Gh0st
/
linux
mirror of https://github.com/torvalds/linux.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

selftests/namespaces: sixth listns() permission test 

Test that we can see user namespaces we have CAP_SYS_ADMIN inside of.
This is different from seeing namespaces owned by a user namespace.

Link: https://patch.msgid.link/20251029-work-namespace-nstree-listns-v4-53-2e6f823ebdc0@kernel.org
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
This commit is contained in:
Christian Brauner 2025-10-29 13:21:06 +01:00
parent 1c28817eb3
commit cff66421ee
No known key found for this signature in database
GPG Key ID: 91C61BC06578DCA2
1 changed files with 87 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

87
tools/testing/selftests/namespaces/listns_permissions_test.c
View File

@ -561,4 +561,91 @@ TEST(listns_parent_userns_cap_sys_admin)
count);
}
/*
* Test that we can see user namespaces we have CAP_SYS_ADMIN inside of.
* This is different from seeing namespaces owned by a user namespace.
*/
TEST(listns_cap_sys_admin_inside_userns)
{
int pipefd[2];
pid_t pid;
int status;
bool found_ours;
ASSERT_EQ(pipe(pipefd), 0);
pid = fork();
ASSERT_GE(pid, 0);
if (pid == 0) {
int fd;
__u64 our_userns_id;
struct ns_id_req req;
__u64 ns_ids[100];
ssize_t ret;
bool found_ours;
close(pipefd[0]);
/* Create user namespace - we have CAP_SYS_ADMIN inside it */
if (setup_userns() < 0) {
close(pipefd[1]);
exit(1);
}
/* Get our user namespace ID */
fd = open("/proc/self/ns/user", O_RDONLY);
if (fd < 0) {
close(pipefd[1]);
exit(1);
}
if (ioctl(fd, NS_GET_ID, &our_userns_id) < 0) {
close(fd);
close(pipefd[1]);
exit(1);
}
close(fd);
/* List all user namespaces globally */
req.size = sizeof(req);
req.spare = 0;
req.ns_id = 0;
req.ns_type = CLONE_NEWUSER;
req.spare2 = 0;
req.user_ns_id = 0;
ret = sys_listns(&req, ns_ids, ARRAY_SIZE(ns_ids), 0);
/* We should be able to see our own user namespace */
found_ours = false;
if (ret > 0) {
for (ssize_t i = 0; i < ret; i++) {
if (ns_ids[i] == our_userns_id) {
found_ours = true;
break;
}
}
}
write(pipefd[1], &found_ours, sizeof(found_ours));
close(pipefd[1]);
exit(0);
}
/* Parent */
close(pipefd[1]);
found_ours = false;
read(pipefd[0], &found_ours, sizeof(found_ours));
close(pipefd[0]);
waitpid(pid, &status, 0);
ASSERT_TRUE(WIFEXITED(status));
ASSERT_EQ(WEXITSTATUS(status), 0);
ASSERT_TRUE(found_ours);
TH_LOG("Process can see user namespace it has CAP_SYS_ADMIN inside of");
}
TEST_HARNESS_MAIN