| Message ID | 1455920722-20892-1-git-send-email-dianders@chromium.org |
|---|---|
| State | Awaiting Upstream, archived |
| Delegated to: | David Miller |
| Headers | show |
Hi Douglas, On Fri, Feb 19, 2016, Douglas Anderson wrote: > In commit 44d271377479 ("Bluetooth: Compress the size of struct > hci_ctrl") we squashed down the size of the structure by using a union > with the assumption that all users would use the flag to determine > whether we had a req_complete or a req_complete_skb. > > Unfortunately we had a case in hci_req_cmd_complete() where we weren't > looking at the flag. This can result in a situation where we might be > storing a hci_req_complete_skb_t in a hci_req_complete_t variable, or > vice versa. > > During some testing I found at least one case where the function > hci_req_sync_complete() was called improperly because the kernel thought > that it didn't require an SKB. Looking through the stack in kgdb I > found that it was called by hci_event_packet() and that > hci_event_packet() had both of its locals "req_complete" and > "req_complete_skb" pointing to the same place: both to > hci_req_sync_complete(). > > Let's make sure we always check the flag. > > For more details on debugging done, see <http://crbug.com/588288>. > > Fixes: 44d271377479 ("Bluetooth: Compress the size of struct hci_ctrl") > Signed-off-by: Douglas Anderson <dianders@chromium.org> > --- > Testing was done on a Chrome OS device on kernel 3.14 w/ > bluetooth-next backports. Since I couldn't reliably reproduce the > problem, I simply confirmed that existing functionality worked. > > net/bluetooth/hci_core.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) Good catch. Acked-by: Johan Hedberg <johan.hedberg@intel.com> Marcel, I think we want to send this through our stable tree to 4.5-rc (where the patch introducing the bug is). Johan
Hi Douglas, > In commit 44d271377479 ("Bluetooth: Compress the size of struct > hci_ctrl") we squashed down the size of the structure by using a union > with the assumption that all users would use the flag to determine > whether we had a req_complete or a req_complete_skb. > > Unfortunately we had a case in hci_req_cmd_complete() where we weren't > looking at the flag. This can result in a situation where we might be > storing a hci_req_complete_skb_t in a hci_req_complete_t variable, or > vice versa. > > During some testing I found at least one case where the function > hci_req_sync_complete() was called improperly because the kernel thought > that it didn't require an SKB. Looking through the stack in kgdb I > found that it was called by hci_event_packet() and that > hci_event_packet() had both of its locals "req_complete" and > "req_complete_skb" pointing to the same place: both to > hci_req_sync_complete(). > > Let's make sure we always check the flag. > > For more details on debugging done, see <http://crbug.com/588288>. > > Fixes: 44d271377479 ("Bluetooth: Compress the size of struct hci_ctrl") > Signed-off-by: Douglas Anderson <dianders@chromium.org> > --- > Testing was done on a Chrome OS device on kernel 3.14 w/ > bluetooth-next backports. Since I couldn't reliably reproduce the > problem, I simply confirmed that existing functionality worked. > > net/bluetooth/hci_core.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) patch has been applied to bluetooth-stable tree. Regards Marcel
diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c index 541760fe53d4..9c0a6830ff92 100644 --- a/net/bluetooth/hci_core.c +++ b/net/bluetooth/hci_core.c @@ -4118,8 +4118,10 @@ void hci_req_cmd_complete(struct hci_dev *hdev, u16 opcode, u8 status, break; } - *req_complete = bt_cb(skb)->hci.req_complete; - *req_complete_skb = bt_cb(skb)->hci.req_complete_skb; + if (bt_cb(skb)->hci.req_flags & HCI_REQ_SKB) + *req_complete_skb = bt_cb(skb)->hci.req_complete_skb; + else + *req_complete = bt_cb(skb)->hci.req_complete; kfree_skb(skb); } spin_unlock_irqrestore(&hdev->cmd_q.lock, flags);
In commit 44d271377479 ("Bluetooth: Compress the size of struct hci_ctrl") we squashed down the size of the structure by using a union with the assumption that all users would use the flag to determine whether we had a req_complete or a req_complete_skb. Unfortunately we had a case in hci_req_cmd_complete() where we weren't looking at the flag. This can result in a situation where we might be storing a hci_req_complete_skb_t in a hci_req_complete_t variable, or vice versa. During some testing I found at least one case where the function hci_req_sync_complete() was called improperly because the kernel thought that it didn't require an SKB. Looking through the stack in kgdb I found that it was called by hci_event_packet() and that hci_event_packet() had both of its locals "req_complete" and "req_complete_skb" pointing to the same place: both to hci_req_sync_complete(). Let's make sure we always check the flag. For more details on debugging done, see <http://crbug.com/588288>. Fixes: 44d271377479 ("Bluetooth: Compress the size of struct hci_ctrl") Signed-off-by: Douglas Anderson <dianders@chromium.org> --- Testing was done on a Chrome OS device on kernel 3.14 w/ bluetooth-next backports. Since I couldn't reliably reproduce the problem, I simply confirmed that existing functionality worked. net/bluetooth/hci_core.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)