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authorDu, Changbin <changbin.du@intel.com>2016-01-18 21:02:42 +0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-02-19 14:28:33 -0800
commit9932571e08f36fdb83d8a29de5a6b6aeae6dbfb8 (patch)
tree1bd7dba9ca90303baac449c550eb151cbab5eb0f
parent52827582844e0a6b951875e64d799e68ed4cceb7 (diff)
usb: hub: do not clear BOS field during reset device
commit d8f00cd685f5c8e0def8593e520a7fef12c22407 upstream. In function usb_reset_and_verify_device, the old BOS descriptor may still be used before allocating a new one. (usb_unlocked_disable_lpm function uses it under the situation that it fails to disable lpm.) So we cannot set the udev->bos to NULL before that, just keep what it was. It will be overwrite when allocating a new one. Crash log: BUG: unable to handle kernel NULL pointer dereference at 0000000000000010 IP: [<ffffffff8171f98d>] usb_enable_link_state+0x2d/0x2f0 Call Trace: [<ffffffff8171ed5b>] ? usb_set_lpm_timeout+0x12b/0x140 [<ffffffff8171fcd1>] usb_enable_lpm+0x81/0xa0 [<ffffffff8171fdd8>] usb_disable_lpm+0xa8/0xc0 [<ffffffff8171fe1c>] usb_unlocked_disable_lpm+0x2c/0x50 [<ffffffff81723933>] usb_reset_and_verify_device+0xc3/0x710 [<ffffffff8172c4ed>] ? usb_sg_wait+0x13d/0x190 [<ffffffff81724743>] usb_reset_device+0x133/0x280 [<ffffffff8179ccd1>] usb_stor_port_reset+0x61/0x70 [<ffffffff8179cd68>] usb_stor_invoke_transport+0x88/0x520 Signed-off-by: Du, Changbin <changbin.du@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/usb/core/hub.c8
1 files changed, 5 insertions, 3 deletions
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 62084335a608..a2fef797d553 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -5377,7 +5377,6 @@ static int usb_reset_and_verify_device(struct usb_device *udev)
}
bos = udev->bos;
- udev->bos = NULL;
for (i = 0; i < SET_CONFIG_TRIES; ++i) {
@@ -5470,8 +5469,11 @@ done:
usb_set_usb2_hardware_lpm(udev, 1);
usb_unlocked_enable_lpm(udev);
usb_enable_ltm(udev);
- usb_release_bos_descriptor(udev);
- udev->bos = bos;
+ /* release the new BOS descriptor allocated by hub_port_init() */
+ if (udev->bos != bos) {
+ usb_release_bos_descriptor(udev);
+ udev->bos = bos;
+ }
return 0;
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