diff options
| author | Jinliang Zheng <alexjlzheng@tencent.com> | 2026-01-28 16:30:07 +0800 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2026-02-08 00:13:34 -0800 |
| commit | 76149d53502cf17ef3ae454ff384551236fba867 (patch) | |
| tree | 5cc2da12a118c8794f2327cf5af02d8e4555f3fb | |
| parent | cafe4074a7221dca2fa954dd1ab0cf99b6318e23 (diff) | |
procfs: fix missing RCU protection when reading real_parent in do_task_stat()
When reading /proc/[pid]/stat, do_task_stat() accesses task->real_parent
without proper RCU protection, which leads to:
cpu 0 cpu 1
----- -----
do_task_stat
var = task->real_parent
release_task
call_rcu(delayed_put_task_struct)
task_tgid_nr_ns(var)
rcu_read_lock <--- Too late to protect task->real_parent!
task_pid_ptr <--- UAF!
rcu_read_unlock
This patch uses task_ppid_nr_ns() instead of task_tgid_nr_ns() to add
proper RCU protection for accessing task->real_parent.
Link: https://lkml.kernel.org/r/20260128083007.3173016-1-alexjlzheng@tencent.com
Fixes: 06fffb1267c9 ("do_task_stat: don't take rcu_read_lock()")
Signed-off-by: Jinliang Zheng <alexjlzheng@tencent.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Mateusz Guzik <mjguzik@gmail.com>
Cc: ruippan <ruippan@tencent.com>
Cc: Usama Arif <usamaarif642@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| -rw-r--r-- | fs/proc/array.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/proc/array.c b/fs/proc/array.c index 39e9246f6e4a..f447e734612a 100644 --- a/fs/proc/array.c +++ b/fs/proc/array.c @@ -529,7 +529,7 @@ static int do_task_stat(struct seq_file *m, struct pid_namespace *ns, } sid = task_session_nr_ns(task, ns); - ppid = task_tgid_nr_ns(task->real_parent, ns); + ppid = task_ppid_nr_ns(task, ns); pgid = task_pgrp_nr_ns(task, ns); unlock_task_sighand(task, &flags); |