From 765a707000e838c30b18d712fe6cb3dd8e0435f3 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Mon, 2 Jan 2017 11:03:33 +0100 Subject: [PATCH] megasas: fix guest-triggered memory leak If the guest sets the sglist size to a value >=2GB, megasas_handle_dcmd will return MFI_STAT_MEMORY_NOT_AVAILABLE without freeing the memory. Avoid this by returning only the status from map_dcmd, and loading cmd->iov_size in the caller. Reported-by: Li Qiang Signed-off-by: Paolo Bonzini --- hw/scsi/megasas.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/hw/scsi/megasas.c b/hw/scsi/megasas.c index 67fc1e7..6233865 100644 --- a/hw/scsi/megasas.c +++ b/hw/scsi/megasas.c @@ -683,14 +683,14 @@ static int megasas_map_dcmd(MegasasState *s, MegasasCmd *cmd) trace_megasas_dcmd_invalid_sge(cmd->index, cmd->frame->header.sge_count); cmd->iov_size = 0; - return -1; + return -EINVAL; } iov_pa = megasas_sgl_get_addr(cmd, &cmd->frame->dcmd.sgl); iov_size = megasas_sgl_get_len(cmd, &cmd->frame->dcmd.sgl); pci_dma_sglist_init(&cmd->qsg, PCI_DEVICE(s), 1); qemu_sglist_add(&cmd->qsg, iov_pa, iov_size); cmd->iov_size = iov_size; - return cmd->iov_size; + return 0; } static void megasas_finish_dcmd(MegasasCmd *cmd, uint32_t iov_size) @@ -1559,19 +1559,20 @@ static const struct dcmd_cmd_tbl_t { static int megasas_handle_dcmd(MegasasState *s, MegasasCmd *cmd) { - int opcode, len; + int opcode; int retval = 0; + size_t len; const struct dcmd_cmd_tbl_t *cmdptr = dcmd_cmd_tbl; opcode = le32_to_cpu(cmd->frame->dcmd.opcode); trace_megasas_handle_dcmd(cmd->index, opcode); - len = megasas_map_dcmd(s, cmd); - if (len < 0) { + if (megasas_map_dcmd(s, cmd) < 0) { return MFI_STAT_MEMORY_NOT_AVAILABLE; } while (cmdptr->opcode != -1 && cmdptr->opcode != opcode) { cmdptr++; } + len = cmd->iov_size; if (cmdptr->opcode == -1) { trace_megasas_dcmd_unhandled(cmd->index, opcode, len); retval = megasas_dcmd_dummy(s, cmd); -- 1.8.3.1