Return-Path: Date: Mon, 29 Sep 2008 23:47:52 +0530 From: Rabin Vincent To: Justin Mattock Cc: Linux Kernel Mailing List , marcel@holtmann.org, linux-bluetooth@vger.kernel.org Subject: Re: BUG kmalloc-16: Object already free Message-ID: <20080929181752.GA2027@debian> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: Sender: Rabin Vincent List-ID: On Sun, Sep 28, 2008 at 03:54:23PM -0700, Justin Mattock wrote: > After frying my system, I'm finally up and > running. Not sure if this was due to a git-pull > (only be a few days since the last pull), or what: > when waking from suspend I see this > (I know it says tainted in it, so this will be the only noise you'll > here from me on this); > > [ 274.327003] ============================================================================= > [ 274.327528] BUG kmalloc-16: Object already free > [ 274.327877] ----------------------------------------------------------------------------- > [ 274.327879] > [ 274.327890] INFO: Allocated in btusb_open+0x82/0x16f [btusb] age=0 > cpu=1 pid=3763 > [ 274.327899] INFO: Freed in btusb_open+0x13d/0x16f [btusb] age=0 > cpu=1 pid=3763 > [ 274.327905] INFO: Slab 0xc139a100 objects=64 used=62 fp=0xdcd08100 > flags=0x400000c3 There's a commit in the latest git which looks like it will solve the btusb suspend/resume issues: 5fbcd260.. ("[Bluetooth] Fix USB disconnect handling of btusb driver"). Marcel / linux-bluetooth, I think this double free is a separate issue with the error handling, and the following patch should fix it. --- From: Rabin Vincent Subject: [PATCH] btusb, bpa10x: fix double frees on error paths Justin Mattock reported this double free in btusb: BUG kmalloc-16: Object already free ----------------------------------------------------------------------------- INFO: Allocated in btusb_open+0x82/0x16f [btusb] age=3D0 cpu=3D1 pid=3D3763 INFO: Freed in btusb_open+0x13d/0x16f [btusb] age=3D0 cpu=3D1 pid=3D3763 This occurs because the urb's transfer buffer is being freed separately in the error path even though the URB_FREE_BUFFER transfer_flag is set on the urb. There are similar cases elsewhere in btusb and in bpa10x. Fix all of them by removing the additional kfree()'s. Reported-by: Justin Mattock Signed-off-by: Rabin Vincent --- drivers/bluetooth/bpa10x.c | 2 -- drivers/bluetooth/btusb.c | 3 --- 2 files changed, 0 insertions(+), 5 deletions(-) diff --git a/drivers/bluetooth/bpa10x.c b/drivers/bluetooth/bpa10x.c index 1e55a65..32f3a8e 100644 --- a/drivers/bluetooth/bpa10x.c +++ b/drivers/bluetooth/bpa10x.c @@ -256,7 +256,6 @@ static inline int bpa10x_submit_intr_urb(struct hci_dev *hdev) BT_ERR("%s urb %p submission failed (%d)", hdev->name, urb, -err); usb_unanchor_urb(urb); - kfree(buf); } usb_free_urb(urb); @@ -298,7 +297,6 @@ static inline int bpa10x_submit_bulk_urb(struct hci_dev *hdev) BT_ERR("%s urb %p submission failed (%d)", hdev->name, urb, -err); usb_unanchor_urb(urb); - kfree(buf); } usb_free_urb(urb); diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c index 29ae998..262e9be 100644 --- a/drivers/bluetooth/btusb.c +++ b/drivers/bluetooth/btusb.c @@ -271,7 +271,6 @@ static int btusb_submit_intr_urb(struct hci_dev *hdev) BT_ERR("%s urb %p submission failed (%d)", hdev->name, urb, -err); usb_unanchor_urb(urb); - kfree(buf); } usb_free_urb(urb); @@ -354,7 +353,6 @@ static int btusb_submit_bulk_urb(struct hci_dev *hdev) BT_ERR("%s urb %p submission failed (%d)", hdev->name, urb, -err); usb_unanchor_urb(urb); - kfree(buf); } usb_free_urb(urb); @@ -475,7 +473,6 @@ static int btusb_submit_isoc_urb(struct hci_dev *hdev) BT_ERR("%s urb %p submission failed (%d)", hdev->name, urb, -err); usb_unanchor_urb(urb); - kfree(buf); } usb_free_urb(urb); -- 1.5.6.5