2007-08-22 16:52:50

by Oleg Nesterov

Subject: [PATCH] setpgid(child) fails if the child was forked by sub-thread

Spotted by Marcin Kowalczyk <[email protected]>.

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

Fix the "is it our child" check. The previous commit
ee0acf90d320c29916ba8c5c1b2e908d81f5057d 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 <[email protected]>

--- t/kernel/sys.c~SETPGID 2007-08-09 19:59:27.000000000 +0400
+++ t/kernel/sys.c 2007-08-22 20:11:23.000000000 +0400
@@ -1442,7 +1442,6 @@ asmlinkage long sys_times(struct tms __u
* 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, p
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;

2007-08-22 17:10:21

by Randy Dunlap

Subject: Re: [PATCH] setpgid(child) fails if the child was forked by sub-thread

On Wed, 22 Aug 2007 20:55:39 +0400 Oleg Nesterov wrote:


so "fixes http://bugzilla.kernel.org/show_bug.cgi?id=8921" ??


> Spotted by Marcin Kowalczyk <[email protected]>.
>
> sys_setpgid(child) fails if the child was forked by sub-thread.
>
> Fix the "is it our child" check. The previous commit
> ee0acf90d320c29916ba8c5c1b2e908d81f5057d 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 <[email protected]>
>
> --- t/kernel/sys.c~SETPGID 2007-08-09 19:59:27.000000000 +0400
> +++ t/kernel/sys.c 2007-08-22 20:11:23.000000000 +0400
> @@ -1442,7 +1442,6 @@ asmlinkage long sys_times(struct tms __u
> * 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, p
> 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;
>
> -

---
~Randy
*** Remember to use Documentation/SubmitChecklist when testing your code ***

2007-08-22 17:23:18

by Oleg Nesterov

Subject: Re: [PATCH] setpgid(child) fails if the child was forked by sub-thread

On 08/22, Randy Dunlap wrote:
>
> On Wed, 22 Aug 2007 20:55:39 +0400 Oleg Nesterov wrote:
>
>
> so "fixes http://bugzilla.kernel.org/show_bug.cgi?id=8921" ??

Hopefully yes... should I add some note at /bugzilla.kernel.org?

Oleg.

2007-08-22 17:32:39

by Randy Dunlap

Subject: Re: [PATCH] setpgid(child) fails if the child was forked by sub-thread

On Wed, 22 Aug 2007 21:24:36 +0400 Oleg Nesterov wrote:

> On 08/22, Randy Dunlap wrote:
> >
> > On Wed, 22 Aug 2007 20:55:39 +0400 Oleg Nesterov wrote:
> >
> >
> > so "fixes http://bugzilla.kernel.org/show_bug.cgi?id=8921" ??
>
> Hopefully yes... should I add some note at /bugzilla.kernel.org?

I think that it can wait until Marcin confirms that it's fixed
(if he does so soon), then mark 8921 as fixed.


---
~Randy
*** Remember to use Documentation/SubmitChecklist when testing your code ***

2007-08-23 09:26:33

by Marcin 'Qrczak' Kowalczyk

Subject: Re: [PATCH] setpgid(child) fails if the child was forked by sub-thread

Dnia 22-08-2007, ?r o godzinie 10:30 -0700, Randy Dunlap napisa?(a):

> > > so "fixes http://bugzilla.kernel.org/show_bug.cgi?id=8921" ??
> >
> > Hopefully yes... should I add some note at /bugzilla.kernel.org?
>
> I think that it can wait until Marcin confirms that it's fixed
> (if he does so soon), then mark 8921 as fixed.

Yes, it's fixed. Thank you!

--
__("< Marcin Kowalczyk
\__/ [email protected]
^^ http://qrnik.knm.org.pl/~qrczak/