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| author |   Oleg Nesterov <oleg@tv-sign.ru> | 2006-10-02 02:18:59 -0700 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@g5.osdl.org> | 2006-10-02 07:57:25 -0700 |
| commit | 1a657f78dcc8ea7c53eaa1f2a45ea2315738c15f (patch) | |
| tree | a19972027792082fed505c8d540f7d877e37c0ab /kernel/pid.c | |
| parent | [PATCH] proc: comment what proc_fill_cache does (diff) | |
| download | linux-dev-1a657f78dcc8ea7c53eaa1f2a45ea2315738c15f.tar.xz linux-dev-1a657f78dcc8ea7c53eaa1f2a45ea2315738c15f.zip | |
[PATCH] introduce get_task_pid() to fix unsafe get_pid()
proc_pid_make_inode:
ei->pid = get_pid(task_pid(task));
I think this is not safe. get_pid() can be preempted after checking "pid
!= NULL". Then the task exits, does detach_pid(), and RCU frees the pid.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'kernel/pid.c')
| -rw-r--r-- | kernel/pid.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/kernel/pid.c b/kernel/pid.c index e4779bbb2058..b914392085f9 100644 --- a/kernel/pid.c +++ b/kernel/pid.c @@ -304,6 +304,15 @@ struct task_struct *find_task_by_pid_type(int type, int nr) EXPORT_SYMBOL(find_task_by_pid_type); +struct pid *get_task_pid(struct task_struct *task, enum pid_type type) +{ + struct pid *pid; + rcu_read_lock(); + pid = get_pid(task->pids[type].pid); + rcu_read_unlock(); + return pid; +} + struct task_struct *fastcall get_pid_task(struct pid *pid, enum pid_type type) { struct task_struct *result; |