From 9e91782f3582e12f5c41e64f70e5c53f0e7b9f2a Mon Sep 17 00:00:00 2001 From: Prasad J Pandit Date: Tue, 24 May 2016 02:10:00 -0600 Subject: [PATCH] scsi: mptsas: infinite loop while fetching requests The LSI SAS1068 Host Bus Adapter emulator in Qemu, periodically looks for requests and fetches them. A loop doing that in mptsas_fetch_requests() could run infinitely if 's->state' was not operational. Move check to avoid such a loop. Reported-by: Li Qiang Signed-off-by: Prasad J Pandit [BR: CVE-2016-4964 BSC#981399] Signed-off-by: Bruce Rogers --- hw/scsi/mptsas.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/hw/scsi/mptsas.c b/hw/scsi/mptsas.c index 499c146..be88e16 100644 --- a/hw/scsi/mptsas.c +++ b/hw/scsi/mptsas.c @@ -754,11 +754,6 @@ static void mptsas_fetch_request(MPTSASState *s) hwaddr addr; int size; - if (s->state != MPI_IOC_STATE_OPERATIONAL) { - mptsas_set_fault(s, MPI_IOCSTATUS_INVALID_STATE); - return; - } - /* Read the message header from the guest first. */ addr = s->host_mfa_high_addr | MPTSAS_FIFO_GET(s, request_post); pci_dma_read(pci, addr, req, sizeof(hdr)); @@ -789,6 +784,10 @@ static void mptsas_fetch_requests(void *opaque) { MPTSASState *s = opaque; + if (s->state != MPI_IOC_STATE_OPERATIONAL) { + mptsas_set_fault(s, MPI_IOCSTATUS_INVALID_STATE); + return; + } while (!MPTSAS_FIFO_EMPTY(s, request_post)) { mptsas_fetch_request(s); }