10/18/2023 3:29 PM, Mickaël Salaün пишет:
> On Mon, Oct 16, 2023 at 09:50:26AM +0800, Konstantin Meskhidze wrote:
> > This commit adds network rules support in the ruleset management
>
> Here are some advices to better write commit messages:
> https://docs.kernel.org/process/submitting-patches.html#describe-your-changes
> The "Describe your changes in imperative mood" part is important for
> this commit and others. Most of this patch series' commit messages need
> small updates.
Ok. I will refactor commit messages with "imperative mood". Thanks.
>
> > helpers and the landlock_create_ruleset syscall.
> > Refactor user space API to support network actions. Add new network
> > access flags, network rule and network attributes. Increment Landlock
> > ABI version. Expand access_masks_t to u32 to be sure network access
>
> Please explain the "why" (when it makes sense) instead of just listing
> the "what".
Ok.
>
> > rights can be stored. Implement socket_bind() and socket_connect()
> > LSM hooks, which enables to restrict TCP socket binding and connection
> > to specific ports.
>
> I reworded and moved this part in last:
> > For the file system, a file descriptor is a direct access to a file/data.
> > But for the network, it's impossible to identify for which data/peer a
> > newly created socket will give access to, it's needed to wait for a
> > connect or bind request to identify the use case for this socket.
> > That's why the access rights (related to ports) are tied to an opened
> > socket, but this would not align with the way Landlock access control
> > works for the filesystem [2].
Thanks.
>
> Please add empty line to split paragraphs.
Got it.
>
> > The new landlock_net_port_attr structure has two fields. The allowed_access
> > field contains the LANDLOCK_ACCESS_NET_* rights. The port field contains
> > the port value according to the allowed protocol. This field can
> > take up to a 64-bit value [1] but the maximum value depends on the related
> > protocol (e.g. 16-bit for TCP).
>
> For the file system, a file descriptor is a direct access to a file/data.
> However, for network sockets, we cannot identify for which data or peer a newly
> created socket will give access to. Indeed, we need to wait for a connect or
> bind request to identify the use case for this socket.
>
> Access rights are not tied to socket file descriptors. Instead, bind and
> connect actions are controlled by the task's domain. As for the filesystem, a
> directory file descriptor may enable to open another file (i.e. a new data
> item), but this opening is restricted by the task's domain, not the file
> descriptor's access rights [2].
>
> >
> > [1]
> > https://lore.kernel.org/r/278ab07f-7583-a4e0-3d37-1bacd091531d@xxxxxxxxxxx
> > [2]
> > https://lore.kernel.org/all/263c1eb3-602f-57fe-8450-3f138581bee7@xxxxxxxxxxx
>
> [1] https://lore.kernel.org/r/278ab07f-7583-a4e0-3d37-1bacd091531d@xxxxxxxxxxx
> [2] https://lore.kernel.org/r/263c1eb3-602f-57fe-8450-3f138581bee7@xxxxxxxxxxx
Thanks.
>
> >
> > Signed-off-by: Konstantin Meskhidze <konstantin.meskhidze@xxxxxxxxxx>
> > Link: https://lore.kernel.org/r/20230920092641.832134-9-konstantin.meskhidze@xxxxxxxxxx
> > [mic: Remove !ARCH_EPHEMERAL_INODES in Kconfig, and add landlock_ prefix
> > to add_rule_net_service()]
> > Signed-off-by: Mickaël Salaün <mic@xxxxxxxxxxx>
> > ---
> >
> > Changes since v12:
> > * Moves add_rule_net_port() back in syscalls.c and makes it static.
> > * Deletes bind_access_mask allowing bind action rule on port 0.
> > * Adds comment about port 0 in landlock_net_port_attr structure.
> > * Removes !ARCH_EPHEMERAL_INODES from Kconfig.
> > * Minor fixes.
> > * Refactors commit message.
> >
> > Changes since v11:
> > * Replaces dates with "2022-2023" in net.c/h files headers.
> > * Removes WARN_ON_ONCE(!domain) in check_socket_access().
> > * Using "typeof(*address)" instead of offsetofend(struct sockaddr, sa_family).
> > * Renames LANDLOCK_RULE_NET_SERVICE to LANDLOCK_RULE_NET_PORT.
> > * Renames landlock_net_service_attr to landlock_net_port_attr.
> > * Defines two add_rule_net_service() functions according to
> > IS_ENABLED(CONFIG_INET) instead of changing the body of the only
> > function.
> > * Adds af_family consistency check while handling AF_UNSPEC specifically.
> > * Adds bind_access_mask in add_rule_net_service() to deny all rules with bind
> > action on port zero.
> > * Minor fixes.
> > * Refactors commit message.
> >
> > Changes since v10:
> > * Removes "packed" attribute.
> > * Applies Mickaёl's patch with some refactoring.
> > * Deletes get_port() and check_addrlen() helpers.
> > * Refactors check_socket_access() by squashing get_port() and
> > check_addrlen() helpers into it.
> > * Fixes commit message.
> >
> > Changes since v9:
> > * Changes UAPI port field to __u64.
> > * Moves shared code into check_socket_access().
> > * Adds get_raw_handled_net_accesses() and
> > get_current_net_domain() helpers.
> > * Minor fixes.
> >
> > Changes since v8:
> > * Squashes commits.
> > * Refactors commit message.
> > * Changes UAPI port field to __be16.
> > * Changes logic of bind/connect hooks with AF_UNSPEC families.
> > * Adds address length checking.
> > * Minor fixes.
> >
> > Changes since v7:
> > * Squashes commits.
> > * Increments ABI version to 4.
> > * Refactors commit message.
> > * Minor fixes.
> >
> > Changes since v6:
> > * Renames landlock_set_net_access_mask() to landlock_add_net_access_mask()
> > because it OR values.
> > * Makes landlock_add_net_access_mask() more resilient incorrect values.
> > * Refactors landlock_get_net_access_mask().
> > * Renames LANDLOCK_MASK_SHIFT_NET to LANDLOCK_SHIFT_ACCESS_NET and use
> > LANDLOCK_NUM_ACCESS_FS as value.
> > * Updates access_masks_t to u32 to support network access actions.
> > * Refactors landlock internal functions to support network actions with
> > landlock_key/key_type/id types.
> >
> > Changes since v5:
> > * Gets rid of partial revert from landlock_add_rule
> > syscall.
> > * Formats code with clang-format-14.
> >
> > Changes since v4:
> > * Refactors landlock_create_ruleset() - splits ruleset and
> > masks checks.
> > * Refactors landlock_create_ruleset() and landlock mask
> > setters/getters to support two rule types.
> > * Refactors landlock_add_rule syscall add_rule_path_beneath
> > function by factoring out get_ruleset_from_fd() and
> > landlock_put_ruleset().
> >
> > Changes since v3:
> > * Splits commit.
> > * Adds network rule support for internal landlock functions.
> > * Adds set_mask and get_mask for network.
> > * Adds rb_root root_net_port.
> >
> > ---
> > include/uapi/linux/landlock.h | 56 ++++++
> > security/landlock/Kconfig | 1 +
> > security/landlock/Makefile | 2 +
> > security/landlock/limits.h | 5 +
> > security/landlock/net.c | 198 +++++++++++++++++++
> > security/landlock/net.h | 33 ++++
> > security/landlock/ruleset.c | 62 +++++-
> > security/landlock/ruleset.h | 59 +++++-
> > security/landlock/setup.c | 2 +
> > security/landlock/syscalls.c | 69 ++++++-
> > tools/testing/selftests/landlock/base_test.c | 2 +-
> > 11 files changed, 466 insertions(+), 23 deletions(-)
> > create mode 100644 security/landlock/net.c
> > create mode 100644 security/landlock/net.h
> >
> > diff --git a/include/uapi/linux/landlock.h b/include/uapi/linux/landlock.h
> > index 81d09ef9aa50..25349666b19e 100644
> > --- a/include/uapi/linux/landlock.h
> > +++ b/include/uapi/linux/landlock.h
> > @@ -31,6 +31,12 @@ struct landlock_ruleset_attr {
> > * this access right.
> > */
> > __u64 handled_access_fs;
> > + /**
> > + * @handled_access_net: Bitmask of actions (cf. `Network flags`_)
> > + * that is handled by this ruleset and should then be forbidden if no
> > + * rule explicitly allow them.
> > + */
> > + __u64 handled_access_net;
> > };
> >
> > /*
> > @@ -54,6 +60,11 @@ enum landlock_rule_type {
> > * landlock_path_beneath_attr .
> > */
> > LANDLOCK_RULE_PATH_BENEATH = 1,
> > + /**
> > + * @LANDLOCK_RULE_NET_PORT: Type of a &struct
> > + * landlock_net_port_attr .
> > + */
> > + LANDLOCK_RULE_NET_PORT = 2,
>
> We don't need the explicit " = 2".
Fixed. Thanks.
>
> > };
> >
> > /**
> > @@ -79,6 +90,32 @@ struct landlock_path_beneath_attr {
> > */
> > } __attribute__((packed));
> >
> > +/**
> > + * struct landlock_net_port_attr - Network port definition
> > + *
> > + * Argument of sys_landlock_add_rule().
> > + */
> > +struct landlock_net_port_attr {
> > + /**
> > + * @allowed_access: Bitmask of allowed access network for a port
> > + * (cf. `Network flags`_).
> > + */
> > + __u64 allowed_access;
> > + /**
> > + * @port: Network port. Landlock does not forbid rules with port 0,
> > + * since some network services use it. Port 0 is a reserved one in
> > + * TCP/IP networking, meaning that it should not be used in TCP or
> > + * UDP messages. To allocate its source port number, services call
> > + * TCP/IP network functions like bind() to request one. With port 0
> > + * it triggers the operating system to automatically search for
> > + * and return a suitable available port in the TCP/IP dynamic
> > + * port number range. This port range can be controlled by a
> > + * sysadmin with /proc/sys/net/ipv4/ip_local_port_range sysctl,
> > + * which is also used by IPv6.
>
> This looks too inspired from
> https://www.lifewire.com/port-0-in-tcp-and-udp-818145
Yep. You are right.
>
> Let's make it simpler:
>
> * @port: Network port.
> *
> * It should be noted that port 0 passed to :manpage:`bind(2)` will
> * bind to an available port from a specific port range. This can be
> * configured thanks to the ``/proc/sys/net/ipv4/ip_local_port_range``
> * sysctl (also used for IPv6). A Landlock rule with port 0 and the
> * ``LANDLOCK_ACCESS_NET_BIND_TCP`` right means that requesting to bind
> * on port 0 is allowed and it will automatically translate to binding
> * on the related port range.
Thanks.
>
> > + */
> > + __u64 port;
> > +};
> > +
> > /**
> > * DOC: fs_access
> > *
> > @@ -189,4 +226,23 @@ struct landlock_path_beneath_attr {
> > #define LANDLOCK_ACCESS_FS_TRUNCATE (1ULL << 14)
> > /* clang-format on */
> >
> > +/**
> > + * DOC: net_access
> > + *
> > + * Network flags
> > + * ~~~~~~~~~~~~~~~~
> > + *
> > + * These flags enable to restrict a sandboxed process to a set of network
> > + * actions.
>
> You can add:
> "This is supported since ABI 4."
Updated.
>
> > + *
> > + * TCP sockets with allowed actions:
> > + *
> > + * - %LANDLOCK_ACCESS_NET_BIND_TCP: Bind a TCP socket to a local port.
> > + * - %LANDLOCK_ACCESS_NET_CONNECT_TCP: Connect an active TCP socket to
> > + * a remote port.
> > + */
> > +/* clang-format off */
> > +#define LANDLOCK_ACCESS_NET_BIND_TCP (1ULL << 0)
> > +#define LANDLOCK_ACCESS_NET_CONNECT_TCP (1ULL << 1)
> > +/* clang-format on */
> > #endif /* _UAPI_LINUX_LANDLOCK_H */
> > diff --git a/security/landlock/Kconfig b/security/landlock/Kconfig
> > index c1e862a38410..c4bf0d5eff39 100644
> > --- a/security/landlock/Kconfig
> > +++ b/security/landlock/Kconfig
> > @@ -3,6 +3,7 @@
> > config SECURITY_LANDLOCK
> > bool "Landlock support"
> > depends on SECURITY
> > + select SECURITY_NETWORK
> > select SECURITY_PATH
> > help
> > Landlock is a sandboxing mechanism that enables processes to restrict
> > diff --git a/security/landlock/Makefile b/security/landlock/Makefile
> > index 7bbd2f413b3e..53d3c92ae22e 100644
> > --- a/security/landlock/Makefile
> > +++ b/security/landlock/Makefile
> > @@ -2,3 +2,5 @@ obj-$(CONFIG_SECURITY_LANDLOCK) := landlock.o
> >
> > landlock-y := setup.o syscalls.o object.o ruleset.o \
> > cred.o ptrace.o fs.o
> > +
> > +landlock-$(CONFIG_INET) += net.o
> > \ No newline at end of file
> > diff --git a/security/landlock/limits.h b/security/landlock/limits.h
> > index bafb3b8dc677..93c9c6f91556 100644
> > --- a/security/landlock/limits.h
> > +++ b/security/landlock/limits.h
> > @@ -23,6 +23,11 @@
> > #define LANDLOCK_NUM_ACCESS_FS __const_hweight64(LANDLOCK_MASK_ACCESS_FS)
> > #define LANDLOCK_SHIFT_ACCESS_FS 0
> >
> > +#define LANDLOCK_LAST_ACCESS_NET LANDLOCK_ACCESS_NET_CONNECT_TCP
> > +#define LANDLOCK_MASK_ACCESS_NET ((LANDLOCK_LAST_ACCESS_NET << 1) - 1)
> > +#define LANDLOCK_NUM_ACCESS_NET __const_hweight64(LANDLOCK_MASK_ACCESS_NET)
> > +#define LANDLOCK_SHIFT_ACCESS_NET LANDLOCK_NUM_ACCESS_FS
> > +
> > /* clang-format on */
> >
> > #endif /* _SECURITY_LANDLOCK_LIMITS_H */
> > diff --git a/security/landlock/net.c b/security/landlock/net.c
> > new file mode 100644
> > index 000000000000..1bf26cf3c41b
> > --- /dev/null
> > +++ b/security/landlock/net.c
> > @@ -0,0 +1,198 @@
> > +// SPDX-License-Identifier: GPL-2.0-only
> > +/*
> > + * Landlock LSM - Network management and hooks
> > + *
> > + * Copyright © 2022-2023 Huawei Tech. Co., Ltd.
> > + * Copyright © 2022-2023 Microsoft Corporation
> > + */
> > +
> > +#include <linux/in.h>
> > +#include <linux/net.h>
> > +#include <linux/socket.h>
> > +#include <net/ipv6.h>
> > +
> > +#include "common.h"
> > +#include "cred.h"
> > +#include "limits.h"
> > +#include "net.h"
> > +#include "ruleset.h"
> > +
> > +int landlock_append_net_rule(struct landlock_ruleset *const ruleset,
> > + const u16 port, access_mask_t access_rights)
> > +{
> > + int err;
> > + const struct landlock_id id = {
> > + .key.data = (__force uintptr_t)htons(port),
> > + .type = LANDLOCK_KEY_NET_PORT,
> > + };
> > +
> > + BUILD_BUG_ON(sizeof(port) > sizeof(id.key.data));
> > +
> > + /* Transforms relative access rights to absolute ones. */
> > + access_rights |= LANDLOCK_MASK_ACCESS_NET &
> > + ~landlock_get_net_access_mask(ruleset, 0);
> > +
> > + mutex_lock(&ruleset->lock);
> > + err = landlock_insert_rule(ruleset, id, access_rights);
> > + mutex_unlock(&ruleset->lock);
> > +
> > + return err;
> > +}
> > +
> > +static access_mask_t
> > +get_raw_handled_net_accesses(const struct landlock_ruleset *const domain)
> > +{
> > + access_mask_t access_dom = 0;
> > + size_t layer_level;
> > +
> > + for (layer_level = 0; layer_level < domain->num_layers; layer_level++)
> > + access_dom |= landlock_get_net_access_mask(domain, layer_level);
> > + return access_dom;
> > +}
> > +
> > +static const struct landlock_ruleset *get_current_net_domain(void)
> > +{
> > + const struct landlock_ruleset *const dom =
> > + landlock_get_current_domain();
> > +
> > + if (!dom || !get_raw_handled_net_accesses(dom))
> > + return NULL;
> > +
> > + return dom;
> > +}
> > +
> > +static int check_socket_access(struct socket *const sock,
>
> To be consistent with current_check_access_path(), please rename to
> current_check_access_socket().
Done. Thanks.
>
> > + struct sockaddr *const address,
> > + const int addrlen,
> > + const access_mask_t access_request)
> > +{
> > + __be16 port;
> > + layer_mask_t layer_masks[LANDLOCK_NUM_ACCESS_NET] = {};
> > + const struct landlock_rule *rule;
> > + access_mask_t handled_access;
> > + struct landlock_id id = {
> > + .type = LANDLOCK_KEY_NET_PORT,
> > + };
> > + const struct landlock_ruleset *const domain = get_current_net_domain();
>
> For consistency with other functions, s/domain/dom/g
Ok. Fixed.
>
> > +
> > + if (!domain)
> > + return 0;
> > + if (WARN_ON_ONCE(domain->num_layers < 1))
> > + return -EACCES;
> > +
> > + /* Checks if it's a (potential) TCP socket. */
> > + if (sock->type != SOCK_STREAM)
> > + return 0;
> > +
> > + /* Checks for minimal header length to safely read sa_family. */
> > + if (addrlen < offsetofend(typeof(*address), sa_family))
> > + return -EINVAL;
> > +
> > + switch (address->sa_family) {
> > + case AF_UNSPEC:
> > + case AF_INET:
> > + if (addrlen < sizeof(struct sockaddr_in))
> > + return -EINVAL;
> > + port = ((struct sockaddr_in *)address)->sin_port;
> > + break;
> > +#if IS_ENABLED(CONFIG_IPV6)
> > + case AF_INET6:
> > + if (addrlen < SIN6_LEN_RFC2133)
> > + return -EINVAL;
> > + port = ((struct sockaddr_in6 *)address)->sin6_port;
> > + break;
> > +#endif
>
> #endif /* IS_ENABLED(CONFIG_INET) */
#endif /* IS_ENABLED(CONFIG_IPV6) */ I suppose.
>
> > + default:
> > + return 0;
> > + }
> > +
> > + /* Specific AF_UNSPEC handling. */
> > + if (address->sa_family == AF_UNSPEC) {
> > + /*
> > + * Connecting to an address with AF_UNSPEC dissolves the TCP
> > + * association, which have the same effect as closing the
> > + * connection while retaining the socket object (i.e., the file
> > + * descriptor). As for dropping privileges, closing
> > + * connections is always allowed.
> > + *
> > + * For a TCP access control system, this request is legitimate.
> > + * Let the network stack handle potential inconsistencies and
> > + * return -EINVAL if needed.
> > + */
> > + if (access_request == LANDLOCK_ACCESS_NET_CONNECT_TCP)
> > + return 0;
> > +
> > + /*
> > + * For compatibility reason, accept AF_UNSPEC for bind
> > + * accesses (mapped to AF_INET) only if the address is
> > + * INADDR_ANY (cf. __inet_bind). Checking the address is
> > + * required to not wrongfully return -EACCES instead of
> > + * -EAFNOSUPPORT.
> > + *
> > + * We could return 0 and let the network stack handle these
> > + * checks, but it is safer to return a proper error and test
> > + * consistency thanks to kselftest.
> > + */
> > + if (access_request == LANDLOCK_ACCESS_NET_BIND_TCP) {
> > + /* addrlen has already been checked for AF_UNSPEC. */
> > + const struct sockaddr_in *const sockaddr =
> > + (struct sockaddr_in *)address;
> > +
> > + if (sock->sk->__sk_common.skc_family != AF_INET)
> > + return -EINVAL;
> > +
> > + if (sockaddr->sin_addr.s_addr != htonl(INADDR_ANY))
> > + return -EAFNOSUPPORT;
> > + }
> > + } else {
> > + /*
> > + * Checks sa_family consistency to not wrongfully return
> > + * -EACCES instead of -EINVAL. Valid sa_family changes are
> > + * only (from AF_INET or AF_INET6) to AF_UNSPEC.
> > + *
> > + * We could return 0 and let the network stack handle this
> > + * check, but it is safer to return a proper error and test
> > + * consistency thanks to kselftest.
> > + */
> > + if (address->sa_family != sock->sk->__sk_common.skc_family)
> > + return -EINVAL;
> > + }
> > +
> > + id.key.data = (__force uintptr_t)port;
> > + BUILD_BUG_ON(sizeof(port) > sizeof(id.key.data));
> > +
> > + rule = landlock_find_rule(domain, id);
> > + handled_access = landlock_init_layer_masks(
> > + domain, access_request, &layer_masks, LANDLOCK_KEY_NET_PORT);
> > + if (landlock_unmask_layers(rule, handled_access, &layer_masks,
> > + ARRAY_SIZE(layer_masks)))
> > + return 0;
> > +
> > + return -EACCES;
> > +}
> > +
> > +static int hook_socket_bind(struct socket *const sock,
> > + struct sockaddr *const address, const int addrlen)
> > +{
> > + return check_socket_access(sock, address, addrlen,
> > + LANDLOCK_ACCESS_NET_BIND_TCP);
> > +}
> > +
> > +static int hook_socket_connect(struct socket *const sock,
> > + struct sockaddr *const address,
> > + const int addrlen)
> > +{
> > + return check_socket_access(sock, address, addrlen,
> > + LANDLOCK_ACCESS_NET_CONNECT_TCP);
> > +}
> > +
> > +static struct security_hook_list landlock_hooks[] __ro_after_init = {
> > + LSM_HOOK_INIT(socket_bind, hook_socket_bind),
> > + LSM_HOOK_INIT(socket_connect, hook_socket_connect),
> > +};
> > +
> > +__init void landlock_add_net_hooks(void)
> > +{
> > + security_add_hooks(landlock_hooks, ARRAY_SIZE(landlock_hooks),
> > + LANDLOCK_NAME);
> > +}
> > diff --git a/security/landlock/net.h b/security/landlock/net.h
> > new file mode 100644
> > index 000000000000..588a49fd6907
> > --- /dev/null
> > +++ b/security/landlock/net.h
> > @@ -0,0 +1,33 @@
> > +/* SPDX-License-Identifier: GPL-2.0-only */
> > +/*
> > + * Landlock LSM - Network management and hooks
> > + *
> > + * Copyright © 2022-2023 Huawei Tech. Co., Ltd.
> > + */
> > +
> > +#ifndef _SECURITY_LANDLOCK_NET_H
> > +#define _SECURITY_LANDLOCK_NET_H
> > +
> > +#include "common.h"
> > +#include "ruleset.h"
> > +#include "setup.h"
> > +
> > +#if IS_ENABLED(CONFIG_INET)
> > +__init void landlock_add_net_hooks(void);
> > +
> > +int landlock_append_net_rule(struct landlock_ruleset *const ruleset,
> > + const u16 port, access_mask_t access_rights);
> > +#else /* IS_ENABLED(CONFIG_INET) */
> > +static inline void landlock_add_net_hooks(void)
> > +{
> > +}
> > +
> > +static inline int
> > +landlock_append_net_rule(struct landlock_ruleset *const ruleset, const u16 port,
> > + access_mask_t access_rights);
> > +{
> > + return -EAFNOSUPPORT;
> > +}
> > +#endif /* IS_ENABLED(CONFIG_INET) */
> > +
> > +#endif /* _SECURITY_LANDLOCK_NET_H */
> > diff --git a/security/landlock/ruleset.c b/security/landlock/ruleset.c
> > index 4c209acee01e..1fe4298ff4a7 100644
> > --- a/security/landlock/ruleset.c
> > +++ b/security/landlock/ruleset.c
> > @@ -36,6 +36,11 @@ static struct landlock_ruleset *create_ruleset(const u32 num_layers)
> > refcount_set(&new_ruleset->usage, 1);
> > mutex_init(&new_ruleset->lock);
> > new_ruleset->root_inode = RB_ROOT;
> > +
> > +#if IS_ENABLED(CONFIG_INET)
> > + new_ruleset->root_net_port = RB_ROOT;
> > +#endif /* IS_ENABLED(CONFIG_INET) */
> > +
> > new_ruleset->num_layers = num_layers;
> > /*
> > * hierarchy = NULL
> > @@ -46,16 +51,21 @@ static struct landlock_ruleset *create_ruleset(const u32 num_layers)
> > }
> >
> > struct landlock_ruleset *
> > -landlock_create_ruleset(const access_mask_t fs_access_mask)
> > +landlock_create_ruleset(const access_mask_t fs_access_mask,
> > + const access_mask_t net_access_mask)
> > {
> > struct landlock_ruleset *new_ruleset;
> >
> > /* Informs about useless ruleset. */
> > - if (!fs_access_mask)
> > + if (!fs_access_mask && !net_access_mask)
> > return ERR_PTR(-ENOMSG);
> > new_ruleset = create_ruleset(1);
> > - if (!IS_ERR(new_ruleset))
> > + if (IS_ERR(new_ruleset))
> > + return new_ruleset;
> > + if (fs_access_mask)
> > landlock_add_fs_access_mask(new_ruleset, fs_access_mask, 0);
> > + if (net_access_mask)
> > + landlock_add_net_access_mask(new_ruleset, net_access_mask, 0);
>
> This is good, but it is not tested: we need to add a test that both
> handle FS and net restrictions. You can add one in net.c, just handling
> LANDLOCK_ACCESS_FS_READ_DIR and LANDLOCK_ACCESS_NET_BIND_TCP, add one
> rule with path_beneath (e.g. /dev) and another with net_port, and check
> that open("/") is denied, open("/dev") is allowed, and and only the
> allowed port is allowed with bind(). This test should be simple and can
> only check against an IPv4 socket, i.e. using ipv4_tcp fixture, just
> after port_endianness. fcntl.h should then be included by net.c
Ok.
>
> I guess that was the purpose of layout1.with_net (in fs_test.c) but it
Yep. I added this kind of nest in fs_test.c to test both fs and network
rules together.
> is not complete. You can revamp this test and move it to net.c
> following the above suggestions, keeping it consistent with other tests
> in net.c . You don't need the test_open() nor create_ruleset() helpers.
>
> This test must failed if we change "ruleset->access_masks[layer_level] |="
> to "ruleset->access_masks[layer_level] =" in
> landlock_add_fs_access_mask() or landlock_add_net_access_mask().
Do you want to change it? Why?
