolvanen <samitolvanen@xxxxxxxxxx> Acked-by: Andy Lutomirski <luto@xxxxxxxxxx> Cc: Borislav Petkov <bp@xxxxxxxxx> Cc: H . Peter Anvin <hpa@xxxxxxxxx> Cc: Kees Cook <keescook@xxxxxxxxxxxx> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Link: https://lkml.kernel.org/r/20191008224049.115427-5-samitolvanen@xxxxxxxxxx Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/x86/entry/syscall_32.c | 8 +++----- arch/x86/entry/syscall_64.c | 14 ++++++++++---- arch/x86/entry/syscalls/syscall_32.tbl | 4 ++-- 3 files changed, 15 insertions(+), 11 deletions(-) --- a/arch/x86/entry/syscall_32.c +++ b/arch/x86/entry/syscall_32.c @@ -10,13 +10,11 @@ #ifdef CONFIG_IA32_EMULATION /* On X86_64, we use struct pt_regs * to pass parameters to syscalls */ #define __SYSCALL_I386(nr, sym, qual) extern asmlinkage long sym(const struct pt_regs *); - -/* this is a lie, but it does not hurt as sys_ni_syscall just returns -EINVAL */ -extern asmlinkage long sys_ni_syscall(const struct pt_regs *); - +#define __sys_ni_syscall __ia32_sys_ni_syscall #else /* CONFIG_IA32_EMULATION */ #define __SYSCALL_I386(nr, sym, qual) extern asmlinkage long sym(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long); extern asmlinkage long sys_ni_syscall(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long); +#define __sys_ni_syscall sys_ni_syscall #endif /* CONFIG_IA32_EMULATION */ #include <asm/syscalls_32.h> @@ -29,6 +27,6 @@ __visible const sys_call_ptr_t ia32_sys_ * Smells like a compiler bug -- it doesn't work * when the & below is removed. */ - [0 ... __NR_syscall_compat_max] = &sys_ni_syscall, + [0 ... __NR_syscall_compat_max] = &__sys_ni_syscall, #include <asm/syscalls_32.h> }; --- a/arch/x86/entry/syscall_64.c +++ b/arch/x86/entry/syscall_64.c @@ -4,11 +4,17 @@ #include <linux/linkage.h> #include <linux/sys.h> #include <linux/cache.h> +#include <linux/syscalls.h> #include <asm/asm-offsets.h> #include <asm/syscall.h> -/* this is a lie, but it does not hurt as sys_ni_syscall just returns -EINVAL */ -extern asmlinkage long sys_ni_syscall(const struct pt_regs *); +extern asmlinkage long sys_ni_syscall(void); + +SYSCALL_DEFINE0(ni_syscall) +{ + return sys_ni_syscall(); +} + #define __SYSCALL_64(nr, sym, qual) extern asmlinkage long sym(const struct pt_regs *); #define __SYSCALL_X32(nr, sym, qual) __SYSCALL_64(nr, sym, qual) #include <asm/syscalls_64.h> @@ -23,7 +29,7 @@ asmlinkage const sys_call_ptr_t sys_call * Smells like a compiler bug -- it doesn't work * when the & below is removed. */ - [0 ... __NR_syscall_max] = &sys_ni_syscall, + [0 ... __NR_syscall_max] = &__x64_sys_ni_syscall, #include <asm/syscalls_64.h> }; @@ -40,7 +46,7 @@ asmlinkage const sys_call_ptr_t x32_sys_ * Smells like a compiler bug -- it doesn't work * when the & below is removed. */ - [0 ... __NR_syscall_x32_max] = &sys_ni_syscall, + [0 ... __NR_syscall_x32_max] = &__x64_sys_ni_syscall, #include <asm/syscalls_64.h> }; --- a/arch/x86/entry/syscalls/syscall_32.tbl +++ b/arch/x86/entry/syscalls/syscall_32.tbl @@ -124,7 +124,7 @@ 110 i386 iopl sys_iopl __ia32_sys_iopl 111 i386 vhangup sys_vhangup __ia32_sys_vhangup 112 i386 idle -113 i386 vm86old sys_vm86old sys_ni_syscall +113 i386 vm86old sys_vm86old __ia32_sys_ni_syscall 114 i386 wait4 sys_wait4 __ia32_compat_sys_wait4 115 i386 swapoff sys_swapoff __ia32_sys_swapoff 116 i386 sysinfo sys_sysinfo __ia32_compat_sys_sysinfo @@ -177,7 +177,7 @@ 163 i386 mremap sys_mremap __ia32_sys_mremap 164 i386 setresuid sys_setresuid16 __ia32_sys_setresuid16 165 i386 getresuid sys_getresuid16 __ia32_sys_getresuid16 -166 i386 vm86 sys_vm86 sys_ni_syscall +166 i386 vm86 sys_vm86 __ia32_sys_ni_syscall 167 i386 query_module 168 i386 poll sys_poll __ia32_sys_poll 169 i386 nfsservctl
