| From 10a16997db3d99fc02c026cf2c6e6c670acafab0 Mon Sep 17 00:00:00 2001 |
| From: "Dmitry V. Levin" <ldv@altlinux.org> |
| Date: Fri, 29 Mar 2019 20:12:21 +0300 |
| Subject: riscv: Fix syscall_get_arguments() and syscall_set_arguments() |
| |
| From: Dmitry V. Levin <ldv@altlinux.org> |
| |
| commit 10a16997db3d99fc02c026cf2c6e6c670acafab0 upstream. |
| |
| RISC-V syscall arguments are located in orig_a0,a1..a5 fields |
| of struct pt_regs. |
| |
| Due to an off-by-one bug and a bug in pointer arithmetic |
| syscall_get_arguments() was reading s3..s7 fields instead of a1..a5. |
| Likewise, syscall_set_arguments() was writing s3..s7 fields |
| instead of a1..a5. |
| |
| Link: http://lkml.kernel.org/r/20190329171221.GA32456@altlinux.org |
| |
| Fixes: e2c0cdfba7f69 ("RISC-V: User-facing API") |
| 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: Albert Ou <aou@eecs.berkeley.edu> |
| Cc: linux-riscv@lists.infradead.org |
| Cc: stable@vger.kernel.org # v4.15+ |
| Acked-by: Palmer Dabbelt <palmer@sifive.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/riscv/include/asm/syscall.h | 12 +++++++----- |
| 1 file changed, 7 insertions(+), 5 deletions(-) |
| |
| --- a/arch/riscv/include/asm/syscall.h |
| +++ b/arch/riscv/include/asm/syscall.h |
| @@ -79,10 +79,11 @@ static inline void syscall_get_arguments |
| 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 syscall_set_arguments(struct task_struct *task, |
| @@ -94,10 +95,11 @@ static inline void syscall_set_arguments |
| if (i == 0) { |
| regs->orig_a0 = args[0]; |
| args++; |
| - i++; |
| n--; |
| - } |
| - memcpy(®s->a1 + i * sizeof(regs->a1), args, n * sizeof(regs->a0)); |
| + } else { |
| + i--; |
| + } |
| + memcpy(®s->a1 + i, args, n * sizeof(regs->a1)); |
| } |
| |
| static inline int syscall_get_arch(void) |