Subject: [merged] exit-call-disassociate_ctty-before-exit_task_namespaces.patch removed from -mm tree To: oleg@xxxxxxxxxx,avagin@xxxxxxxxxx,ebiederm@xxxxxxxxxxxx,jdike@xxxxxxxxxxx,mingo@xxxxxxx,peter@xxxxxxxxxxxxxxxxxx,sreeharsha@xxxxxxxxxxx,stable@xxxxxxxxxxxxxxx,viro@xxxxxxxxxxxxxxxxxx,mm-commits@xxxxxxxxxxxxxxx From: akpm@xxxxxxxxxxxxxxxxxxxx Date: Tue, 08 Apr 2014 14:14:40 -0700 The patch titled Subject: exit: call disassociate_ctty() before exit_task_namespaces() has been removed from the -mm tree. Its filename was exit-call-disassociate_ctty-before-exit_task_namespaces.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: Oleg Nesterov <oleg@xxxxxxxxxx> Subject: exit: call disassociate_ctty() before exit_task_namespaces() 8aac62706ada ("move exit_task_namespaces() outside of exit_notify()") breaks pppd and the exiting service crashes the kernel: BUG: unable to handle kernel NULL pointer dereference at 0000000000000028 IP: [<ffffffffa06985a3>] ppp_register_channel+0x13/0x20 [ppp_generic] ... Call Trace: [<ffffffffa06ab2ab>] ? ppp_asynctty_open+0x12b/0x170 [ppp_async] [<ffffffff812ec907>] ? tty_ldisc_open.isra.2+0x27/0x60 [<ffffffff812ed1d3>] ? tty_ldisc_hangup+0x1e3/0x220 [<ffffffff812e4614>] ? __tty_hangup+0x2c4/0x440 [<ffffffff812e56a1>] ? disassociate_ctty+0x61/0x270 [<ffffffff810483c2>] ? do_exit+0x7f2/0xa50 ppp_register_channel() needs ->net_ns and current->nsproxy == NULL. Move disassociate_ctty() before exit_task_namespaces(), it doesn't make sense to delay it after perf_event_exit_task() or cgroup_exit(). This also allows to use task_work_add() inside the (nontrivial) code paths in disassociate_ctty(). Investigated by Peter Hurley. Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx> Reported-by: Sree Harsha Totakura <sreeharsha@xxxxxxxxxxx> Cc: Peter Hurley <peter@xxxxxxxxxxxxxxxxxx> Cc: Sree Harsha Totakura <sreeharsha@xxxxxxxxxxx> Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx> Cc: Jeff Dike <jdike@xxxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxx> Cc: Andrey Vagin <avagin@xxxxxxxxxx> Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> [v3.10+] Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- kernel/exit.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff -puN kernel/exit.c~exit-call-disassociate_ctty-before-exit_task_namespaces kernel/exit.c --- a/kernel/exit.c~exit-call-disassociate_ctty-before-exit_task_namespaces +++ a/kernel/exit.c @@ -784,6 +784,8 @@ void do_exit(long code) exit_shm(tsk); exit_files(tsk); exit_fs(tsk); + if (group_dead) + disassociate_ctty(1); exit_task_namespaces(tsk); exit_task_work(tsk); check_stack_usage(); @@ -799,13 +801,9 @@ void do_exit(long code) cgroup_exit(tsk); - if (group_dead) - disassociate_ctty(1); - module_put(task_thread_info(tsk)->exec_domain->module); proc_exit_connector(tsk); - /* * FIXME: do that only when needed, using sched_exit tracepoint */ _ Patches currently in -mm which might be from oleg@xxxxxxxxxx are origin.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html