| Message ID | 20230619123535.324632-1-ben.dooks@codethink.co.uk (mailing list archive) |
|---|---|
| State | In Next |
| Delegated to: | Paul Moore |
| Headers | show |
| Series | capabilities: fix sparse warning about __user access | expand |
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
On Mon, Jun 19, 2023 at 1:57 PM Serge E. Hallyn <serge@hallyn.com> 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?
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 <serge@hallyn.com> 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 <serge@hallyn.com> 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 <serge@hallyn.com> 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.
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
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: 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> --- include/uapi/linux/capability.h | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)