Re: [PATCH] ksmbd: fix possible memory leak in smb2_lock()

[Hangyu Hua]

On 4/2/2023 18:10, Namjae Jeon wrote:
> 2023-02-01 17:10 GMT+09:00, Hangyu Hua <hbh25y@xxxxxxxxx>:
> > argv needs to be free when setup_async_work fails or when the current
> > process is woken up.
> >
> > Fixes: e2f34481b24d ("cifsd: add server-side procedures for SMB3")
> > Signed-off-by: Hangyu Hua <hbh25y@xxxxxxxxx>
> > ---
> >   fs/ksmbd/smb2pdu.c | 3 +++
> >   1 file changed, 3 insertions(+)
> >
> > diff --git a/fs/ksmbd/smb2pdu.c b/fs/ksmbd/smb2pdu.c
> > index d681f91947d9..5b7668c04f76 100644
> > --- a/fs/ksmbd/smb2pdu.c
> > +++ b/fs/ksmbd/smb2pdu.c
> > @@ -7050,6 +7050,7 @@ int smb2_lock(struct ksmbd_work *work)
> >   						      smb2_remove_blocked_lock,
> >   						      argv);
> >   				if (rc) {
> > +					kfree(argv);
> >   					err = -ENOMEM;
> >   					goto out;
> >   				}
> > @@ -7061,6 +7062,8 @@ int smb2_lock(struct ksmbd_work *work)
> >
> >   				ksmbd_vfs_posix_lock_wait(flock);
> >
> > +				work->cancel_fn = NULL;
> > +				kfree(argv);
> This change seems to causes a NULL pointer dereference issue in
> set_close_state_blocked_works(). It is right to free it and set NULL
> after removing entry from list.

I get it. I will send a v2.

Thanks,
Hangyu
> >   				if (work->state != KSMBD_WORK_ACTIVE) {
> >   					list_del(&smb_lock->llist);
> >   					spin_lock(&work->conn->llist_lock);
> > --
> > 2.34.1