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libpayload: usbmsc: Prevent usbdisk_remove() from being called twice

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When removing SD card from USB card reader, the USB MSC stack does
not detach the device immediately. Instead, the USB MSC stack calls
usbdisk_remove() and calls usb_msc_destroy() after several pollings.
It results in usbdisk_remove() being called twice.

Since the usbmsc_inst_t instance is freed after first usbdisk_remove()
call, the second call invokes an invalid usbmsc_inst_t instance and
causes exception in CPU.

This patch prevents usbdisk_remove() from being called twice by setting
usbdisk_created to zero.

BUG=b:239492347
TEST=insert an empty SD card into the USB card reader then remove
     the SD card. AP firmware does not crash.

Change-Id: I0675e9fde3e770d63dd0047928356a204245ef18
Signed-off-by: Yidi Lin <yidilin@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/66449
Reviewed-by: Yu-Ping Wu <yupingso@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
This commit is contained in:
Yidi Lin 2022-08-05 15:40:48 +08:00 • committed by Martin Roth
commit 8610dd5022
1 changed files with 3 additions and 1 deletions
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4
payloads/libpayload/drivers/usb/usbmsc.c
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@ -78,8 +78,10 @@ usb_msc_create_disk (usbdev_t *dev)
static void
usb_msc_remove_disk (usbdev_t *dev)
{
if (MSC_INST (dev)->usbdisk_created && usbdisk_remove)
if (MSC_INST (dev)->usbdisk_created && usbdisk_remove) {
usbdisk_remove (dev);
MSC_INST (dev)->usbdisk_created = 0;
}
}
static void