Re: [PATCH] score: fix off-by-one index into syscall table

[Lennox Wu]

Dear all,
I will look the issue and update the informaion  of  MAINTAINERS.
Best,
Lennox

2012/1/10 Eugene Teo <eugeneteo@xxxxxxxxx>
>
> On Tue, Jan 10, 2012 at 2:40 PM, Eugene Teo <eugeneteo@xxxxxxxxx> wrote:
> > Cc'ed arnd@xxxxxxxx
> >
> > ping
>
> Liqin's work email bounced.  I'm not sure if he is working on these
> anymore. If not, the MAINTAINERS file needs to be updated.
>
> > On Fri, Jan 6, 2012 at 9:21 PM, Dan Rosenberg <drosenberg@xxxxxxxxxxxxx> wrote:
> >> If the provided system call number is equal to __NR_syscalls, the
> >> current check will pass and a function pointer just after the system
> >> call table may be called, since sys_call_table is an array with total
> >> size __NR_syscalls.  Whether or not this is a security bug depends on
> >> what the compiler puts immediately after the system call table.  It's
> >> likely that this won't do anything bad because there is an additional
> >> NULL check on the syscall entry, but if there happens to be a non-NULL
> >> value immediately after the system call table, this may result in local
> >> privilege escalation.
> >>
> >> Signed-off-by: Dan Rosenberg <drosenberg@xxxxxxxxxxxxx>
> >> Cc: stable@xxxxxxxxxx
> >> Cc: security@xxxxxxxxxx
> >> ---
> >>  arch/score/kernel/entry.S |    2 +-
> >>  1 files changed, 1 insertions(+), 1 deletions(-)
> >>
> >> diff --git a/arch/score/kernel/entry.S b/arch/score/kernel/entry.S
> >> index 577abba..83bb960 100644
> >> --- a/arch/score/kernel/entry.S
> >> +++ b/arch/score/kernel/entry.S
> >> @@ -408,7 +408,7 @@ ENTRY(handle_sys)
> >>        sw      r9, [r0, PT_EPC]
> >>
> >>        cmpi.c  r27, __NR_syscalls      # check syscall number
> >> -       bgtu    illegal_syscall
> >> +       bgeu    illegal_syscall
> >>
> >>        slli    r8, r27, 2              # get syscall routine
> >>        la      r11, sys_call_table
> >>
> >>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/