diff options
| author | Thomas Pugliese <thomas.pugliese@gmail.com> | 2014-03-04 21:24:55 +0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-03-08 00:39:39 +0400 |
| commit | 2a6da97ff530650d26570a6a1ec0ac1deac927bd (patch) | |
| tree | 64222edab88045ceda239c12a719fbcafd4889db /drivers/usb | |
| parent | 3c1b2c3ecd3122fe6dded7b012f74021144d95b2 (diff) | |
| download | linux-2a6da97ff530650d26570a6a1ec0ac1deac927bd.tar.xz | |
usb: wusbcore: fix potential double list_del on urb dequeue
This patch locks rpipe->seg_lock around the entire transfer segment
cleanup loop in wa_urb_dequeue instead of just one case of the switch
statement. This fixes a race between __wa_xfer_delayed_run and
wa_urb_dequeue where a transfer segment in the WA_SEG_DELAYED state
could be removed from the rpipe seg_list twice leading to memory
corruption. It also switches the spin_lock call to use the non-irqsave
version since the xfer->lock is already held and irqs already disabled.
Signed-off-by: Thomas Pugliese <thomas.pugliese@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb')
| -rw-r--r-- | drivers/usb/wusbcore/wa-xfer.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/drivers/usb/wusbcore/wa-xfer.c b/drivers/usb/wusbcore/wa-xfer.c index 404ce81b286c..6e0d377d437c 100644 --- a/drivers/usb/wusbcore/wa-xfer.c +++ b/drivers/usb/wusbcore/wa-xfer.c @@ -1974,6 +1974,11 @@ int wa_urb_dequeue(struct wahc *wa, struct urb *urb, int status) goto out_unlock; /* setup(), enqueue_b() completes */ /* Ok, the xfer is in flight already, it's been setup and submitted.*/ xfer_abort_pending = __wa_xfer_abort(xfer) >= 0; + /* + * grab the rpipe->seg_lock here to prevent racing with + * __wa_xfer_delayed_run. + */ + spin_lock(&rpipe->seg_lock); for (cnt = 0; cnt < xfer->segs; cnt++) { seg = xfer->seg[cnt]; pr_debug("%s: xfer id 0x%08X#%d status = %d\n", @@ -1994,10 +1999,8 @@ int wa_urb_dequeue(struct wahc *wa, struct urb *urb, int status) */ seg->status = WA_SEG_ABORTED; seg->result = -ENOENT; - spin_lock_irqsave(&rpipe->seg_lock, flags2); list_del(&seg->list_node); xfer->segs_done++; - spin_unlock_irqrestore(&rpipe->seg_lock, flags2); break; case WA_SEG_DONE: case WA_SEG_ERROR: @@ -2026,6 +2029,7 @@ int wa_urb_dequeue(struct wahc *wa, struct urb *urb, int status) break; } } + spin_unlock(&rpipe->seg_lock); xfer->result = urb->status; /* -ENOENT or -ECONNRESET */ done = __wa_xfer_is_done(xfer); spin_unlock_irqrestore(&xfer->lock, flags); |