wait_noreap_copyout(): check for ->wo_info != NULL
Current behaviour of sys_waitid() looks odd. If user passes infop ==
NULL, sys_waitid() returns success. When user additionally specifies flag
WNOWAIT, sys_waitid() returns -EFAULT on the same conditions. When user
combines WNOWAIT with WCONTINUED, sys_waitid() again returns success.
This patch adds check for ->wo_info in wait_noreap_copyout().
User-visible change: starting from this commit, sys_waitid() always checks
infop != NULL and does not fail if it is NULL.
Signed-off-by: Vitaly Mayatskikh <v.mayatskih@gmail.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/kernel/exit.c b/kernel/exit.c
index 2cc69eb..6c75ff83 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -1140,18 +1140,20 @@
put_task_struct(p);
infop = wo->wo_info;
- if (!retval)
- retval = put_user(SIGCHLD, &infop->si_signo);
- if (!retval)
- retval = put_user(0, &infop->si_errno);
- if (!retval)
- retval = put_user((short)why, &infop->si_code);
- if (!retval)
- retval = put_user(pid, &infop->si_pid);
- if (!retval)
- retval = put_user(uid, &infop->si_uid);
- if (!retval)
- retval = put_user(status, &infop->si_status);
+ if (infop) {
+ if (!retval)
+ retval = put_user(SIGCHLD, &infop->si_signo);
+ if (!retval)
+ retval = put_user(0, &infop->si_errno);
+ if (!retval)
+ retval = put_user((short)why, &infop->si_code);
+ if (!retval)
+ retval = put_user(pid, &infop->si_pid);
+ if (!retval)
+ retval = put_user(uid, &infop->si_uid);
+ if (!retval)
+ retval = put_user(status, &infop->si_status);
+ }
if (!retval)
retval = pid;
return retval;