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authorAndrea Righi <arighi@develer.com>2010-06-28 16:56:45 +0200
committerGreg Kroah-Hartman <gregkh@suse.de>2010-08-10 14:35:38 -0700
commit4307a28eb0128417d9a2b9d858d2bce70ee5b383 (patch)
tree46efab423c646ba4a994533b1e5befe523fbf08a /drivers/usb/host
parente10fa4787f1fb9c8738dff955c272f30b7b63134 (diff)
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')
-rw-r--r--drivers/usb/host/ehci-hcd.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
index 2a19336c982..2e704fa3ced 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;
}