CVE-2024-26748

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. Neednt call usb_gadget_giveback_request() because it is allocated in this driver.

Weakness

The product calls free() twice on the same memory address, potentially leading to modification of unexpected memory locations.

Affected Software

Potential Mitigations

References

• https://git.kernel.org/stable/c/1e204a8e9eb514e22a6567fb340ebb47df3f3a48
• https://git.kernel.org/stable/c/3a2a909942b5335b7ea66366d84261b3ed5f89c8
• https://git.kernel.org/stable/c/5fd9e45f1ebcd57181358af28506e8a661a260b3
• https://git.kernel.org/stable/c/70e8038813f9d3e72df966748ebbc40efe466019
• https://git.kernel.org/stable/c/92d20406a3d4ff3e8be667c79209dc9ed31df5b3
• https://git.kernel.org/stable/c/9a52b694b066f299d8b9800854a8503457a8b64c
• https://git.kernel.org/stable/c/aad6132ae6e4809e375431f8defd1521985e44e7
• https://git.kernel.org/stable/c/1e204a8e9eb514e22a6567fb340ebb47df3f3a48
• https://git.kernel.org/stable/c/3a2a909942b5335b7ea66366d84261b3ed5f89c8
• https://git.kernel.org/stable/c/5fd9e45f1ebcd57181358af28506e8a661a260b3
• https://git.kernel.org/stable/c/70e8038813f9d3e72df966748ebbc40efe466019
• https://git.kernel.org/stable/c/92d20406a3d4ff3e8be667c79209dc9ed31df5b3
• https://git.kernel.org/stable/c/9a52b694b066f299d8b9800854a8503457a8b64c
• https://git.kernel.org/stable/c/aad6132ae6e4809e375431f8defd1521985e44e7
• https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html