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| author | Andrea Righi <arighi@develer.com> | 2010-06-28 16:56:45 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2010-08-10 23:35:38 +0200 |
| commit | 4307a28eb0128417d9a2b9d858d2bce70ee5b383 (patch) | |
| tree | 46efab423c646ba4a994533b1e5befe523fbf08a /drivers/usb/host/ehci-hcd.c | |
| parent | USB: xhci: trivial: use ARRAY_SIZE (diff) | |
| download | linux-4307a28eb0128417d9a2b9d858d2bce70ee5b383.tar.xz linux-4307a28eb0128417d9a2b9d858d2bce70ee5b383.zip | |
USB: EHCI: fix NULL pointer dererence in HCDs that use HCD_LOCAL_MEM
If we use the HCD_LOCAL_MEM flag and dma_declare_coherent_memory() to
enforce the host controller's local memory utilization we also need to
disable native scatter-gather support, otherwise hcd_alloc_coherent() in
map_urb_for_dma() is called with urb->transfer_buffer == NULL, that
triggers a NULL pointer dereference.
We can also consider to add a WARN_ON() and return an error code to
better catch this problem in the future.
At the moment no driver seems to hit this bug, so I should
consider this a low-priority fix.
Signed-off-by: Andrea Righi <arighi@develer.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/usb/host/ehci-hcd.c')
| -rw-r--r-- | drivers/usb/host/ehci-hcd.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c index 2a19336c9824..2e704fa3cedf 100644 --- a/drivers/usb/host/ehci-hcd.c +++ b/drivers/usb/host/ehci-hcd.c @@ -629,7 +629,8 @@ static int ehci_init(struct usb_hcd *hcd) ehci->command = temp; /* Accept arbitrarily long scatter-gather lists */ - hcd->self.sg_tablesize = ~0; + if (!(hcd->driver->flags & HCD_LOCAL_MEM)) + hcd->self.sg_tablesize = ~0; return 0; } |