| From ed3bb007021b9bddb90afae28a19f08ed8890add Mon Sep 17 00:00:00 2001 |
| From: "Dmitry V. Levin" <ldv@altlinux.org> |
| Date: Fri, 29 Mar 2019 20:12:30 +0300 |
| Subject: csky: Fix syscall_get_arguments() and syscall_set_arguments() |
| |
| From: Dmitry V. Levin <ldv@altlinux.org> |
| |
| commit ed3bb007021b9bddb90afae28a19f08ed8890add upstream. |
| |
| C-SKY syscall arguments are located in orig_a0,a1,a2,a3,regs[0],regs[1] |
| fields of struct pt_regs. |
| |
| Due to an off-by-one bug and a bug in pointer arithmetic |
| syscall_get_arguments() was reading orig_a0,regs[1..5] fields instead. |
| Likewise, syscall_set_arguments() was writing orig_a0,regs[1..5] fields |
| instead. |
| |
| Link: http://lkml.kernel.org/r/20190329171230.GB32456@altlinux.org |
| |
| Fixes: 4859bfca11c7d ("csky: System Call") |
| Cc: Ingo Molnar <mingo@redhat.com> |
| Cc: Kees Cook <keescook@chromium.org> |
| Cc: Andy Lutomirski <luto@amacapital.net> |
| Cc: Will Drewry <wad@chromium.org> |
| Cc: stable@vger.kernel.org # v4.20+ |
| Tested-by: Guo Ren <ren_guo@c-sky.com> |
| Acked-by: Guo Ren <ren_guo@c-sky.com> |
| Signed-off-by: Dmitry V. Levin <ldv@altlinux.org> |
| Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| arch/csky/include/asm/syscall.h | 10 ++++++---- |
| 1 file changed, 6 insertions(+), 4 deletions(-) |
| |
| --- a/arch/csky/include/asm/syscall.h |
| +++ b/arch/csky/include/asm/syscall.h |
| @@ -49,10 +49,11 @@ syscall_get_arguments(struct task_struct |
| if (i == 0) { |
| args[0] = regs->orig_a0; |
| args++; |
| - i++; |
| n--; |
| + } else { |
| + i--; |
| } |
| - memcpy(args, ®s->a1 + i * sizeof(regs->a1), n * sizeof(args[0])); |
| + memcpy(args, ®s->a1 + i, n * sizeof(args[0])); |
| } |
| |
| static inline void |
| @@ -63,10 +64,11 @@ syscall_set_arguments(struct task_struct |
| if (i == 0) { |
| regs->orig_a0 = args[0]; |
| args++; |
| - i++; |
| n--; |
| + } else { |
| + i--; |
| } |
| - memcpy(®s->a1 + i * sizeof(regs->a1), args, n * sizeof(regs->a0)); |
| + memcpy(®s->a1 + i, args, n * sizeof(regs->a1)); |
| } |
| |
| static inline int |