On Wed, Dec 09, 2020 at 07:21:00PM +0800, Yahu Gao wrote: > Get the staus of task from the pointer of proc inode directly is not > safe. The function get_proc_task make it happen in RCU protection.
This is completely broken, get_proc_task() acquires a reference to task_struct; your patch is an instant leak. > Signed-off-by: Yahu Gao <[email protected]> > --- > fs/proc/base.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/fs/proc/base.c b/fs/proc/base.c > index 1bc9bcdef09f..05f33bb35067 100644 > --- a/fs/proc/base.c > +++ b/fs/proc/base.c > @@ -1994,7 +1994,7 @@ static int pid_revalidate(struct dentry *dentry, > unsigned int flags) > > static inline bool proc_inode_is_dead(struct inode *inode) > { > - return !proc_pid(inode)->tasks[PIDTYPE_PID].first; > + return !get_proc_task(inode); > } > > int pid_delete_dentry(const struct dentry *dentry) > -- > 2.25.1 >
