Messages in this thread | | | Date | Mon, 19 Jun 2023 12:57:10 -0500 | From | "Serge E. Hallyn" <> | Subject | Re: [PATCH] capabilities: fix sparse warning about __user access |
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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 <ben.dooks@codethink.co.uk>
Reviewed-by: Serge Hallyn <serge@hallyn.com>
> --- > 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
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