On Mar 19 17:12, Kaixuan Li wrote:
> Dear Sir or Madam,
> 
> Since my institution email address doesn't allow git email, I sent the
> patch manually as follows:
> 
> In nvme_abort(), the submission queue pointer is dereferenced from the
>   guest-controlled sqid before validating it with nvme_check_sqid():
> 
>       NvmeSQueue *sq = n->sq[sqid];
> 
>   Since sqid is a 16-bit value (range 0-65535) taken directly from CDW10,
>   and n->sq[] is typically only max_ioqpairs+1 (65) entries, a malicious
> guest can trigger an out-of-bounds heap read by sending an Abort command
>   with a large sqid.
> 
>   ASan reports this as heap-buffer-overflow in nvme_abort.
> 
>   Fix this by moving the array dereference to after the nvme_check_sqid()
>   bounds validation.
> 
>   Resolves: https://gitlab.com/qemu-project/qemu/-/issues/3348
>   Fixes: 75209c071a ("hw/nvme: actually implement abort")
>   Cc: [email protected]
>   Signed-off-by: Kaixuan Li <[email protected]>
>   ---
>    hw/nvme/ctrl.c | 4 +++-
>    1 file changed, 3 insertions(+), 1 deletion(-)
> 
>   diff --git a/hw/nvme/ctrl.c b/hw/nvme/ctrl.c
>   index cc4593cd42..be6c7028cb 100644
>   --- a/hw/nvme/ctrl.c
>   +++ b/hw/nvme/ctrl.c
>   @@ -6111,7 +6111,7 @@ static uint16_t nvme_abort(NvmeCtrl *n, NvmeRequest
> *req)
>    {
>        uint16_t sqid = le32_to_cpu(req->cmd.cdw10) & 0xffff;
>        uint16_t cid  = (le32_to_cpu(req->cmd.cdw10) >> 16) & 0xffff;
>   -    NvmeSQueue *sq = n->sq[sqid];
>   +    NvmeSQueue *sq;
>        NvmeRequest *r, *next;
>        int i;
> 
>   @@ -6120,6 +6120,8 @@ static uint16_t nvme_abort(NvmeCtrl *n, NvmeRequest
> *req)
>            return NVME_INVALID_FIELD | NVME_DNR;
>        }
> 
>   +    sq = n->sq[sqid];
>   +
>        if (sqid == 0) {
>            for (i = 0; i < n->outstanding_aers; i++) {
>                NvmeRequest *re = n->aer_reqs[i];
>   --
>   2.34.1
> 

Hi,

Thanks!

I'll queue it up on nvme-next.

Klaus

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