CVE-2024-27066 Information

Description

In the Linux kernel the following vulnerability has been resolved:

virtio: packed: fix unmap leak for indirect desc table

When use_dma_api and premapped are true then the do_unmap is false.

Because the do_unmap is false vring_unmap_extra_packed is not called by detach_buf_packed.

if (unlikely(vq->do_unmap)) curr = id; for (i = 0; i < state->num; i++) vring_unmap_extra_packed(vq &vq->packed.desc_extra[curr]); curr = vq->packed.desc_extra[curr].next;

So the indirect desc table is not unmapped. This causes the unmap leak.

So here we check vq->use_dma_api instead. Synchronously dma info is updated based on use_dma_api judgment

This bug does not occur because no driver use the premapped with indirect.

Reference

https://git.kernel.org/stable/c/e142169aca5546ae6619c39a575cda8105362100 https://git.kernel.org/stable/c/75450ff8c6fe8755bf5b139b238eaf9739cfd64e https://git.kernel.org/stable/c/51bacd9d29bf98c3ebc65e4a0477bb86306b4140 https://git.kernel.org/stable/c/d5c0ed17fea60cca9bc3bf1278b49ba79242bbcd