From faeb9197669c23d983f6485d278b20f0194432f4 Mon Sep 17 00:00:00 2001 From: =?utf8?q?G=C3=BCnther=20Noack?= Date: Tue, 18 Oct 2022 20:22:15 +0200 Subject: [PATCH] samples/landlock: Extend sample tool to support LANDLOCK_ACCESS_FS_TRUNCATE MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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 Link: https://lore.kernel.org/r/20221018182216.301684-11-gnoack3000@gmail.com Signed-off-by: Mickaël Salaün --- 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 f29bb3c..fd4237c 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 @@ out_free_name: 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 " -- 2.7.4