From: Jens Axboe axboe@kernel.dk
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@vger.kernel.org Fixes: 8d4c3e76e3be ("proc: don't allow async path resolution of /proc/self components") Reported-by: Eric W. Biederman ebiederm@xmission.com Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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);