Re: [PATCH] cifs: fix panic in smb2_reconnect

вт, 4 июн. 2019 г. в 17:16, Ronnie Sahlberg lsahlber@redhat.com:

RH Bugzilla: 1702264

We need to protect so that the call to smb2_reconnect() in smb2_reconnect_server() does not end up freeing the session because it can lead to a use after free and crash.

Reviewed-by: Aurelien Aptel aaptel@suse.com Cc: stable@vger.kernel.org Signed-off-by: Ronnie Sahlberg lsahlber@redhat.com

---

fs/cifs/smb2pdu.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c index 565b60b62f4d..ab8dc73d2282 100644 --- a/fs/cifs/smb2pdu.c +++ b/fs/cifs/smb2pdu.c @@ -3113,9 +3113,14 @@ void smb2_reconnect_server(struct work_struct *work) tcon_exist = true; } }

•           /*
  

•            * IPC has the same lifetime as its session and uses its
  

•            * refcount.
  

•            */
            if (ses->tcon_ipc && ses->tcon_ipc->need_reconnect) {
                    list_add_tail(&ses->tcon_ipc->rlist, &tmp_list);
                    tcon_exist = true;
  

•                   ses->ses_count++;
            }
    }
    /*
  

@@ -3134,7 +3139,10 @@ void smb2_reconnect_server(struct work_struct *work) else resched = true; list_del_init(&tcon->rlist);

•           cifs_put_tcon(tcon);
  

•           if (tcon->ipc)
  

•                   cifs_put_smb_ses(tcon->ses);
  

•           else
  

•                   cifs_put_tcon(tcon);
    }
  
    cifs_dbg(FYI, "Reconnecting tcons finished\n");
  

-- 2.13.6

Reviewed-by: Pavel Shilovsky pshilov@microsoft.com

-- Best regards, Pavel Shilovsky