Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 16c4cb19 authored by Harry Pan's avatar Harry Pan Committed by Greg Kroah-Hartman
Browse files

usb: core: safely deal with the dynamic quirk lists 



Applying dynamic usbcore quirks in early booting when the slab is
not yet ready would cause kernel panic of null pointer dereference
because the quirk_count has been counted as 1 while the quirk_list
was failed to allocate.

i.e.,
[    1.044970] BUG: unable to handle kernel NULL pointer dereference at           (null)
[    1.044995] IP: [<ffffffffb0953ec7>] usb_detect_quirks+0x88/0xd1
[    1.045016] PGD 0
[    1.045026] Oops: 0000 [#1] PREEMPT SMP
[    1.046986] gsmi: Log Shutdown Reason 0x03
[    1.046995] Modules linked in:
[    1.047008] CPU: 0 PID: 81 Comm: kworker/0:3 Not tainted 4.4.154 #28
[    1.047016] Hardware name: Google Coral/Coral, BIOS Google_Coral.10068.27.0 12/04/2017
[    1.047028] Workqueue: usb_hub_wq hub_event
[    1.047037] task: ffff88017a321c80 task.stack: ffff88017a384000
[    1.047044] RIP: 0010:[<ffffffffb0953ec7>]  [<ffffffffb0953ec7>] usb_detect_quirks+0x88/0xd1

To tackle this odd, let's balance the quirk_count to 0 when the kcalloc
call fails, and defer the quirk setting into a lower level callback
which ensures that the kernel memory management has been initialized.

Fixes: 027bd6ca ("usb: core: Add "quirks" parameter for usbcore")
Signed-off-by: default avatarHarry Pan <harry.pan@intel.com>
Acked-by: default avatarKai-Heng Feng <kai.heng.feng@canonical.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 5c54fcac

drivers/usb/core/quirks.c

+2 −1
Original line number Diff line number Diff line
@@ -58,6 +58,7 @@ static int quirks_param_set(const char *val, const struct kernel_param *kp) 
	quirk_list = kcalloc(quirk_count, sizeof(struct quirk_entry),

			     GFP_KERNEL);

	if (!quirk_list) {

		quirk_count = 0;

		mutex_unlock(&quirk_mutex);

		return -ENOMEM;

	}
@@ -154,7 +155,7 @@ static struct kparam_string quirks_param_string = { 
	.string = quirks_param,

};



module_param_cb(quirks, &quirks_param_ops, &quirks_param_string, 0644);

device_param_cb(quirks, &quirks_param_ops, &quirks_param_string, 0644);

MODULE_PARM_DESC(quirks, "Add/modify USB quirks by specifying quirks=vendorID:productID:quirks");



/* Lists of quirky USB devices, split in device quirks and interface quirks.