[qemu-xen stable-4.19] hw/nvme: fix oob memory read in fdp events log

[patchbot@xxxxxxx]

commit dd496f92b97a9a2d36f83a91d8adae90ba65465a
Author:     Klaus Jensen <k.jensen@xxxxxxxxxxx>
AuthorDate: Thu Aug 3 20:44:23 2023 +0200
Commit:     Michael Tokarev <mjt@xxxxxxxxxx>
CommitDate: Sun Sep 10 19:39:41 2023 +0300

    hw/nvme: fix oob memory read in fdp events log
    
    As reported by Trend Micro's Zero Day Initiative, an oob memory read
    vulnerability exists in nvme_fdp_events(). The host-provided offset is
    not verified.
    
    Fix this.
    
    This is only exploitable when Flexible Data Placement mode (fdp=on) is
    enabled.
    
    Fixes: CVE-2023-4135
    Fixes: 73064edfb864 ("hw/nvme: flexible data placement emulation")
    Reported-by: Trend Micro's Zero Day Initiative
    Signed-off-by: Klaus Jensen <k.jensen@xxxxxxxxxxx>
    (cherry picked from commit ecb1b7b082d3b7dceff0e486a114502fc52c0fdf)
    Signed-off-by: Michael Tokarev <mjt@xxxxxxxxxx>
---
 hw/nvme/ctrl.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/hw/nvme/ctrl.c b/hw/nvme/ctrl.c
index 812246689c..e16e19ead8 100644
--- a/hw/nvme/ctrl.c
+++ b/hw/nvme/ctrl.c
@@ -5092,6 +5092,11 @@ static uint16_t nvme_fdp_events(NvmeCtrl *n, uint32_t 
endgrpid,
     }
 
     log_size = sizeof(NvmeFdpEventsLog) + ebuf->nelems * sizeof(NvmeFdpEvent);
+
+    if (off >= log_size) {
+        return NVME_INVALID_FIELD | NVME_DNR;
+    }
+
     trans_len = MIN(log_size - off, buf_len);
     elog = g_malloc0(log_size);
     elog->num_events = cpu_to_le32(ebuf->nelems);
--
generated by git-patchbot for /home/xen/git/qemu-xen.git#stable-4.19