Re: [PATCH v9 4/5] sample/Landlock: Support abstract unix socket restriction
From: Mickaël Salaün <mic@digikod.net>
Date: 2024-08-19 19:47:55
Also in:
linux-security-module, lkml
On Wed, Aug 14, 2024 at 12:22:22AM -0600, Tahera Fahimi wrote:
A sandboxer can receive the character "a" as input from the environment variable LL_SCOPE to restrict the abstract unix sockets from connecting to a process outside its scoped domain. Example ======= Create an abstract unix socket to listen with socat(1): socat abstract-listen:mysocket - Create a sandboxed shell and pass the character "a" to LL_SCOPED: LL_FS_RO=/ LL_FS_RW=. LL_SCOPED="a" ./sandboxer /bin/bash If the sandboxed process tries to connect to the listening socket with command "socat - abstract-connect:mysocket", the connection will fail. Signed-off-by: Tahera Fahimi <redacted> ---
quoted hunk ↗ jump to hunk
@@ -358,6 +403,11 @@ int main(const int argc, char *const argv[], char *const *const envp) ~LANDLOCK_ACCESS_NET_CONNECT_TCP; } + if (abi >= 6 && !check_ruleset_scope(ENV_SCOPED_NAME, &ruleset_attr)) { + perror("Unsupported IPC scoping requested");
If LL_SCOPE="", the sandboxer prints: "Unsupported IPC scoping requested: Success"
+ return 1;
+ }
+
ruleset_fd =
landlock_create_ruleset(&ruleset_attr, sizeof(ruleset_attr), 0);
if (ruleset_fd < 0) {
--
2.34.1