diff options
| -rw-r--r-- | security/smack/smack_lsm.c | 84 |
1 files changed, 71 insertions, 13 deletions
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index b23fbdd4cdad..4d6f37644baa 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -157,6 +157,54 @@ static int smk_copy_rules(struct list_head *nhead, struct list_head *ohead, return rc; } +/** + * smk_ptrace_mode - helper function for converting PTRACE_MODE_* into MAY_* + * @mode - input mode in form of PTRACE_MODE_* + * + * Returns a converted MAY_* mode usable by smack rules + */ +static inline unsigned int smk_ptrace_mode(unsigned int mode) +{ + switch (mode) { + case PTRACE_MODE_READ: + return MAY_READ; + case PTRACE_MODE_ATTACH: + return MAY_READWRITE; + } + + return 0; +} + +/** + * smk_ptrace_rule_check - helper for ptrace access + * @tracer: tracer process + * @tracee_label: label of the process that's about to be traced + * @mode: ptrace attachment mode (PTRACE_MODE_*) + * @func: name of the function that called us, used for audit + * + * Returns 0 on access granted, -error on error + */ +static int smk_ptrace_rule_check(struct task_struct *tracer, char *tracee_label, + unsigned int mode, const char *func) +{ + int rc; + struct smk_audit_info ad, *saip = NULL; + struct task_smack *tsp; + struct smack_known *skp; + + if ((mode & PTRACE_MODE_NOAUDIT) == 0) { + smk_ad_init(&ad, func, LSM_AUDIT_DATA_TASK); + smk_ad_setfield_u_tsk(&ad, tracer); + saip = &ad; + } + + tsp = task_security(tracer); + skp = smk_of_task(tsp); + + rc = smk_tskacc(tsp, tracee_label, smk_ptrace_mode(mode), saip); + return rc; +} + /* * LSM hooks. * We he, that is fun! @@ -165,16 +213,15 @@ static int smk_copy_rules(struct list_head *nhead, struct list_head *ohead, /** * smack_ptrace_access_check - Smack approval on PTRACE_ATTACH * @ctp: child task pointer - * @mode: ptrace attachment mode + * @mode: ptrace attachment mode (PTRACE_MODE_*) * * Returns 0 if access is OK, an error code otherwise * - * Do the capability checks, and require read and write. + * Do the capability checks. */ static int smack_ptrace_access_check(struct task_struct *ctp, unsigned int mode) { int rc; - struct smk_audit_info ad; struct smack_known *skp; rc = cap_ptrace_access_check(ctp, mode); @@ -182,10 +229,8 @@ static int smack_ptrace_access_check(struct task_struct *ctp, unsigned int mode) return rc; skp = smk_of_task(task_security(ctp)); - smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK); - smk_ad_setfield_u_tsk(&ad, ctp); - rc = smk_curacc(skp->smk_known, mode, &ad); + rc = smk_ptrace_rule_check(current, skp->smk_known, mode, __func__); return rc; } @@ -195,12 +240,11 @@ static int smack_ptrace_access_check(struct task_struct *ctp, unsigned int mode) * * Returns 0 if access is OK, an error code otherwise * - * Do the capability checks, and require read and write. + * Do the capability checks, and require PTRACE_MODE_ATTACH. */ static int smack_ptrace_traceme(struct task_struct *ptp) { int rc; - struct smk_audit_info ad; struct smack_known *skp; rc = cap_ptrace_traceme(ptp); @@ -208,10 +252,9 @@ static int smack_ptrace_traceme(struct task_struct *ptp) return rc; skp = smk_of_task(current_security()); - smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK); - smk_ad_setfield_u_tsk(&ad, ptp); - rc = smk_tskacc(ptp, skp->smk_known, MAY_READWRITE, &ad); + rc = smk_ptrace_rule_check(ptp, skp->smk_known, + PTRACE_MODE_ATTACH, __func__); return rc; } @@ -455,7 +498,7 @@ static int smack_sb_statfs(struct dentry *dentry) * smack_bprm_set_creds - set creds for exec * @bprm: the exec information * - * Returns 0 if it gets a blob, -ENOMEM otherwise + * Returns 0 if it gets a blob, -EPERM if exec forbidden and -ENOMEM otherwise */ static int smack_bprm_set_creds(struct linux_binprm *bprm) { @@ -475,7 +518,22 @@ static int smack_bprm_set_creds(struct linux_binprm *bprm) if (isp->smk_task == NULL || isp->smk_task == bsp->smk_task) return 0; - if (bprm->unsafe) + if (bprm->unsafe & (LSM_UNSAFE_PTRACE | LSM_UNSAFE_PTRACE_CAP)) { + struct task_struct *tracer; + rc = 0; + + rcu_read_lock(); + tracer = ptrace_parent(current); + if (likely(tracer != NULL)) + rc = smk_ptrace_rule_check(tracer, + isp->smk_task->smk_known, + PTRACE_MODE_ATTACH, + __func__); + rcu_read_unlock(); + + if (rc != 0) + return rc; + } else if (bprm->unsafe) return -EPERM; bsp->smk_task = isp->smk_task; |