From: "Du, Changbin" <changbin.du@xxxxxxxxx>
This is a reworked patch based on reverted commit d8f00cd685f5 ("usb:
hub: do not clear BOS field during reset device").
The privious one caused double mem-free if run to re_enumerate label.
New patch title changed to distinguish from old one. And I have tested
it with memory debugging options.
In function usb_reset_and_verify_device, the old BOS descriptor may
still be used before allocating a new one. (usb_disable_lpm function
uses it under the situation that it fails at usb_disable_link_state.)
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.
How to reproduce:
1. connect one usb3 hub to xhci port.
2. connect several lpm-capable super-speed usb disk to the hub.
3. copy big files to the usb disks.
4. disconnect the hub and repeat step 1-4.
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@xxxxxxxxx>
---
drivers/usb/core/hub.c | 14 +++++++++-----
1 file changed, 9 insertions(+), 5 deletions(-)
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 51b43691..27444e5 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -5401,7 +5401,6 @@ 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) {
@@ -5494,13 +5493,18 @@ 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;
re_enumerate:
- usb_release_bos_descriptor(udev);
- udev->bos = bos;
+ if (udev->bos != bos) {
+ usb_release_bos_descriptor(udev);
+ udev->bos = bos;
+ }
re_enumerate_no_bos:
/* LPM state doesn't matter when we're about to destroy the device. */
hub_port_logical_disconnect(parent_hub, port1);
--
2.5.0
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