diff mbox series

[3/6,v3] riscv: Fix syscall_get_arguments() and syscall_set_arguments()

Message ID 20190401134420.958530155@goodmis.org (mailing list archive)
State New, archived
Headers show
Series None | expand

Commit Message

Steven Rostedt April 1, 2019, 1:41 p.m. UTC 
From: "Dmitry V. Levin" <ldv@altlinux.org>

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: Palmer Dabbelt <palmer@sifive.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: linux-riscv@lists.infradead.org
Cc: stable@vger.kernel.org # v4.15+
Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 arch/riscv/include/asm/syscall.h | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

Comments

Dmitry V. Levin April 4, 2019, 2:02 p.m. UTC | #1 
On Mon, Apr 01, 2019 at 09:41:07AM -0400, Steven Rostedt wrote:
> From: "Dmitry V. Levin" <ldv@altlinux.org>
> 
> 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: Palmer Dabbelt <palmer@sifive.com>
> Cc: Albert Ou <aou@eecs.berkeley.edu>
> Cc: linux-riscv@lists.infradead.org
> Cc: stable@vger.kernel.org # v4.15+
> Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

According to
https://lore.kernel.org/lkml/mhng-8e9b547b-7fe3-43d2-9dea-b217de923605@palmer-si-x1c4/
the following tag could be added to this patch:
 
Acked-by: Palmer Dabbelt <palmer@sifive.com>
Steven Rostedt April 4, 2019, 2:26 p.m. UTC | #2 
On Thu, 4 Apr 2019 17:02:10 +0300
"Dmitry V. Levin" <ldv@altlinux.org> wrote:

> On Mon, Apr 01, 2019 at 09:41:07AM -0400, Steven Rostedt wrote:
> > From: "Dmitry V. Levin" <ldv@altlinux.org>
> > 
> > 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: Palmer Dabbelt <palmer@sifive.com>
> > Cc: Albert Ou <aou@eecs.berkeley.edu>
> > Cc: linux-riscv@lists.infradead.org
> > Cc: stable@vger.kernel.org # v4.15+
> > Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
> > Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>  
> 
> According to
> https://lore.kernel.org/lkml/mhng-8e9b547b-7fe3-43d2-9dea-b217de923605@palmer-si-x1c4/
> the following tag could be added to this patch:
>  
> Acked-by: Palmer Dabbelt <palmer@sifive.com>

That link isn't actually an ack. Palmer, you OK if I add it?

-- Steve
Palmer Dabbelt April 4, 2019, 11:29 p.m. UTC | #3 
On Thu, 04 Apr 2019 07:26:53 PDT (-0700), rostedt@goodmis.org wrote:
> On Thu, 4 Apr 2019 17:02:10 +0300
> "Dmitry V. Levin" <ldv@altlinux.org> wrote:
>
>> On Mon, Apr 01, 2019 at 09:41:07AM -0400, Steven Rostedt wrote:
>> > From: "Dmitry V. Levin" <ldv@altlinux.org>
>> >
>> > 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: Palmer Dabbelt <palmer@sifive.com>
>> > Cc: Albert Ou <aou@eecs.berkeley.edu>
>> > Cc: linux-riscv@lists.infradead.org
>> > Cc: stable@vger.kernel.org # v4.15+
>> > Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
>> > Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
>>
>> According to
>> https://lore.kernel.org/lkml/mhng-8e9b547b-7fe3-43d2-9dea-b217de923605@palmer-si-x1c4/
>> the following tag could be added to this patch:
>>
>> Acked-by: Palmer Dabbelt <palmer@sifive.com>
>
> That link isn't actually an ack. Palmer, you OK if I add it?

Acked-by: Palmer Dabbelt <palmer@sifive.com> (for the RISC-V parts)

Thanks!
diff mbox series

Patch

diff --git a/arch/riscv/include/asm/syscall.h b/arch/riscv/include/asm/syscall.h
index bba3da6ef157..6ea9e1804233 100644
--- a/arch/riscv/include/asm/syscall.h
+++ b/arch/riscv/include/asm/syscall.h
@@ -79,10 +79,11 @@  static inline void syscall_get_arguments(struct task_struct *task,
 	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 syscall_set_arguments(struct task_struct *task,
@@ -94,10 +95,11 @@  static inline void syscall_set_arguments(struct task_struct *task,
         if (i == 0) {
                 regs->orig_a0 = args[0];
                 args++;
-                i++;
                 n--;
-        }
-	memcpy(&regs->a1 + i * sizeof(regs->a1), args, n * sizeof(regs->a0));
+	} else {
+		i--;
+	}
+	memcpy(&regs->a1 + i, args, n * sizeof(regs->a1));
 }
 
 static inline int syscall_get_arch(void)