@@ -193,7 +193,8 @@ static bool check_ruleset_scope(const char *const env_var,
bool ret = true;
char *env_type_scope, *env_type_scope_next, *ipc_scoping_name;
- ruleset_attr->scoped &= ~LANDLOCK_SCOPED_ABSTRACT_UNIX_SOCKET;
+ ruleset_attr->scoped &= ~(LANDLOCK_SCOPED_ABSTRACT_UNIX_SOCKET |
+ LANDLOCK_SCOPED_SIGNAL);
env_type_scope = getenv(env_var);
/* scoping is not supported by the user */
if (!env_type_scope)
@@ -207,6 +208,8 @@ static bool check_ruleset_scope(const char *const env_var,
if (strcmp("a", ipc_scoping_name) == 0) {
ruleset_attr->scoped |=
LANDLOCK_SCOPED_ABSTRACT_UNIX_SOCKET;
+ } else if (strcmp("s", ipc_scoping_name) == 0) {
+ ruleset_attr->scoped |= LANDLOCK_SCOPED_SIGNAL;
} else {
fprintf(stderr, "Unsupported scoping \"%s\"\n",
ipc_scoping_name);
@@ -258,7 +261,8 @@ int main(const int argc, char *const argv[], char *const *const envp)
.handled_access_fs = access_fs_rw,
.handled_access_net = LANDLOCK_ACCESS_NET_BIND_TCP |
LANDLOCK_ACCESS_NET_CONNECT_TCP,
- .scoped = LANDLOCK_SCOPED_ABSTRACT_UNIX_SOCKET,
+ .scoped = LANDLOCK_SCOPED_ABSTRACT_UNIX_SOCKET |
+ LANDLOCK_SCOPED_SIGNAL,
};
if (argc < 2) {
@@ -295,7 +299,7 @@ int main(const int argc, char *const argv[], char *const *const envp)
"%s=\"/dev/null:/dev/full:/dev/zero:/dev/pts:/tmp\" "
"%s=\"9418\" "
"%s=\"80:443\" "
- "%s=\"a\" "
+ "%s=\"a:s\" "
"%s bash -i\n\n",
ENV_FS_RO_NAME, ENV_FS_RW_NAME, ENV_TCP_BIND_NAME,
ENV_TCP_CONNECT_NAME, ENV_SCOPED_NAME, argv[0]);
@@ -369,7 +373,8 @@ int main(const int argc, char *const argv[], char *const *const envp)
__attribute__((fallthrough));
case 5:
/* Removes LANDLOCK_SCOPED_ABSTRACT_UNIX_SOCKET for ABI < 6 */
- ruleset_attr.scoped &= ~LANDLOCK_SCOPED_ABSTRACT_UNIX_SOCKET;
+ ruleset_attr.scoped &= ~(LANDLOCK_SCOPED_ABSTRACT_UNIX_SOCKET |
+ LANDLOCK_SCOPED_SIGNAL);
fprintf(stderr,
"Hint: You should update the running kernel "
"to leverage Landlock features "
A sandboxer can receive the character "s" as input from the environment variable LL_SCOPE to restrict itself from sending a signal to a process outside its scoped domain. Example ======= Create a sandboxed shell and pass the character "s" to LL_SCOPED: LL_FS_RO=/ LL_FS_RW=. LL_SCOPED="s" ./sandboxer /bin/bash Try to send a SIGTRAP to a process with process ID <PID> through: kill -SIGTRAP <PID> The sandboxed process should not be able to send the signal. Signed-off-by: Tahera Fahimi <fahimitahera@gmail.com> --- samples/landlock/sandboxer.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-)