The permissions callback is not supposed to modify the ctl_table.
Enforce this expectation via the typesystem.
The patch was created with the following coccinelle script:
@@
identifier func, head, ctl;
@@
int func(
struct ctl_table_header *head,
- struct ctl_table *ctl)
+ const struct ctl_table *ctl)
{ ... }
(insert_entry() from fs/proc/proc_sysctl.c is a false-positive)
The three changed locations were validated through manually inspection
and compilation.
In addition a search for '.permissions =' was done over the full tree to
look for places that were missed by coccinelle.
None were found.
This change also is a step to put "struct ctl_table" into .rodata
throughout the kernel.
Signed-off-by: Thomas Weißschuh <[email protected]>
---
To: Luis Chamberlain <[email protected]>
To: Kees Cook <[email protected]>
To: Joel Granados <[email protected]>
To: David S. Miller <[email protected]>
Signed-off-by: Thomas Weißschuh <[email protected]>
Changes in v2:
- flesh out commit messages
- Integrate changes to set_ownership and ctl_table_args into a single
series
- Link to v1: https://lore.kernel.org/r/20231226-sysctl-const-permissions-v1-1-5cd3c91f6299@weissschuh.net
---
The patch is meant to be merged via the sysctl tree.
There is an upcoming series that will introduce a new implementation of
permission which would need to be adapted [0].
The adaption would be trivial as the 'table' parameter also not modified
there.
This change was originally part of the sysctl-const series [1].
To slim down that series and reduce the message load on other
maintainers to a minimumble, submit this patch on its own.
[0] https://lore.kernel.org/lkml/[email protected]/
[1] https://lore.kernel.org/lkml/[email protected]/
---
include/linux/sysctl.h | 2 +-
ipc/ipc_sysctl.c | 2 +-
kernel/ucount.c | 2 +-
net/sysctl_net.c | 2 +-
4 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h
index ee7d33b89e9e..0a55b5aade16 100644
--- a/include/linux/sysctl.h
+++ b/include/linux/sysctl.h
@@ -207,7 +207,7 @@ struct ctl_table_root {
void (*set_ownership)(struct ctl_table_header *head,
struct ctl_table *table,
kuid_t *uid, kgid_t *gid);
- int (*permissions)(struct ctl_table_header *head, struct ctl_table *table);
+ int (*permissions)(struct ctl_table_header *head, const struct ctl_table *table);
};
#define register_sysctl(path, table) \
diff --git a/ipc/ipc_sysctl.c b/ipc/ipc_sysctl.c
index 8c62e443f78b..b087787f608f 100644
--- a/ipc/ipc_sysctl.c
+++ b/ipc/ipc_sysctl.c
@@ -190,7 +190,7 @@ static int set_is_seen(struct ctl_table_set *set)
return ¤t->nsproxy->ipc_ns->ipc_set == set;
}
-static int ipc_permissions(struct ctl_table_header *head, struct ctl_table *table)
+static int ipc_permissions(struct ctl_table_header *head, const struct ctl_table *table)
{
int mode = table->mode;
diff --git a/kernel/ucount.c b/kernel/ucount.c
index 4aa6166cb856..90300840256b 100644
--- a/kernel/ucount.c
+++ b/kernel/ucount.c
@@ -38,7 +38,7 @@ static int set_is_seen(struct ctl_table_set *set)
}
static int set_permissions(struct ctl_table_header *head,
- struct ctl_table *table)
+ const struct ctl_table *table)
{
struct user_namespace *user_ns =
container_of(head->set, struct user_namespace, set);
diff --git a/net/sysctl_net.c b/net/sysctl_net.c
index 051ed5f6fc93..ba9a49de9600 100644
--- a/net/sysctl_net.c
+++ b/net/sysctl_net.c
@@ -40,7 +40,7 @@ static int is_seen(struct ctl_table_set *set)
/* Return standard mode bits for table entry. */
static int net_ctl_permissions(struct ctl_table_header *head,
- struct ctl_table *table)
+ const struct ctl_table *table)
{
struct net *net = container_of(head->set, struct net, sysctls);
---
base-commit: ffd2cb6b718e189e7e2d5d0c19c25611f92e061a
change-id: 20231226-sysctl-const-permissions-d7cfd02a7637
Best regards,
--
Thomas Weißschuh <[email protected]>
Hey Thomas
Just to be sure I'm following. This is V2 of "[PATCH] sysctl: treewide:
constify ctl_table_root::set_ownership". Right? I ask, because the
subject changes slightly.
Best
On Fri, Feb 23, 2024 at 04:52:16PM +0100, Thomas Wei?schuh wrote:
> The permissions callback is not supposed to modify the ctl_table.
> Enforce this expectation via the typesystem.
>
> The patch was created with the following coccinelle script:
>
> @@
> identifier func, head, ctl;
> @@
>
> int func(
> struct ctl_table_header *head,
> - struct ctl_table *ctl)
> + const struct ctl_table *ctl)
> { ... }
>
> (insert_entry() from fs/proc/proc_sysctl.c is a false-positive)
>
> The three changed locations were validated through manually inspection
> and compilation.
>
> In addition a search for '.permissions =' was done over the full tree to
> look for places that were missed by coccinelle.
> None were found.
>
> This change also is a step to put "struct ctl_table" into .rodata
> throughout the kernel.
>
> Signed-off-by: Thomas Wei?schuh <[email protected]>
> ---
> To: Luis Chamberlain <[email protected]>
> To: Kees Cook <[email protected]>
> To: Joel Granados <[email protected]>
> To: David S. Miller <[email protected]>
> Signed-off-by: Thomas Wei?schuh <[email protected]>
>
> Changes in v2:
> - flesh out commit messages
> - Integrate changes to set_ownership and ctl_table_args into a single
> series
> - Link to v1: https://lore.kernel.org/r/20231226-sysctl-const-permissions-v1-1-5cd3c91f6299@weissschuh.net
> ---
> The patch is meant to be merged via the sysctl tree.
>
> There is an upcoming series that will introduce a new implementation of
> .permission which would need to be adapted [0].
> The adaption would be trivial as the 'table' parameter also not modified
> there.
>
> This change was originally part of the sysctl-const series [1].
> To slim down that series and reduce the message load on other
> maintainers to a minimumble, submit this patch on its own.
>
> [0] https://lore.kernel.org/lkml/[email protected]/
> [1] https://lore.kernel.org/lkml/[email protected]/
> ---
> include/linux/sysctl.h | 2 +-
> ipc/ipc_sysctl.c | 2 +-
> kernel/ucount.c | 2 +-
> net/sysctl_net.c | 2 +-
> 4 files changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h
> index ee7d33b89e9e..0a55b5aade16 100644
> --- a/include/linux/sysctl.h
> +++ b/include/linux/sysctl.h
> @@ -207,7 +207,7 @@ struct ctl_table_root {
> void (*set_ownership)(struct ctl_table_header *head,
> struct ctl_table *table,
> kuid_t *uid, kgid_t *gid);
> - int (*permissions)(struct ctl_table_header *head, struct ctl_table *table);
> + int (*permissions)(struct ctl_table_header *head, const struct ctl_table *table);
> };
>
> #define register_sysctl(path, table) \
> diff --git a/ipc/ipc_sysctl.c b/ipc/ipc_sysctl.c
> index 8c62e443f78b..b087787f608f 100644
> --- a/ipc/ipc_sysctl.c
> +++ b/ipc/ipc_sysctl.c
> @@ -190,7 +190,7 @@ static int set_is_seen(struct ctl_table_set *set)
> return ¤t->nsproxy->ipc_ns->ipc_set == set;
> }
>
> -static int ipc_permissions(struct ctl_table_header *head, struct ctl_table *table)
> +static int ipc_permissions(struct ctl_table_header *head, const struct ctl_table *table)
> {
> int mode = table->mode;
>
> diff --git a/kernel/ucount.c b/kernel/ucount.c
> index 4aa6166cb856..90300840256b 100644
> --- a/kernel/ucount.c
> +++ b/kernel/ucount.c
> @@ -38,7 +38,7 @@ static int set_is_seen(struct ctl_table_set *set)
> }
>
> static int set_permissions(struct ctl_table_header *head,
> - struct ctl_table *table)
> + const struct ctl_table *table)
> {
> struct user_namespace *user_ns =
> container_of(head->set, struct user_namespace, set);
> diff --git a/net/sysctl_net.c b/net/sysctl_net.c
> index 051ed5f6fc93..ba9a49de9600 100644
> --- a/net/sysctl_net.c
> +++ b/net/sysctl_net.c
> @@ -40,7 +40,7 @@ static int is_seen(struct ctl_table_set *set)
>
> /* Return standard mode bits for table entry. */
> static int net_ctl_permissions(struct ctl_table_header *head,
> - struct ctl_table *table)
> + const struct ctl_table *table)
> {
> struct net *net = container_of(head->set, struct net, sysctls);
>
>
> ---
> base-commit: ffd2cb6b718e189e7e2d5d0c19c25611f92e061a
> change-id: 20231226-sysctl-const-permissions-d7cfd02a7637
>
> Best regards,
> --
> Thomas Wei?schuh <[email protected]>
>
--
Joel Granados
Hi!
On 2024-03-03 15:34:08+0100, Joel Granados wrote:
> Just to be sure I'm following. This is V2 of "[PATCH] sysctl: treewide:
> constify ctl_table_root::set_ownership". Right? I ask, because the
> subject changes slightly.
No, the v1 of this patch is linked in the patch log below.
The patches for ::set_ownership and ::permissions are changing two
different callbacks and both of them are needed.
The v2 for set_ownership is here:
https://lore.kernel.org/lkml/[email protected]/
Regards
>
> Best
>
> On Fri, Feb 23, 2024 at 04:52:16PM +0100, Thomas Weißschuh wrote:
> > The permissions callback is not supposed to modify the ctl_table.
> > Enforce this expectation via the typesystem.
> >
> > The patch was created with the following coccinelle script:
> >
> > @@
> > identifier func, head, ctl;
> > @@
> >
> > int func(
> > struct ctl_table_header *head,
> > - struct ctl_table *ctl)
> > + const struct ctl_table *ctl)
> > { ... }
> >
> > (insert_entry() from fs/proc/proc_sysctl.c is a false-positive)
> >
> > The three changed locations were validated through manually inspection
> > and compilation.
> >
> > In addition a search for '.permissions =' was done over the full tree to
> > look for places that were missed by coccinelle.
> > None were found.
> >
> > This change also is a step to put "struct ctl_table" into .rodata
> > throughout the kernel.
> >
> > Signed-off-by: Thomas Weißschuh <[email protected]>
> > ---
> > To: Luis Chamberlain <[email protected]>
> > To: Kees Cook <[email protected]>
> > To: Joel Granados <[email protected]>
> > To: David S. Miller <[email protected]>
> > Signed-off-by: Thomas Weißschuh <[email protected]>
> >
> > Changes in v2:
> > - flesh out commit messages
> > - Integrate changes to set_ownership and ctl_table_args into a single
> > series
> > - Link to v1: https://lore.kernel.org/r/20231226-sysctl-const-permissions-v1-1-5cd3c91f6299@weissschuh.net
> > ---
> > The patch is meant to be merged via the sysctl tree.
> >
> > There is an upcoming series that will introduce a new implementation of
> > .permission which would need to be adapted [0].
> > The adaption would be trivial as the 'table' parameter also not modified
> > there.
> >
> > This change was originally part of the sysctl-const series [1].
> > To slim down that series and reduce the message load on other
> > maintainers to a minimumble, submit this patch on its own.
> >
> > [0] https://lore.kernel.org/lkml/[email protected]/
> > [1] https://lore.kernel.org/lkml/[email protected]/
> > ---
> > include/linux/sysctl.h | 2 +-
> > ipc/ipc_sysctl.c | 2 +-
> > kernel/ucount.c | 2 +-
> > net/sysctl_net.c | 2 +-
> > 4 files changed, 4 insertions(+), 4 deletions(-)
> >
> > diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h
> > index ee7d33b89e9e..0a55b5aade16 100644
> > --- a/include/linux/sysctl.h
> > +++ b/include/linux/sysctl.h
> > @@ -207,7 +207,7 @@ struct ctl_table_root {
> > void (*set_ownership)(struct ctl_table_header *head,
> > struct ctl_table *table,
> > kuid_t *uid, kgid_t *gid);
> > - int (*permissions)(struct ctl_table_header *head, struct ctl_table *table);
> > + int (*permissions)(struct ctl_table_header *head, const struct ctl_table *table);
> > };
> >
> > #define register_sysctl(path, table) \
> > diff --git a/ipc/ipc_sysctl.c b/ipc/ipc_sysctl.c
> > index 8c62e443f78b..b087787f608f 100644
> > --- a/ipc/ipc_sysctl.c
> > +++ b/ipc/ipc_sysctl.c
> > @@ -190,7 +190,7 @@ static int set_is_seen(struct ctl_table_set *set)
> > return ¤t->nsproxy->ipc_ns->ipc_set == set;
> > }
> >
> > -static int ipc_permissions(struct ctl_table_header *head, struct ctl_table *table)
> > +static int ipc_permissions(struct ctl_table_header *head, const struct ctl_table *table)
> > {
> > int mode = table->mode;
> >
> > diff --git a/kernel/ucount.c b/kernel/ucount.c
> > index 4aa6166cb856..90300840256b 100644
> > --- a/kernel/ucount.c
> > +++ b/kernel/ucount.c
> > @@ -38,7 +38,7 @@ static int set_is_seen(struct ctl_table_set *set)
> > }
> >
> > static int set_permissions(struct ctl_table_header *head,
> > - struct ctl_table *table)
> > + const struct ctl_table *table)
> > {
> > struct user_namespace *user_ns =
> > container_of(head->set, struct user_namespace, set);
> > diff --git a/net/sysctl_net.c b/net/sysctl_net.c
> > index 051ed5f6fc93..ba9a49de9600 100644
> > --- a/net/sysctl_net.c
> > +++ b/net/sysctl_net.c
> > @@ -40,7 +40,7 @@ static int is_seen(struct ctl_table_set *set)
> >
> > /* Return standard mode bits for table entry. */
> > static int net_ctl_permissions(struct ctl_table_header *head,
> > - struct ctl_table *table)
> > + const struct ctl_table *table)
> > {
> > struct net *net = container_of(head->set, struct net, sysctls);
> >
> >
> > ---
> > base-commit: ffd2cb6b718e189e7e2d5d0c19c25611f92e061a
> > change-id: 20231226-sysctl-const-permissions-d7cfd02a7637
> >
> > Best regards,
> > --
> > Thomas Weißschuh <[email protected]>
> >
>
> --
>
> Joel Granados
On Sun, Mar 10, 2024 at 10:18:07AM +0100, Thomas Wei?schuh wrote:
> Hi!
>
> On 2024-03-03 15:34:08+0100, Joel Granados wrote:
> > Just to be sure I'm following. This is V2 of "[PATCH] sysctl: treewide:
> > constify ctl_table_root::set_ownership". Right? I ask, because the
> > subject changes slightly.
>
> No, the v1 of this patch is linked in the patch log below.
>
> The patches for ::set_ownership and ::permissions are changing two
> different callbacks and both of them are needed.
Awesome. thx for clarifying. So the ::permissions one I have reviewed
and have added to the constification branch in sysctl repo for testing.
I'm missing the review for the set_ownership one.
Best
>
> The v2 for set_ownership is here:
> https://lore.kernel.org/lkml/[email protected]/
>
> Regards
>
> >
> > Best
> >
> > On Fri, Feb 23, 2024 at 04:52:16PM +0100, Thomas Wei?schuh wrote:
> > > The permissions callback is not supposed to modify the ctl_table.
> > > Enforce this expectation via the typesystem.
> > >
> > > The patch was created with the following coccinelle script:
> > >
> > > @@
> > > identifier func, head, ctl;
> > > @@
> > >
> > > int func(
> > > struct ctl_table_header *head,
> > > - struct ctl_table *ctl)
> > > + const struct ctl_table *ctl)
> > > { ... }
> > >
> > > (insert_entry() from fs/proc/proc_sysctl.c is a false-positive)
> > >
> > > The three changed locations were validated through manually inspection
> > > and compilation.
> > >
> > > In addition a search for '.permissions =' was done over the full tree to
> > > look for places that were missed by coccinelle.
> > > None were found.
> > >
> > > This change also is a step to put "struct ctl_table" into .rodata
> > > throughout the kernel.
> > >
> > > Signed-off-by: Thomas Wei?schuh <[email protected]>
> > > ---
> > > To: Luis Chamberlain <[email protected]>
> > > To: Kees Cook <[email protected]>
> > > To: Joel Granados <[email protected]>
> > > To: David S. Miller <[email protected]>
> > > Signed-off-by: Thomas Wei?schuh <[email protected]>
> > >
> > > Changes in v2:
> > > - flesh out commit messages
> > > - Integrate changes to set_ownership and ctl_table_args into a single
> > > series
> > > - Link to v1: https://lore.kernel.org/r/20231226-sysctl-const-permissions-v1-1-5cd3c91f6299@weissschuh.net
> > > ---
> > > The patch is meant to be merged via the sysctl tree.
> > >
> > > There is an upcoming series that will introduce a new implementation of
> > > .permission which would need to be adapted [0].
> > > The adaption would be trivial as the 'table' parameter also not modified
> > > there.
> > >
> > > This change was originally part of the sysctl-const series [1].
> > > To slim down that series and reduce the message load on other
> > > maintainers to a minimumble, submit this patch on its own.
> > >
> > > [0] https://lore.kernel.org/lkml/[email protected]/
> > > [1] https://lore.kernel.org/lkml/[email protected]/
> > > ---
> > > include/linux/sysctl.h | 2 +-
> > > ipc/ipc_sysctl.c | 2 +-
> > > kernel/ucount.c | 2 +-
> > > net/sysctl_net.c | 2 +-
> > > 4 files changed, 4 insertions(+), 4 deletions(-)
> > >
> > > diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h
> > > index ee7d33b89e9e..0a55b5aade16 100644
> > > --- a/include/linux/sysctl.h
> > > +++ b/include/linux/sysctl.h
> > > @@ -207,7 +207,7 @@ struct ctl_table_root {
> > > void (*set_ownership)(struct ctl_table_header *head,
> > > struct ctl_table *table,
> > > kuid_t *uid, kgid_t *gid);
> > > - int (*permissions)(struct ctl_table_header *head, struct ctl_table *table);
> > > + int (*permissions)(struct ctl_table_header *head, const struct ctl_table *table);
> > > };
> > >
> > > #define register_sysctl(path, table) \
> > > diff --git a/ipc/ipc_sysctl.c b/ipc/ipc_sysctl.c
> > > index 8c62e443f78b..b087787f608f 100644
> > > --- a/ipc/ipc_sysctl.c
> > > +++ b/ipc/ipc_sysctl.c
> > > @@ -190,7 +190,7 @@ static int set_is_seen(struct ctl_table_set *set)
> > > return ¤t->nsproxy->ipc_ns->ipc_set == set;
> > > }
> > >
> > > -static int ipc_permissions(struct ctl_table_header *head, struct ctl_table *table)
> > > +static int ipc_permissions(struct ctl_table_header *head, const struct ctl_table *table)
> > > {
> > > int mode = table->mode;
> > >
> > > diff --git a/kernel/ucount.c b/kernel/ucount.c
> > > index 4aa6166cb856..90300840256b 100644
> > > --- a/kernel/ucount.c
> > > +++ b/kernel/ucount.c
> > > @@ -38,7 +38,7 @@ static int set_is_seen(struct ctl_table_set *set)
> > > }
> > >
> > > static int set_permissions(struct ctl_table_header *head,
> > > - struct ctl_table *table)
> > > + const struct ctl_table *table)
> > > {
> > > struct user_namespace *user_ns =
> > > container_of(head->set, struct user_namespace, set);
> > > diff --git a/net/sysctl_net.c b/net/sysctl_net.c
> > > index 051ed5f6fc93..ba9a49de9600 100644
> > > --- a/net/sysctl_net.c
> > > +++ b/net/sysctl_net.c
> > > @@ -40,7 +40,7 @@ static int is_seen(struct ctl_table_set *set)
> > >
> > > /* Return standard mode bits for table entry. */
> > > static int net_ctl_permissions(struct ctl_table_header *head,
> > > - struct ctl_table *table)
> > > + const struct ctl_table *table)
> > > {
> > > struct net *net = container_of(head->set, struct net, sysctls);
> > >
> > >
> > > ---
> > > base-commit: ffd2cb6b718e189e7e2d5d0c19c25611f92e061a
> > > change-id: 20231226-sysctl-const-permissions-d7cfd02a7637
> > >
> > > Best regards,
> > > --
> > > Thomas Wei?schuh <[email protected]>
> > >
> >
> > --
> >
> > Joel Granados
>
>
--
Joel Granados