From: Yonghong Song <[email protected]>

[ Upstream commit e60572b8d4c39572be6857d1ec91fdf979f8775f ]

Currently when traversing all tasks, the next tid
is always increased by one. This may result in
visiting the same task multiple times in a
pid namespace.

This patch fixed the issue by seting the next
tid as pid_nr_ns(pid, ns) + 1, similar to
funciton next_tgid().

Signed-off-by: Yonghong Song <[email protected]>
Signed-off-by: Alexei Starovoitov <[email protected]>
Cc: Rik van Riel <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]
Signed-off-by: Sasha Levin <[email protected]>
---
 kernel/bpf/task_iter.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/kernel/bpf/task_iter.c b/kernel/bpf/task_iter.c
index ac7869a389990..cd7d9564bcef6 100644
--- a/kernel/bpf/task_iter.c
+++ b/kernel/bpf/task_iter.c
@@ -28,8 +28,9 @@ static struct task_struct *task_seq_get_next(struct 
pid_namespace *ns,
 
        rcu_read_lock();
 retry:
-       pid = idr_get_next(&ns->idr, tid);
+       pid = find_ge_pid(*tid, ns);
        if (pid) {
+               *tid = pid_nr_ns(pid, ns);
                task = get_pid_task(pid, PIDTYPE_PID);
                if (!task) {
                        ++*tid;
-- 
2.25.1

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