[PATCH] procfs: Do not list TID 0 in /proc/<pid>/task

From: Florian Weimer
Date: Wed Sep 29 2021 - 16:23:42 EST


If a task exits concurrently, task_pid_nr_ns may return 0.

Signed-off-by: Florian Weimer <fweimer@xxxxxxxxxx>
---
fs/proc/base.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/fs/proc/base.c b/fs/proc/base.c
index 533d5836eb9a..54f29399088f 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -3800,6 +3800,9 @@ static int proc_task_readdir(struct file *file, struct dir_context *ctx)
char name[10 + 1];
unsigned int len;
tid = task_pid_nr_ns(task, ns);
+ if (!tid)
+ /* The task has just exited. */
+ continue;
len = snprintf(name, sizeof(name), "%u", tid);
if (!proc_fill_cache(file, ctx, name, len,
proc_task_instantiate, task, NULL)) {
--
2.31.1