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| author | Eric W. Biederman <ebiederm@xmission.com> | 2020-03-22 21:46:24 +0100 |
|---|---|---|
| committer | Eric W. Biederman <ebiederm@xmission.com> | 2020-05-20 21:45:31 +0200 |
| commit | b8bff599261c930630385ee21d3f98e7ce7d4843 (patch) | |
| tree | abe467d5124f1df78e2d2383068c90f518a16069 /security/smack | |
| parent | exec: Teach prepare_exec_creds how exec treats uids & gids (diff) | |
| download | linux-b8bff599261c930630385ee21d3f98e7ce7d4843.tar.xz linux-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/smack')
| -rw-r--r-- | security/smack/smack_lsm.c | 9 |
1 files changed, 3 insertions, 6 deletions
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index 8c61d175e195..0ac8f4518d07 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -891,12 +891,12 @@ static int smack_sb_statfs(struct dentry *dentry) */ /** - * smack_bprm_set_creds - set creds for exec + * smack_bprm_creds_for_exec - Update bprm->cred if needed for exec * @bprm: the exec information * * Returns 0 if it gets a blob, -EPERM if exec forbidden and -ENOMEM otherwise */ -static int smack_bprm_set_creds(struct linux_binprm *bprm) +static int smack_bprm_creds_for_exec(struct linux_binprm *bprm) { struct inode *inode = file_inode(bprm->file); struct task_smack *bsp = smack_cred(bprm->cred); @@ -904,9 +904,6 @@ static int smack_bprm_set_creds(struct linux_binprm *bprm) struct superblock_smack *sbsp; int rc; - if (bprm->called_set_creds) - return 0; - isp = smack_inode(inode); if (isp->smk_task == NULL || isp->smk_task == bsp->smk_task) return 0; @@ -4598,7 +4595,7 @@ static struct security_hook_list smack_hooks[] __lsm_ro_after_init = { LSM_HOOK_INIT(sb_statfs, smack_sb_statfs), LSM_HOOK_INIT(sb_set_mnt_opts, smack_set_mnt_opts), - LSM_HOOK_INIT(bprm_set_creds, smack_bprm_set_creds), + LSM_HOOK_INIT(bprm_creds_for_exec, smack_bprm_creds_for_exec), LSM_HOOK_INIT(inode_alloc_security, smack_inode_alloc_security), LSM_HOOK_INIT(inode_init_security, smack_inode_init_security), |