Unverified Commit faeb9197 authored by Günther Noack's avatar Günther Noack Committed by Mickaël Salaün
Browse files

samples/landlock: Extend sample tool to support LANDLOCK_ACCESS_FS_TRUNCATE 



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: default avatarGünther Noack <gnoack3000@gmail.com>
Link: https://lore.kernel.org/r/20221018182216.301684-11-gnoack3000@gmail.com


Signed-off-by: default avatarMickaël Salaün <mic@digikod.net>
parent 0d8c658b

samples/landlock/sandboxer.c

+9 −3
Original line number Diff line number Diff line
@@ -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 "