| CVE: CVE-2018-20216 |
| Upstream-Status: Backport [https://git.qemu.org/?p=qemu.git;a=commit;h=f1e2e38] |
| |
| Signed-off-by: Kai Kang <kai.kang@windriver.com> |
| |
| From f1e2e38ee0136b7710a2caa347049818afd57a1b Mon Sep 17 00:00:00 2001 |
| From: Prasad J Pandit <pjp@fedoraproject.org> |
| Date: Thu, 13 Dec 2018 01:00:39 +0530 |
| Subject: [PATCH] pvrdma: check return value from pvrdma_idx_ring_has_ routines |
| |
| pvrdma_idx_ring_has_[data/space] routines also return invalid |
| index PVRDMA_INVALID_IDX[=-1], if ring has no data/space. Check |
| return value from these routines to avoid plausible infinite loops. |
| |
| Reported-by: Li Qiang <liq3ea@163.com> |
| Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org> |
| Reviewed-by: Yuval Shaia <yuval.shaia@oracle.com> |
| Signed-off-by: Marcel Apfelbaum <marcel.apfelbaum@gmail.com> |
| --- |
| hw/rdma/vmw/pvrdma_dev_ring.c | 29 +++++++++++------------------ |
| 1 file changed, 11 insertions(+), 18 deletions(-) |
| |
| diff --git a/hw/rdma/vmw/pvrdma_dev_ring.c b/hw/rdma/vmw/pvrdma_dev_ring.c |
| index 01247fc041..e8e5b502f6 100644 |
| --- a/hw/rdma/vmw/pvrdma_dev_ring.c |
| +++ b/hw/rdma/vmw/pvrdma_dev_ring.c |
| @@ -73,23 +73,16 @@ out: |
| |
| void *pvrdma_ring_next_elem_read(PvrdmaRing *ring) |
| { |
| + int e; |
| unsigned int idx = 0, offset; |
| |
| - /* |
| - pr_dbg("%s: t=%d, h=%d\n", ring->name, ring->ring_state->prod_tail, |
| - ring->ring_state->cons_head); |
| - */ |
| - |
| - if (!pvrdma_idx_ring_has_data(ring->ring_state, ring->max_elems, &idx)) { |
| + e = pvrdma_idx_ring_has_data(ring->ring_state, ring->max_elems, &idx); |
| + if (e <= 0) { |
| pr_dbg("No more data in ring\n"); |
| return NULL; |
| } |
| |
| offset = idx * ring->elem_sz; |
| - /* |
| - pr_dbg("idx=%d\n", idx); |
| - pr_dbg("offset=%d\n", offset); |
| - */ |
| return ring->pages[offset / TARGET_PAGE_SIZE] + (offset % TARGET_PAGE_SIZE); |
| } |
| |
| @@ -105,20 +98,20 @@ void pvrdma_ring_read_inc(PvrdmaRing *ring) |
| |
| void *pvrdma_ring_next_elem_write(PvrdmaRing *ring) |
| { |
| - unsigned int idx, offset, tail; |
| + int idx; |
| + unsigned int offset, tail; |
| |
| - /* |
| - pr_dbg("%s: t=%d, h=%d\n", ring->name, ring->ring_state->prod_tail, |
| - ring->ring_state->cons_head); |
| - */ |
| - |
| - if (!pvrdma_idx_ring_has_space(ring->ring_state, ring->max_elems, &tail)) { |
| + idx = pvrdma_idx_ring_has_space(ring->ring_state, ring->max_elems, &tail); |
| + if (idx <= 0) { |
| pr_dbg("CQ is full\n"); |
| return NULL; |
| } |
| |
| idx = pvrdma_idx(&ring->ring_state->prod_tail, ring->max_elems); |
| - /* TODO: tail == idx */ |
| + if (idx < 0 || tail != idx) { |
| + pr_dbg("invalid idx\n"); |
| + return NULL; |
| + } |
| |
| offset = idx * ring->elem_sz; |
| return ring->pages[offset / TARGET_PAGE_SIZE] + (offset % TARGET_PAGE_SIZE); |
| -- |
| 2.20.1 |
| |