diff options
| -rw-r--r-- | Documentation/userspace-api/landlock.rst | 2 | ||||
| -rw-r--r-- | include/uapi/linux/landlock.h | 27 | ||||
| -rw-r--r-- | security/landlock/syscalls.c | 17 |
3 files changed, 24 insertions, 22 deletions
diff --git a/Documentation/userspace-api/landlock.rst b/Documentation/userspace-api/landlock.rst index 07b63aec56fa..37dafce8038b 100644 --- a/Documentation/userspace-api/landlock.rst +++ b/Documentation/userspace-api/landlock.rst @@ -8,7 +8,7 @@ Landlock: unprivileged access control ===================================== :Author: Mickaël Salaün -:Date: April 2024 +:Date: July 2024 The goal of Landlock is to enable to restrict ambient rights (e.g. global filesystem or network access) for a set of processes. Because Landlock diff --git a/include/uapi/linux/landlock.h b/include/uapi/linux/landlock.h index e76186da3260..2c8dbc74b955 100644 --- a/include/uapi/linux/landlock.h +++ b/include/uapi/linux/landlock.h @@ -104,20 +104,21 @@ struct landlock_path_beneath_attr { */ struct landlock_net_port_attr { /** - * @allowed_access: Bitmask of allowed access network for a port + * @allowed_access: Bitmask of allowed network actions for a port * (cf. `Network flags`_). */ __u64 allowed_access; /** * @port: Network port in host endianness. * - * 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. + * It should be noted that port 0 passed to :manpage:`bind(2)` will bind + * to an available port from the ephemeral port range. This can be + * configured with 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. */ __u64 port; }; @@ -138,10 +139,10 @@ struct landlock_net_port_attr { * The following access rights apply only to files: * * - %LANDLOCK_ACCESS_FS_EXECUTE: Execute a file. - * - %LANDLOCK_ACCESS_FS_WRITE_FILE: Open a file with write access. Note that - * you might additionally need the %LANDLOCK_ACCESS_FS_TRUNCATE right in order - * to overwrite files with :manpage:`open(2)` using ``O_TRUNC`` or - * :manpage:`creat(2)`. + * - %LANDLOCK_ACCESS_FS_WRITE_FILE: Open a file with write access. When + * opening files for writing, you will often additionally need the + * %LANDLOCK_ACCESS_FS_TRUNCATE right. In many cases, these system calls + * truncate existing files when overwriting them (e.g., :manpage:`creat(2)`). * - %LANDLOCK_ACCESS_FS_READ_FILE: Open a file with read access. * - %LANDLOCK_ACCESS_FS_TRUNCATE: Truncate a file with :manpage:`truncate(2)`, * :manpage:`ftruncate(2)`, :manpage:`creat(2)`, or :manpage:`open(2)` with @@ -263,7 +264,7 @@ struct landlock_net_port_attr { * These flags enable to restrict a sandboxed process to a set of network * actions. This is supported since the Landlock ABI version 4. * - * TCP sockets with allowed actions: + * The following access rights apply to TCP port numbers: * * - %LANDLOCK_ACCESS_NET_BIND_TCP: Bind a TCP socket to a local port. * - %LANDLOCK_ACCESS_NET_CONNECT_TCP: Connect an active TCP socket to diff --git a/security/landlock/syscalls.c b/security/landlock/syscalls.c index 03b470f5a85a..ccc8bc6c1584 100644 --- a/security/landlock/syscalls.c +++ b/security/landlock/syscalls.c @@ -378,8 +378,7 @@ static int add_rule_net_port(struct landlock_ruleset *ruleset, * with the new rule. * @rule_type: Identify the structure type pointed to by @rule_attr: * %LANDLOCK_RULE_PATH_BENEATH or %LANDLOCK_RULE_NET_PORT. - * @rule_attr: Pointer to a rule (only of type &struct - * landlock_path_beneath_attr for now). + * @rule_attr: Pointer to a rule (matching the @rule_type). * @flags: Must be 0. * * This system call enables to define a new rule and add it to an existing @@ -390,18 +389,20 @@ static int add_rule_net_port(struct landlock_ruleset *ruleset, * - %EOPNOTSUPP: Landlock is supported by the kernel but disabled at boot time; * - %EAFNOSUPPORT: @rule_type is %LANDLOCK_RULE_NET_PORT but TCP/IP is not * supported by the running kernel; - * - %EINVAL: @flags is not 0, or inconsistent access in the rule (i.e. + * - %EINVAL: @flags is not 0; + * - %EINVAL: The rule accesses are inconsistent (i.e. * &landlock_path_beneath_attr.allowed_access or - * &landlock_net_port_attr.allowed_access is not a subset of the - * ruleset handled accesses), or &landlock_net_port_attr.port is - * greater than 65535; - * - %ENOMSG: Empty accesses (e.g. &landlock_path_beneath_attr.allowed_access); + * &landlock_net_port_attr.allowed_access is not a subset of the ruleset + * handled accesses) + * - %EINVAL: &landlock_net_port_attr.port is greater than 65535; + * - %ENOMSG: Empty accesses (e.g. &landlock_path_beneath_attr.allowed_access is + * 0); * - %EBADF: @ruleset_fd is not a file descriptor for the current thread, or a * member of @rule_attr is not a file descriptor as expected; * - %EBADFD: @ruleset_fd is not a ruleset file descriptor, or a member of * @rule_attr is not the expected file descriptor type; * - %EPERM: @ruleset_fd has no write access to the underlying ruleset; - * - %EFAULT: @rule_attr inconsistency. + * - %EFAULT: @rule_attr was not a valid address. */ SYSCALL_DEFINE4(landlock_add_rule, const int, ruleset_fd, const enum landlock_rule_type, rule_type, |