fix infoleak in waitid(2)
authorAl Viro <viro@zeniv.linux.org.uk>
Fri, 29 Sep 2017 17:43:15 +0000 (13:43 -0400)
committerAl Viro <viro@zeniv.linux.org.uk>
Fri, 29 Sep 2017 17:43:15 +0000 (13:43 -0400)
commit6c85501f2fabcfc4fc6ed976543d252c4eaf4be9
tree7ae62970c63295669f955f60b78dbada3e564d30
parentb776e4b1a990045a7c70798f1f353c3160c26594
fix infoleak in waitid(2)

kernel_waitid() can return a PID, an error or 0.  rusage is filled in the first
case and waitid(2) rusage should've been copied out exactly in that case, *not*
whenever kernel_waitid() has not returned an error.  Compat variant shares that
braino; none of kernel_wait4() callers do, so the below ought to fix it.

Reported-and-tested-by: Alexander Potapenko <glider@google.com>
Fixes: ce72a16fa705 ("wait4(2)/waitid(2): separate copying rusage to userland")
Cc: stable@vger.kernel.org # v4.13
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
kernel/exit.c