{"id":"CVE-2026-97989","published":"2026-09-25T11:17:27.010","lastModified":"2026-09-25T11:17:27.010","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nvduse: validate virtqueue alignment\n\nvduse_validate_config() only checks the upper bound of vq_align. Invalid\nvalues can therefore reach vring_create_virtqueue_map(). The split-ring\nhelpers use align - 1 as a bit mask, so the alignment must be a non-zero\npower of two. A zero value makes vring_size() drop the descriptor and\navailable-ring part and vring_init() leave the used ring pointer NULL.\n\nThe VIRTIO spec requires the used ring to start at an address\naligned to at least 4 bytes. Reject values below VRING_USED_ALIGN_SIZE as\nwell as non-power-of-two values before they reach the virtio ring helpers.\n\nOpening a virtio-net device created with vq_align=0 triggered:\n\nBUG: KASAN: null-ptr-deref in virtqueue_kick_prepare_split+0xe3/0x100\nRead of size 2 at addr 0000000000000000 by task systemd-network/1062\n\nCall Trace (relevant frames):\n dump_stack_lvl\n print_report\n kasan_report\n __asan_load2\n virtqueue_kick_prepare_split+0xe3/0x100\n virtqueue_kick_prepare+0x40/0x60\n try_fill_recv+0x857/0x1250\n virtnet_open+0x189/0x460\n __dev_open+0x225/0x390\n __dev_change_flags+0x368/0x3b0\n netif_change_flags+0x56/0xc0\n do_setlink.isra.0+0x68c/0x1e30\n\nValidate the value before it reaches the virtio ring helpers.","cvssScore":null,"cvssSeverity":null,"cvssVector":null,"cwes":[],"vendors":[],"products":[],"references":[{"url":"https://git.kernel.org/stable/c/c3c3b0839a1197530cc18f535062fc84dbdfc885","tags":[]},{"url":"https://git.kernel.org/stable/c/fa2c25b4add57888acfa89e398389e267bff3dcf","tags":[]}],"exploitRefs":[],"hasPoc":false,"ai":null}