bianbu-repo-mirror/bianbu-linux-6.6
1
0
Fork 0
mirror of https://gitee.com/bianbu-linux/linux-6.6 synced 2025-04-26 14:17:26 -04:00
Code Issues Projects Releases Packages Wiki Activity Actions

pids: make task_tgid_nr_ns() safe

Browse source 
This was reported many times, and this was even mentioned in commit
52ee2dfdd4 ("pids: refactor vnr/nr_ns helpers to make them safe") but
somehow nobody bothered to fix the obvious problem: task_tgid_nr_ns() is
not safe because task->group_leader points to nowhere after the exiting
task passes exit_notify(), rcu_read_lock() can not help.

We really need to change __unhash_process() to nullify group_leader,
parent, and real_parent, but this needs some cleanups.  Until then we
can turn task_tgid_nr_ns() into another user of __task_pid_nr_ns() and
fix the problem.

Reported-by: Troy Kensinger <tkensinger@google.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Oleg Nesterov 2017-08-21 17:35:02 +02:00 • committed by Linus Torvalds
parent 14ccee78fc
commit dd1c1f2f20
3 changed files with 34 additions and 32 deletions
Download patch file Download diff file Expand all files Collapse all files

4
include/linux/pid.h
View file

@ -8,7 +8,9 @@ enum pid_type
PIDTYPE_PID,
PIDTYPE_PGID,
PIDTYPE_SID,
PIDTYPE_MAX
PIDTYPE_MAX,
/* only valid to __task_pid_nr_ns() */
__PIDTYPE_TGID
};
/*