On 8/22/2022 12:17 PM, Günther Noack wrote:
Hi!
Very exciting to see! Thank you for sending this! :)
I'm just throwing in some comments based on the very similar truncate patch set, in the hope that it helps. (But obviously, Mickaël Salaün has the last word on this code.)
Slightly higher level question: Should we start to group the functionality of multiple LSM hooks under one Landlock flag? (Will it be harder to change the LSM hook interface in the future if we continue to add one flag per hook? Or is this structure already exposed to userspace by other LSMs?)
I'm not a landlock expert. The question is nonsensical, yet somewhat frightening nonetheless. Could you put just a touch more context into what you're asking for?
For example, some of the "missing" operations listed on the Landlock documentation could also be grouped roughly as:
Modifying files:
- truncate
Modifying file metadata:
- chmod
- chown
- setxattr
- utime
Observing files (check presence and file metadata):
- access
- stat
- readlink, following links (can observe symlink presence)
- chdir (can observe dir presence and 'x' attribute)
Ungrouped:
- flock
- ioctl
- fcntl
Do you have opinions on this?
—Günther
On Mon, Aug 22, 2022 at 07:46:56PM +0800, Xiu Jianfeng wrote:
hi, this patchset adds chmod and chown support for landlock
Xiu Jianfeng (5): landlock: expand access_mask_t to u32 type landlock: add chmod and chown support landlock/selftests: add selftests for chmod and chown landlock/samples: add chmod and chown support landlock: update chmod and chown support in document
Documentation/userspace-api/landlock.rst | 8 +- include/uapi/linux/landlock.h | 8 +- samples/landlock/sandboxer.c | 12 +- security/landlock/fs.c | 16 +- security/landlock/limits.h | 2 +- security/landlock/ruleset.h | 2 +- security/landlock/syscalls.c | 2 +- tools/testing/selftests/landlock/base_test.c | 2 +- tools/testing/selftests/landlock/fs_test.c | 234 ++++++++++++++++++- 9 files changed, 274 insertions(+), 12 deletions(-)
-- 2.17.1
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