diff options
| author | Ming Lei <tom.leiming@gmail.com> | 2012-04-26 11:33:46 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-05-21 09:40:01 -0700 |
| commit | 5b05ac638c39e92f3fa6291b4aebd6fc485320ba (patch) | |
| tree | a1e7c81afad8a72033e2393468fc00091003a864 /include | |
| parent | b147567a79744253aa13c8266bfc48ceb70eff6c (diff) | |
usbnet: fix skb traversing races during unlink(v2)
commit 5b6e9bcdeb65634b4ad604eb4536404bbfc62cfa upstream.
Commit 4231d47e6fe69f061f96c98c30eaf9fb4c14b96d(net/usbnet: avoid
recursive locking in usbnet_stop()) fixes the recursive locking
problem by releasing the skb queue lock before unlink, but may
cause skb traversing races:
- after URB is unlinked and the queue lock is released,
the refered skb and skb->next may be moved to done queue,
even be released
- in skb_queue_walk_safe, the next skb is still obtained
by next pointer of the last skb
- so maybe trigger oops or other problems
This patch extends the usage of entry->state to describe 'start_unlink'
state, so always holding the queue(rx/tx) lock to change the state if
the referd skb is in rx or tx queue because we need to know if the
refered urb has been started unlinking in unlink_urbs.
The other part of this patch is based on Huajun's patch:
always traverse from head of the tx/rx queue to get skb which is
to be unlinked but not been started unlinking.
Signed-off-by: Huajun Li <huajun.li.lee@gmail.com>
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Cc: Oliver Neukum <oneukum@suse.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/usb/usbnet.h | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/include/linux/usb/usbnet.h b/include/linux/usb/usbnet.h index 605b0aa8d85..76f439647c4 100644 --- a/include/linux/usb/usbnet.h +++ b/include/linux/usb/usbnet.h @@ -191,7 +191,8 @@ extern void usbnet_cdc_status(struct usbnet *, struct urb *); enum skb_state { illegal = 0, tx_start, tx_done, - rx_start, rx_done, rx_cleanup + rx_start, rx_done, rx_cleanup, + unlink_start }; struct skb_data { /* skb->cb is one of these */ |