[PATCH RFC v2 0/6] staging: comedi: fix user/kernel space access of cmd->chanlist
Ian Abbott
abbotti at mev.co.uk
Tue Sep 18 19:26:59 UTC 2012
On 2012-09-18 20:12, Dan Carpenter wrote:
> This introduces some new Sparse warnings in the compat code.
>
> CHECK drivers/staging/comedi/comedi_compat32.c
> drivers/staging/comedi/comedi_compat32.c:212:16: warning: cast removes address space of expression
> drivers/staging/comedi/comedi_compat32.c:212:16: warning: cast removes address space of expression
> drivers/staging/comedi/comedi_compat32.c:212:16: warning: cast removes address space of expression
> drivers/staging/comedi/comedi_compat32.c:212:16: warning: cast removes address space of expression
> CC [M] drivers/staging/comedi/comedi_compat32.o
>
> 210 err |= __put_user(temp.uint, &cmd->stop_arg);
> 211 err |= __get_user(temp.uptr, &cmd32->chanlist);
> 212 err |= __put_user(compat_ptr(temp.uptr), &cmd->chanlist);
> 213 err |= __get_user(temp.uint, &cmd32->chanlist_len);
> 214 err |= __put_user(temp.uint, &cmd->chanlist_len);
> 215 err |= __get_user(temp.uptr, &cmd32->data);
> 216 err |= __put_user(compat_ptr(temp.uptr), &cmd->data);
> 217 err |= __get_user(temp.uint, &cmd32->data_len);
>
> I'm not sure how to cast away the warnings...
You'd need a shadow of the `struct comedi_cmd` that tags the `chanlist`
pointer tagged as `__user`. I've been there!
--
-=( Ian Abbott @ MEV Ltd. E-mail: <abbotti at mev.co.uk> )=-
-=( Tel: +44 (0)161 477 1898 FAX: +44 (0)161 718 3587 )=-
More information about the devel
mailing list