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| author | Eric W. Biederman <ebiederm@xmission.com> | 2020-03-22 15:46:24 -0500 |
|---|---|---|
| committer | Eric W. Biederman <ebiederm@xmission.com> | 2020-05-20 14:45:31 -0500 |
| commit | b8bff599261c930630385ee21d3f98e7ce7d4843 (patch) | |
| tree | abe467d5124f1df78e2d2383068c90f518a16069 /security/tomoyo | |
| parent | 87b047d2be417b271d80f5e490a825c6fd53ecad (diff) | |
| download | lwn-b8bff599261c930630385ee21d3f98e7ce7d4843.tar.gz lwn-b8bff599261c930630385ee21d3f98e7ce7d4843.zip | |
exec: Factor security_bprm_creds_for_exec out of security_bprm_set_creds
Today security_bprm_set_creds has several implementations:
apparmor_bprm_set_creds, cap_bprm_set_creds, selinux_bprm_set_creds,
smack_bprm_set_creds, and tomoyo_bprm_set_creds.
Except for cap_bprm_set_creds they all test bprm->called_set_creds and
return immediately if it is true. The function cap_bprm_set_creds
ignores bprm->calld_sed_creds entirely.
Create a new LSM hook security_bprm_creds_for_exec that is called just
before prepare_binprm in __do_execve_file, resulting in a LSM hook
that is called exactly once for the entire of exec. Modify the bits
of security_bprm_set_creds that only want to be called once per exec
into security_bprm_creds_for_exec, leaving only cap_bprm_set_creds
behind.
Remove bprm->called_set_creds all of it's former users have been moved
to security_bprm_creds_for_exec.
Add or upate comments a appropriate to bring them up to date and
to reflect this change.
Link: https://lkml.kernel.org/r/87v9kszrzh.fsf_-_@x220.int.ebiederm.org
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Casey Schaufler <casey@schaufler-ca.com> # For the LSM and Smack bits
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Diffstat (limited to 'security/tomoyo')
| -rw-r--r-- | security/tomoyo/tomoyo.c | 12 |
1 files changed, 3 insertions, 9 deletions
diff --git a/security/tomoyo/tomoyo.c b/security/tomoyo/tomoyo.c index 716c92ec941a..f9adddc42ac8 100644 --- a/security/tomoyo/tomoyo.c +++ b/security/tomoyo/tomoyo.c @@ -63,21 +63,15 @@ static void tomoyo_bprm_committed_creds(struct linux_binprm *bprm) #ifndef CONFIG_SECURITY_TOMOYO_OMIT_USERSPACE_LOADER /** - * tomoyo_bprm_set_creds - Target for security_bprm_set_creds(). + * tomoyo_bprm_for_exec - Target for security_bprm_creds_for_exec(). * * @bprm: Pointer to "struct linux_binprm". * * Returns 0. */ -static int tomoyo_bprm_set_creds(struct linux_binprm *bprm) +static int tomoyo_bprm_creds_for_exec(struct linux_binprm *bprm) { /* - * Do only if this function is called for the first time of an execve - * operation. - */ - if (bprm->called_set_creds) - return 0; - /* * Load policy if /sbin/tomoyo-init exists and /sbin/init is requested * for the first time. */ @@ -539,7 +533,7 @@ static struct security_hook_list tomoyo_hooks[] __lsm_ro_after_init = { LSM_HOOK_INIT(task_alloc, tomoyo_task_alloc), LSM_HOOK_INIT(task_free, tomoyo_task_free), #ifndef CONFIG_SECURITY_TOMOYO_OMIT_USERSPACE_LOADER - LSM_HOOK_INIT(bprm_set_creds, tomoyo_bprm_set_creds), + LSM_HOOK_INIT(bprm_creds_for_exec, tomoyo_bprm_creds_for_exec), #endif LSM_HOOK_INIT(bprm_check_security, tomoyo_bprm_check_security), LSM_HOOK_INIT(file_fcntl, tomoyo_file_fcntl), |