* [PATCH] csky: fix syscall_get_arguments() and syscall_set_arguments()
@ 2019-03-29 17:12 Dmitry V. Levin
2019-03-30 0:49 ` Guo Ren
0 siblings, 1 reply; 2+ messages in thread
From: Dmitry V. Levin @ 2019-03-29 17:12 UTC (permalink / raw)
To: Guo Ren
Cc: Steven Rostedt, Ingo Molnar, Kees Cook, Andy Lutomirski,
Will Drewry, linux-kernel
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.
Fixes: 4859bfca11c7d ("csky: System Call")
Cc: Steven Rostedt <rostedt@goodmis.org>
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+
Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
---
arch/csky/include/asm/syscall.h | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/arch/csky/include/asm/syscall.h b/arch/csky/include/asm/syscall.h
index d637445737b7..9a9cd81e66c1 100644
--- a/arch/csky/include/asm/syscall.h
+++ b/arch/csky/include/asm/syscall.h
@@ -49,10 +49,11 @@ syscall_get_arguments(struct task_struct *task, struct pt_regs *regs,
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 *task, struct pt_regs *regs,
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
--
ldv
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] csky: fix syscall_get_arguments() and syscall_set_arguments()
2019-03-29 17:12 [PATCH] csky: fix syscall_get_arguments() and syscall_set_arguments() Dmitry V. Levin
@ 2019-03-30 0:49 ` Guo Ren
0 siblings, 0 replies; 2+ messages in thread
From: Guo Ren @ 2019-03-30 0:49 UTC (permalink / raw)
To: Dmitry V. Levin
Cc: Steven Rostedt, Ingo Molnar, Kees Cook, Andy Lutomirski,
Will Drewry, linux-kernel
Thx Dmitry,
It works for me.
Tested-by: Guo Ren <ren_guo@c-sky.com>
Acked-by: Guo Ren <ren_guo@c-sky.com>
On Fri, Mar 29, 2019 at 08:12:30PM +0300, Dmitry V. Levin wrote:
> 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.
>
> Fixes: 4859bfca11c7d ("csky: System Call")
> Cc: Steven Rostedt <rostedt@goodmis.org>
> 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+
> Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
> ---
> arch/csky/include/asm/syscall.h | 10 ++++++----
> 1 file changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/arch/csky/include/asm/syscall.h b/arch/csky/include/asm/syscall.h
> index d637445737b7..9a9cd81e66c1 100644
> --- a/arch/csky/include/asm/syscall.h
> +++ b/arch/csky/include/asm/syscall.h
> @@ -49,10 +49,11 @@ syscall_get_arguments(struct task_struct *task, struct pt_regs *regs,
> 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 *task, struct pt_regs *regs,
> 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
> --
> ldv
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2019-03-30 0:49 ` Guo Ren
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