From fd6918556736ecce8b10acd581ba134ffb62d9f9 Mon Sep 17 00:00:00 2001 From: Prasad J Pandit Date: Thu, 14 May 2020 00:55:39 +0530 Subject: [PATCH] megasas: avoid NULL pointer dereference While in megasas_handle_frame(), megasas_enqueue_frame() may set a NULL frame into MegasasCmd object for a given 'frame_addr' address. Add check to avoid a NULL pointer dereference issue. Reported-by: Alexander Bulekov Fixes: https://bugs.launchpad.net/qemu/+bug/1878259 Signed-off-by: Prasad J Pandit Acked-by: Alexander Bulekov Reviewed-by: Darren Kenny Message-Id: <20200513192540.1583887-3-ppandit@redhat.com> Signed-off-by: Paolo Bonzini --- hw/scsi/megasas.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/hw/scsi/megasas.c b/hw/scsi/megasas.c index 6ce598cd69..b531d88a9b 100644 --- a/hw/scsi/megasas.c +++ b/hw/scsi/megasas.c @@ -504,7 +504,7 @@ static MegasasCmd *megasas_enqueue_frame(MegasasState *s, cmd->pa = frame; /* Map all possible frames */ cmd->frame = pci_dma_map(pcid, frame, &frame_size_p, 0); - if (frame_size_p != frame_size) { + if (!cmd->frame || frame_size_p != frame_size) { trace_megasas_qf_map_failed(cmd->index, (unsigned long)frame); if (cmd->frame) { megasas_unmap_frame(s, cmd); -- 2.11.4.GIT