[SRU][M/J][PATCH 0/1] CVE-2024-26748

[Bethany Jamison]

[Impact]

 In the Linux kernel, the following vulnerability has been resolved:

 usb: cdns3: fix memory double free when handle zero packet

 829  if (request->complete) {
 830          spin_unlock(&priv_dev->lock);
 831          usb_gadget_giveback_request(&priv_ep->endpoint,
 832                                    request);
 833          spin_lock(&priv_dev->lock);
 834  }
 835
 836  if (request->buf == priv_dev->zlp_buf)
 837      cdns3_gadget_ep_free_request(&priv_ep->endpoint, request);

 Driver append an additional zero packet request when queue a packet, which
 length mod max packet size is 0. When transfer complete, run to line 831,
 usb_gadget_giveback_request() will free this requestion. 836 condition is
 true, so cdns3_gadget_ep_free_request() free this request again.

 Log:

 [ 1920.140696][  T150] BUG: KFENCE: use-after-free read in
 cdns3_gadget_giveback+0x134/0x2c0 [cdns3]
 [ 1920.140696][  T150]
 [ 1920.151837][  T150] Use-after-free read at 0x000000003d1cd10b (in
 kfence-#36):
 [ 1920.159082][  T150]  cdns3_gadget_giveback+0x134/0x2c0 [cdns3]
 [ 1920.164988][  T150]  cdns3_transfer_completed+0x438/0x5f8 [cdns3]

 Add check at line 829, skip call usb_gadget_giveback_request() if it is
 additional zero length packet request. Needn't call
 usb_gadget_giveback_request() because it is allocated in this driver.

[Fix]

Mantic:	Clean cherry-pick.
Jammy:	Mantic patch applied cleanly.
Focal:	fix in stable
Bionic:	not-affected
Xenial:	not-affected
Trusty:	not-affected

[Test Case]

Compile and boot tested.

[Where problems could occur]

This fix affects those who use CDNS3 (a SuperSpeed (SS) USB 3.0 
Dual-Role-Device (DRD) controller from Cadence), an issue with this fix
would be visable via a memory leak or a system crash.

Frank Li (1):
  usb: cdns3: fix memory double free when handle zero packet

 drivers/usb/cdns3/cdns3-gadget.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

-- 
2.34.1