On Mon, Jun 19, 2023 at 01:35:35PM +0100, Ben Dooks wrote:
> The two syscalls for capget and capset are producing sparse warnings
> as sparse is thinking that the "struct __user_cap_data_struct" is marked
> user, which seems to be down to the declaration and typedef at the same
> time.
>
> Fix the following warnings by splutting the struct declaration and then
> the user typedef into two:
I'm not a fan of making code changes to work around scanners'
shortcomings, mainly because eventually I assume the scanners
will learn to deal with it.
However, I don't like the all-in-one typedef+struct definition
either, so let's go with it :)
Paul, do you mind picking this up?
thanks,
-serge
> kernel/capability.c:191:35: warning: incorrect type in argument 2 (different address spaces)
> kernel/capability.c:191:35: expected void const *from
> kernel/capability.c:191:35: got struct __user_cap_data_struct [noderef] __user *
> kernel/capability.c:168:14: warning: dereference of noderef expression
> kernel/capability.c:168:45: warning: dereference of noderef expression
> kernel/capability.c:169:14: warning: dereference of noderef expression
> kernel/capability.c:169:45: warning: dereference of noderef expression
> kernel/capability.c:170:14: warning: dereference of noderef expression
> kernel/capability.c:170:45: warning: dereference of noderef expression
> kernel/capability.c:244:29: warning: incorrect type in argument 1 (different address spaces)
> kernel/capability.c:244:29: expected void *to
> kernel/capability.c:244:29: got struct __user_cap_data_struct [noderef] __user ( * )[2]
> kernel/capability.c:247:42: warning: dereference of noderef expression
> kernel/capability.c:247:64: warning: dereference of noderef expression
> kernel/capability.c:248:42: warning: dereference of noderef expression
> kernel/capability.c:248:64: warning: dereference of noderef expression
> kernel/capability.c:249:42: warning: dereference of noderef expression
> kernel/capability.c:249:64: warning: dereference of noderef expression
>
> Signed-off-by: Ben Dooks <[email protected]>
Reviewed-by: Serge Hallyn <[email protected]>
> ---
> include/uapi/linux/capability.h | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/include/uapi/linux/capability.h b/include/uapi/linux/capability.h
> index 3d61a0ae055d..5bb906098697 100644
> --- a/include/uapi/linux/capability.h
> +++ b/include/uapi/linux/capability.h
> @@ -41,11 +41,12 @@ typedef struct __user_cap_header_struct {
> int pid;
> } __user *cap_user_header_t;
>
> -typedef struct __user_cap_data_struct {
> +struct __user_cap_data_struct {
> __u32 effective;
> __u32 permitted;
> __u32 inheritable;
> -} __user *cap_user_data_t;
> +};
> +typedef struct __user_cap_data_struct __user *cap_user_data_t;
>
>
> #define VFS_CAP_REVISION_MASK 0xFF000000
> --
> 2.39.2
On Mon, Jun 19, 2023 at 1:57 PM Serge E. Hallyn <[email protected]> wrote:
>
> On Mon, Jun 19, 2023 at 01:35:35PM +0100, Ben Dooks wrote:
> > The two syscalls for capget and capset are producing sparse warnings
> > as sparse is thinking that the "struct __user_cap_data_struct" is marked
> > user, which seems to be down to the declaration and typedef at the same
> > time.
> >
> > Fix the following warnings by splutting the struct declaration and then
> > the user typedef into two:
>
> I'm not a fan of making code changes to work around scanners'
> shortcomings, mainly because eventually I assume the scanners
> will learn to deal with it.
>
> However, I don't like the all-in-one typedef+struct definition
> either, so let's go with it :)
>
> Paul, do you mind picking this up?
Sure, no problem. Since we are at -rc7, I'm assuming this can wait
until after the merge window?
--
paul-moore.com
On Mon, Jun 19, 2023 at 05:47:54PM -0400, Paul Moore wrote:
> On Mon, Jun 19, 2023 at 1:57 PM Serge E. Hallyn <[email protected]> wrote:
> >
> > On Mon, Jun 19, 2023 at 01:35:35PM +0100, Ben Dooks wrote:
> > > The two syscalls for capget and capset are producing sparse warnings
> > > as sparse is thinking that the "struct __user_cap_data_struct" is marked
> > > user, which seems to be down to the declaration and typedef at the same
> > > time.
> > >
> > > Fix the following warnings by splutting the struct declaration and then
> > > the user typedef into two:
> >
> > I'm not a fan of making code changes to work around scanners'
> > shortcomings, mainly because eventually I assume the scanners
> > will learn to deal with it.
> >
> > However, I don't like the all-in-one typedef+struct definition
> > either, so let's go with it :)
> >
> > Paul, do you mind picking this up?
>
> Sure, no problem. Since we are at -rc7, I'm assuming this can wait
> until after the merge window?
Yeah, it's just fixing a sparse warning, no urgency.
thanks,
-serge
On Wed, Jun 21, 2023 at 9:43 AM Serge Hallyn <[email protected]> wrote:
> On Mon, Jun 19, 2023 at 05:47:54PM -0400, Paul Moore wrote:
> > On Mon, Jun 19, 2023 at 1:57 PM Serge E. Hallyn <[email protected]> wrote:
> > >
> > > On Mon, Jun 19, 2023 at 01:35:35PM +0100, Ben Dooks wrote:
> > > > The two syscalls for capget and capset are producing sparse warnings
> > > > as sparse is thinking that the "struct __user_cap_data_struct" is marked
> > > > user, which seems to be down to the declaration and typedef at the same
> > > > time.
> > > >
> > > > Fix the following warnings by splutting the struct declaration and then
> > > > the user typedef into two:
> > >
> > > I'm not a fan of making code changes to work around scanners'
> > > shortcomings, mainly because eventually I assume the scanners
> > > will learn to deal with it.
> > >
> > > However, I don't like the all-in-one typedef+struct definition
> > > either, so let's go with it :)
> > >
> > > Paul, do you mind picking this up?
> >
> > Sure, no problem. Since we are at -rc7, I'm assuming this can wait
> > until after the merge window?
>
> Yeah, it's just fixing a sparse warning, no urgency.
Actually, this looks like a dup of 55382134366e ("capability: erase
checker warnings about struct __user_cap_data_struct") which is
currently in Linus' tree.
Thank you for your patch Ben, but it looks as if we had a patch a
couple of weeks before yours which fixed the same problem. If you
notice continuing problems with the latest kernel sources from Linus
please let us know.
--
paul-moore.com