diff options
| author | Roland McGrath <roland@redhat.com> | 2007-05-06 14:50:20 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-05-07 12:12:57 -0700 |
| commit | 73243284463a761e04d69d22c7516b2be7de096c (patch) | |
| tree | 1a823a613568b48d3a4db694aa02ce380643a3dc /kernel | |
| parent | 906e0be197232c219197d058ef5095baa7764cd4 (diff) | |
Return EPERM not ECHILD on security_task_wait failure
wait* syscalls return -ECHILD even when an individual PID of a live child
was requested explicitly, when security_task_wait denies the operation.
This means that something like a broken SELinux policy can produce an
unexpected failure that looks just like a bug with wait or ptrace or
something.
This patch makes do_wait return -EACCES (or other appropriate error returned
from security_task_wait() instead of -ECHILD if some children were ruled out
solely because security_task_wait failed.
[jmorris@namei.org: switch error code to EACCES]
Signed-off-by: Roland McGrath <roland@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/exit.c | 17 |
1 files changed, 15 insertions, 2 deletions
diff --git a/kernel/exit.c b/kernel/exit.c index b55ed4cc9104..92369240d91d 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -1033,6 +1033,8 @@ asmlinkage void sys_exit_group(int error_code) static int eligible_child(pid_t pid, int options, struct task_struct *p) { + int err; + if (pid > 0) { if (p->pid != pid) return 0; @@ -1066,8 +1068,9 @@ static int eligible_child(pid_t pid, int options, struct task_struct *p) if (delay_group_leader(p)) return 2; - if (security_task_wait(p)) - return 0; + err = security_task_wait(p); + if (err) + return err; return 1; } @@ -1449,6 +1452,7 @@ static long do_wait(pid_t pid, int options, struct siginfo __user *infop, DECLARE_WAITQUEUE(wait, current); struct task_struct *tsk; int flag, retval; + int allowed, denied; add_wait_queue(¤t->signal->wait_chldexit,&wait); repeat: @@ -1457,6 +1461,7 @@ repeat: * match our criteria, even if we are not able to reap it yet. */ flag = 0; + allowed = denied = 0; current->state = TASK_INTERRUPTIBLE; read_lock(&tasklist_lock); tsk = current; @@ -1472,6 +1477,12 @@ repeat: if (!ret) continue; + if (unlikely(ret < 0)) { + denied = ret; + continue; + } + allowed = 1; + switch (p->state) { case TASK_TRACED: /* @@ -1570,6 +1581,8 @@ check_continued: goto repeat; } retval = -ECHILD; + if (unlikely(denied) && !allowed) + retval = denied; end: current->state = TASK_RUNNING; remove_wait_queue(¤t->signal->wait_chldexit,&wait); |