setpgid(child) fails if the child was forked by sub-thread

Spotted by Marcin Kowalczyk <qrczak@knm.org.pl>.

sys_setpgid(child) fails if the child was forked by sub-thread.

Fix the "is it our child" check. The previous commit
ee0acf90d3 was not complete.

(this patch asks for the new same_thread_group() helper, but mainline doesn't
 have it yet).

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Acked-by: Roland McGrath <roland@redhat.com>
Cc: <stable@kernel.org>
Tested-by: "Marcin 'Qrczak' Kowalczyk" <qrczak@knm.org.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Oleg Nesterov 2007-08-30 23:56:27 -07:00 committed by Linus Torvalds
parent 5d540fb715
commit b07e35f94a

View File

@ -1442,7 +1442,6 @@ asmlinkage long sys_times(struct tms __user * tbuf)
* Auch. Had to add the 'did_exec' flag to conform completely to POSIX.
* LBT 04.03.94
*/
asmlinkage long sys_setpgid(pid_t pid, pid_t pgid)
{
struct task_struct *p;
@ -1470,7 +1469,7 @@ asmlinkage long sys_setpgid(pid_t pid, pid_t pgid)
if (!thread_group_leader(p))
goto out;
if (p->real_parent == group_leader) {
if (p->real_parent->tgid == group_leader->tgid) {
err = -EPERM;
if (task_session(p) != task_session(group_leader))
goto out;