From 0c6181cb301fd04a5800920ba423be753b0a4a01 Mon Sep 17 00:00:00 2001 From: Paul Moore Date: Wed, 30 Mar 2016 21:41:21 -0400 Subject: selinux: consolidate the ptrace parent lookup code We lookup the tracing parent in two places, using effectively the same code, let's consolidate it. Signed-off-by: Paul Moore --- security/selinux/hooks.c | 38 +++++++++++++++++--------------------- 1 file changed, 17 insertions(+), 21 deletions(-) diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index dd1fbea37b78..5003b5aa3b43 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -2229,6 +2229,20 @@ static int selinux_vm_enough_memory(struct mm_struct *mm, long pages) /* binprm security operations */ +static u32 ptrace_parent_sid(struct task_struct *task) +{ + u32 sid = 0; + struct task_struct *tracer; + + rcu_read_lock(); + tracer = ptrace_parent(task); + if (tracer) + sid = task_sid(tracer); + rcu_read_unlock(); + + return sid; +} + static int check_nnp_nosuid(const struct linux_binprm *bprm, const struct task_security_struct *old_tsec, const struct task_security_struct *new_tsec) @@ -2350,18 +2364,7 @@ static int selinux_bprm_set_creds(struct linux_binprm *bprm) * changes its SID has the appropriate permit */ if (bprm->unsafe & (LSM_UNSAFE_PTRACE | LSM_UNSAFE_PTRACE_CAP)) { - struct task_struct *tracer; - struct task_security_struct *sec; - u32 ptsid = 0; - - rcu_read_lock(); - tracer = ptrace_parent(current); - if (likely(tracer != NULL)) { - sec = __task_cred(tracer)->security; - ptsid = sec->sid; - } - rcu_read_unlock(); - + u32 ptsid = ptrace_parent_sid(current); if (ptsid != 0) { rc = avc_has_perm(ptsid, new_tsec->sid, SECCLASS_PROCESS, @@ -5677,7 +5680,6 @@ static int selinux_setprocattr(struct task_struct *p, char *name, void *value, size_t size) { struct task_security_struct *tsec; - struct task_struct *tracer; struct cred *new; u32 sid = 0, ptsid; int error; @@ -5784,14 +5786,8 @@ static int selinux_setprocattr(struct task_struct *p, /* Check for ptracing, and update the task SID if ok. Otherwise, leave SID unchanged and fail. */ - ptsid = 0; - rcu_read_lock(); - tracer = ptrace_parent(p); - if (tracer) - ptsid = task_sid(tracer); - rcu_read_unlock(); - - if (tracer) { + ptsid = ptrace_parent_sid(p); + if (ptsid != 0) { error = avc_has_perm(ptsid, sid, SECCLASS_PROCESS, PROCESS__PTRACE, NULL); if (error) -- cgit v1.2.3-59-g8ed1b