From: Jens Axboe <axboe@xxxxxxxxx>
commit 0d4370cfe36b7f1719123b621a4ec4d9c7a25f89 upstream.
If this is attempted by an io-wq kthread, then return -EOPNOTSUPP as we
don't currently support that. Once we can get task_pid_ptr() doing the
right thing, then this can go away again.
Use PF_IO_WORKER for this to speciically target the io_uring workers.
Modify the /proc/self/ check to use PF_IO_WORKER as well.
Cc: stable@xxxxxxxxxxxxxxx
Fixes: 8d4c3e76e3be ("proc: don't allow async path resolution of /proc/self components")
Reported-by: Eric W. Biederman <ebiederm@xxxxxxxxxxxx>
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/proc/self.c | 2 +-
fs/proc/thread_self.c | 7 +++++++
2 files changed, 8 insertions(+), 1 deletion(-)
--- a/fs/proc/self.c
+++ b/fs/proc/self.c
@@ -20,7 +20,7 @@ static const char *proc_self_get_link(st
* Not currently supported. Once we can inherit all of struct pid,
* we can allow this.
*/
- if (current->flags & PF_KTHREAD)
+ if (current->flags & PF_IO_WORKER)
return ERR_PTR(-EOPNOTSUPP);
if (!tgid)
--- a/fs/proc/thread_self.c
+++ b/fs/proc/thread_self.c
@@ -17,6 +17,13 @@ static const char *proc_thread_self_get_
pid_t pid = task_pid_nr_ns(current, ns);
char *name;
+ /*
+ * Not currently supported. Once we can inherit all of struct pid,
+ * we can allow this.
+ */
+ if (current->flags & PF_IO_WORKER)
+ return ERR_PTR(-EOPNOTSUPP);
+
if (!pid)
return ERR_PTR(-ENOENT);
name = kmalloc(10 + 6 + 10 + 1, dentry ? GFP_KERNEL : GFP_ATOMIC);
