[PATCH v10 10/11] samples/landlock: Extend sample tool to support LANDLOCK_ACCESS_FS_TRUNCATE
From: Günther Noack <hidden>
Date: 2022-10-18 18:23:21
Also in:
linux-fsdevel
Subsystem:
landlock security module, the rest · Maintainers:
Mickaël Salaün, Linus Torvalds
Update the sandboxer sample to restrict truncate actions. This is automatically enabled by default if the running kernel supports LANDLOCK_ACCESS_FS_TRUNCATE, except for the paths listed in the LL_FS_RW environment variable. Signed-off-by: Günther Noack <redacted> --- samples/landlock/sandboxer.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/samples/landlock/sandboxer.c b/samples/landlock/sandboxer.c
index f29bb3c72230..fd4237c64fb2 100644
--- a/samples/landlock/sandboxer.c
+++ b/samples/landlock/sandboxer.c@@ -76,7 +76,8 @@ static int parse_path(char *env_path, const char ***const path_list) #define ACCESS_FILE ( \ LANDLOCK_ACCESS_FS_EXECUTE | \ LANDLOCK_ACCESS_FS_WRITE_FILE | \ - LANDLOCK_ACCESS_FS_READ_FILE) + LANDLOCK_ACCESS_FS_READ_FILE | \ + LANDLOCK_ACCESS_FS_TRUNCATE) /* clang-format on */
@@ -160,11 +161,12 @@ static int populate_ruleset(const char *const env_var, const int ruleset_fd, LANDLOCK_ACCESS_FS_MAKE_FIFO | \ LANDLOCK_ACCESS_FS_MAKE_BLOCK | \ LANDLOCK_ACCESS_FS_MAKE_SYM | \ - LANDLOCK_ACCESS_FS_REFER) + LANDLOCK_ACCESS_FS_REFER | \ + LANDLOCK_ACCESS_FS_TRUNCATE) /* clang-format on */ -#define LANDLOCK_ABI_LAST 2 +#define LANDLOCK_ABI_LAST 3 int main(const int argc, char *const argv[], char *const *const envp) {
@@ -234,6 +236,10 @@ int main(const int argc, char *const argv[], char *const *const envp) case 1: /* Removes LANDLOCK_ACCESS_FS_REFER for ABI < 2 */ ruleset_attr.handled_access_fs &= ~LANDLOCK_ACCESS_FS_REFER; + __attribute__((fallthrough)); + case 2: + /* Removes LANDLOCK_ACCESS_FS_TRUNCATE for ABI < 3 */ + ruleset_attr.handled_access_fs &= ~LANDLOCK_ACCESS_FS_TRUNCATE; fprintf(stderr, "Hint: You should update the running kernel "
--
2.38.0