On Wed, Dec 9, 2020 at 8:29 PM Mickaël Salaün <mic@xxxxxxxxxxx> wrote: > Add a basic sandbox tool to launch a command which can only access a > whitelist of file hierarchies in a read-only or read-write way. I have to admit that I didn't really look at this closely before because it's just sample code... but I guess I should. You can add Reviewed-by: Jann Horn <jannh@xxxxxxxxxx> if you fix the following nits: [...] > diff --git a/samples/Kconfig b/samples/Kconfig [...] > +config SAMPLE_LANDLOCK > + bool "Build Landlock sample code" > + depends on HEADERS_INSTALL > + help > + Build a simple Landlock sandbox manager able to launch a process > + restricted by a user-defined filesystem access control. nit: s/filesystem access control/filesystem access control policy/ [...] > diff --git a/samples/landlock/sandboxer.c b/samples/landlock/sandboxer.c [...] > +/* > + * Simple Landlock sandbox manager able to launch a process restricted by a > + * user-defined filesystem access control. nit: s/filesystem access control/filesystem access control policy/ [...] > +int main(const int argc, char *const argv[], char *const *const envp) > +{ [...] > + if (argc < 2) { [...] > + fprintf(stderr, "* %s: list of paths allowed to be used in a read-only way.\n", > + ENV_FS_RO_NAME); > + fprintf(stderr, "* %s: list of paths allowed to be used in a read-write way.\n", > + ENV_FS_RO_NAME); s/ENV_FS_RO_NAME/ENV_FS_RW_NAME/ > + fprintf(stderr, "\nexample:\n" > + "%s=\"/bin:/lib:/usr:/proc:/etc:/dev/urandom\" " > + "%s=\"/dev/null:/dev/full:/dev/zero:/dev/pts:/tmp\" " > + "%s bash -i\n", > + ENV_FS_RO_NAME, ENV_FS_RW_NAME, argv[0]); > + return 1; > + } > + > + ruleset_fd = landlock_create_ruleset(&ruleset_attr, sizeof(ruleset_attr), 0); > + if (ruleset_fd < 0) { > + perror("Failed to create a ruleset"); > + switch (errno) { (Just as a note: In theory perror() can change the value of errno, as far as I know - so AFAIK you'd theoretically have to do something like: int errno_ = errno; perror("..."); switch (errno_) { ... } I'll almost certainly work fine as-is in practice though.)