2019-04-01 13:45:56

by Steven Rostedt

[permalink] [raw]
Subject: [PATCH 4/6 v3] csky: Fix syscall_get_arguments() and syscall_set_arguments()

From: "Dmitry V. Levin" <[email protected]>

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/[email protected]

Fixes: 4859bfca11c7d ("csky: System Call")
Cc: Ingo Molnar <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Will Drewry <[email protected]>
Cc: Guo Ren <[email protected]>
Cc: [email protected] # v4.20+
Signed-off-by: Dmitry V. Levin <[email protected]>
Signed-off-by: Steven Rostedt (VMware) <[email protected]>
---
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, &regs->a1 + i * sizeof(regs->a1), n * sizeof(args[0]));
+ memcpy(args, &regs->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(&regs->a1 + i * sizeof(regs->a1), args, n * sizeof(regs->a0));
+ memcpy(&regs->a1 + i, args, n * sizeof(regs->a1));
}

static inline int
--
2.20.1



2019-04-04 14:03:07

by Dmitry V. Levin

[permalink] [raw]
Subject: Re: [PATCH 4/6 v3] csky: Fix syscall_get_arguments() and syscall_set_arguments()

On Mon, Apr 01, 2019 at 09:41:08AM -0400, Steven Rostedt wrote:
> From: "Dmitry V. Levin" <[email protected]>
>
> 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/[email protected]
>
> Fixes: 4859bfca11c7d ("csky: System Call")
> Cc: Ingo Molnar <[email protected]>
> Cc: Kees Cook <[email protected]>
> Cc: Andy Lutomirski <[email protected]>
> Cc: Will Drewry <[email protected]>
> Cc: Guo Ren <[email protected]>
> Cc: [email protected] # v4.20+
> Signed-off-by: Dmitry V. Levin <[email protected]>
> Signed-off-by: Steven Rostedt (VMware) <[email protected]>

According to
https://lore.kernel.org/lkml/20190330004949.GA15705@guoren-Inspiron-7460/
the following tags could be added to this patch:

Tested-by: Guo Ren <[email protected]>
Acked-by: Guo Ren <[email protected]>


--
ldv

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2019-04-04 14:29:00

by Steven Rostedt

[permalink] [raw]
Subject: Re: [PATCH 4/6 v3] csky: Fix syscall_get_arguments() and syscall_set_arguments()

On Thu, 4 Apr 2019 17:02:01 +0300
"Dmitry V. Levin" <[email protected]> wrote:
> According to
> https://lore.kernel.org/lkml/20190330004949.GA15705@guoren-Inspiron-7460/
> the following tags could be added to this patch:
>
> Tested-by: Guo Ren <[email protected]>
> Acked-by: Guo Ren <[email protected]>

Thanks! Added.

-- Steve