mainline inclusion from mainline-v5.14-rc1 commit aeef9b4733c5c2356c75ba4f5c99e1a09ff1721d category: cleanup bugzilla: https://atomgit.com/src-openeuler/kernel/issues/19808 CVE: CVE-2026-97997 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- This patch moves next from vring_desc_state_packed to vring_desc_desc_extra_packed. This makes it simpler to let extra state to be reused by split virtqueue. Signed-off-by: Jason Wang <jasowang@redhat.com> Link: https://lore.kernel.org/r/20210604055350.58753-2-jasowang@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Jiacheng Yu <yujiacheng3@huawei.com> --- drivers/virtio/virtio_ring.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index a0a61f90cfbf..85c2becdd5f2 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -75,7 +75,6 @@ struct vring_desc_state_packed { void *data; /* Data for callback. */ struct vring_packed_desc *indir_desc; /* Indirect descriptor, if any. */ u16 num; /* Descriptor list length. */ - u16 next; /* The next desc state in a list. */ u16 last; /* The last desc state in a list. */ }; @@ -83,6 +82,7 @@ struct vring_desc_extra_packed { dma_addr_t addr; /* Buffer DMA addr. */ u32 len; /* Buffer length. */ u16 flags; /* Descriptor flags. */ + u16 next; /* The next desc state in a list. */ }; struct vring_virtqueue { @@ -1086,7 +1086,7 @@ static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq, 1 << VRING_PACKED_DESC_F_USED; } vq->packed.next_avail_idx = n; - vq->free_head = vq->packed.desc_state[id].next; + vq->free_head = vq->packed.desc_extra[id].next; /* Store token and indirect buffer state. */ vq->packed.desc_state[id].num = 1; @@ -1202,7 +1202,7 @@ static inline int virtqueue_add_packed(struct virtqueue *_vq, le16_to_cpu(flags); } prev = curr; - curr = vq->packed.desc_state[curr].next; + curr = vq->packed.desc_extra[curr].next; if ((unlikely(++i >= vq->packed.vring.num))) { i = 0; @@ -1323,7 +1323,7 @@ static void detach_buf_packed(struct vring_virtqueue *vq, /* Clear data ptr. */ state->data = NULL; - vq->packed.desc_state[state->last].next = vq->free_head; + vq->packed.desc_extra[state->last].next = vq->free_head; vq->free_head = id; vq->vq.num_free += state->num; @@ -1332,7 +1332,7 @@ static void detach_buf_packed(struct vring_virtqueue *vq, for (i = 0; i < state->num; i++) { vring_unmap_state_packed(vq, &vq->packed.desc_extra[curr]); - curr = vq->packed.desc_state[curr].next; + curr = vq->packed.desc_extra[curr].next; } } @@ -1690,8 +1690,6 @@ static struct virtqueue *vring_create_virtqueue_packed( /* Put everything in free lists. */ vq->free_head = 0; - for (i = 0; i < num-1; i++) - vq->packed.desc_state[i].next = i + 1; vq->packed.desc_extra = kmalloc_array(num, sizeof(struct vring_desc_extra_packed), @@ -1702,6 +1700,9 @@ static struct virtqueue *vring_create_virtqueue_packed( memset(vq->packed.desc_extra, 0, num * sizeof(struct vring_desc_extra_packed)); + for (i = 0; i < num - 1; i++) + vq->packed.desc_extra[i].next = i + 1; + /* No callback? Tell other side not to bother us. */ if (!callback) { vq->packed.event_flags_shadow = VRING_PACKED_EVENT_FLAG_DISABLE; -- 2.34.1

mainline inclusion from mainline-v5.14-rc1 commit 44593865b7c5f55bf587f297c72d682c671eea2b category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/19808 CVE: CVE-2026-97997 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- We should not depend on the DMA address, length and flag of descriptor table since they could be wrote with arbitrary value by the device. So this patch switches to use the stored one in desc_extra. Note that the indirect descriptors are fine since they are read-only streaming mappings. Signed-off-by: Jason Wang <jasowang@redhat.com> Link: https://lore.kernel.org/r/20210604055350.58753-5-jasowang@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Jiacheng Yu <yujiacheng3@huawei.com> --- drivers/virtio/virtio_ring.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index 80d13c2913e3..e1e1de519222 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -1246,13 +1246,16 @@ static inline int virtqueue_add_packed(struct virtqueue *_vq, unmap_release: err_idx = i; i = head; + curr = vq->free_head; vq->packed.avail_used_flags = avail_used_flags; for (n = 0; n < total_sg; n++) { if (i == err_idx) break; - vring_unmap_desc_packed(vq, &desc[i]); + vring_unmap_state_packed(vq, + &vq->packed.desc_extra[curr]); + curr = vq->packed.desc_extra[curr].next; i++; if (i >= vq->packed.vring.num) i = 0; -- 2.34.1

mainline inclusion from mainline-v7.3-rc3 commit 75d276e5bb68778b2916f98a2bc30f142ebadc64 category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/19808 CVE: CVE-2026-97997 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- In a packed ring the AVAIL and USED bits sit in the descriptor itself, so writing them makes that descriptor available. Those bit combinations flip meaning on every round of the ring, tracked by a wrap counter, so invalidating or validating a descriptor means inverting both bits. Commit 1ce9e6055fa0 ("virtio_ring: introduce packed ring support") has virtqueue_add_packed() make every descriptor of a chain available as it maps the chain, and write the head last. The device consumes the ring in order and stops at a head that is not available yet, so it never reaches the rest. When vring_map_one_sg() fails partway, unmap_release unmaps the segments and restores avail_used_flags, but the descriptors it wrote to in the ring stay marked with AVAIL and USED bits. The head is now the only entry that keeps the device from consuming these stale entries. For example, the ring would look like this now. Z - pre-previous command A - previous command B - aborted command C - current command [A1 DONE] [A2 DONE] <C1 EMPTY> [B2] [B3] [Z1 DONE] When the driver now attempts to issue the C command, the next add starts at the same head as B. If C spans less descriptors than B, there is no end marker because AVAIL and USED bits were still in place. And that means the device will start interpreting these stale entries (B2/B3) as another command entry, which then blocks the queue. This effect typically happens in swiotlb configurations under memory pressure, because vring_map_one_sg() can then fail with larger I/O requests which then leads to command abortions. There are broadly 2 ways to avoid leaving those flags behind: 1) Defer those flags too until the chain is complete. 2) Rewrite those flags for the previous wrap counter. Implement the second option in both packed add paths. The first option traverses the chain a second time on every successful add. The second option invalidates all added descriptors when any add fails. With this patch applied, a packed virtqueue keeps completing requests after a failed add. Fixes: 1ce9e6055fa0 ("virtio_ring: introduce packed ring support") Fixes: f6a15d854986 ("virtio_ring: add in order support") Assisted-by: Kiro:claude-opus-5 checkpatch sparse Signed-off-by: Alexander Graf <graf@amazon.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Message-ID: <20260817223229.28954-1-graf@amazon.com> Conflicts: drivers/virtio/virtio_ring.c [1. Context conflicts: this tree has no virtqueue_add_packed_in_order() (no in-order support), so that hunk is dropped and only the virtqueue_add_packed() path is adapted.] Signed-off-by: Jiacheng Yu <yujiacheng3@huawei.com> --- drivers/virtio/virtio_ring.c | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-) diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index 30051033dfda..534a1ae76791 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -1127,7 +1127,7 @@ static inline int virtqueue_add_packed(struct virtqueue *_vq, struct scatterlist *sg; unsigned int i, n, c, descs_used, err_idx; __le16 head_flags, flags; - u16 head, id, prev, curr, avail_used_flags; + u16 head, id, prev, curr, avail_used_flags, unpub_flags; int err; START_USE(vq); @@ -1249,15 +1249,30 @@ static inline int virtqueue_add_packed(struct virtqueue *_vq, curr = vq->free_head; vq->packed.avail_used_flags = avail_used_flags; + unpub_flags = avail_used_flags ^ (1 << VRING_PACKED_DESC_F_AVAIL | + 1 << VRING_PACKED_DESC_F_USED); for (n = 0; n < total_sg; n++) { if (i == err_idx) break; + /* + * The mapping loop made every descriptor but the head + * available. Stamp the previous wrap counter's AVAIL and USED + * bits on those, so that a later and shorter chain at this head + * does not leave one of them available beyond its own last + * descriptor. Marking them used instead would hand + * is_used_desc_packed() a completion we never made. + */ + if (i != head) + desc[i].flags = cpu_to_le16(unpub_flags); vring_unmap_extra_packed(vq, &vq->packed.desc_extra[curr]); curr = vq->packed.desc_extra[curr].next; i++; - if (i >= vq->packed.vring.num) + if (i >= vq->packed.vring.num) { i = 0; + unpub_flags ^= 1 << VRING_PACKED_DESC_F_AVAIL | + 1 << VRING_PACKED_DESC_F_USED; + } } END_USE(vq); -- 2.34.1