| From: Prasad J Pandit <address@hidden> |
| |
| When IDE AHCI emulation uses Frame Information Structures(FIS) |
| engine for data transfer, the mapped FIS buffer address is stored |
| in a static 'bounce.buffer'. When a request is made to map another |
| memory region, address_space_map() returns NULL because |
| 'bounce.buffer' is in_use. It leads to a null pointer dereference |
| error while doing 'dma_memory_unmap'. Add a check to avoid it. |
| |
| Reported-by: Zuozhi fzz <address@hidden> |
| Signed-off-by: Prasad J Pandit <address@hidden> |
| |
| Upstream-Status: Backport |
| https://lists.gnu.org/archive/html/qemu-devel/2016-01/msg05740.html |
| |
| CVE: CVE-2016-2197 |
| Signed-off-by: Armin Kuster <akuster@mvista.com> |
| |
| --- |
| hw/ide/ahci.c | 16 ++++++++++------ |
| 1 file changed, 10 insertions(+), 6 deletions(-) |
| |
| Update as per review |
| -> https://lists.gnu.org/archive/html/qemu-devel/2016-01/msg05715.html |
| |
| Index: qemu-2.5.0/hw/ide/ahci.c |
| =================================================================== |
| --- qemu-2.5.0.orig/hw/ide/ahci.c |
| +++ qemu-2.5.0/hw/ide/ahci.c |
| @@ -661,9 +661,11 @@ static bool ahci_map_fis_address(AHCIDev |
| |
| static void ahci_unmap_fis_address(AHCIDevice *ad) |
| { |
| - dma_memory_unmap(ad->hba->as, ad->res_fis, 256, |
| - DMA_DIRECTION_FROM_DEVICE, 256); |
| - ad->res_fis = NULL; |
| + if (ad->res_fis) { |
| + dma_memory_unmap(ad->hba->as, ad->res_fis, 256, |
| + DMA_DIRECTION_FROM_DEVICE, 256); |
| + ad->res_fis = NULL; |
| + } |
| } |
| |
| static bool ahci_map_clb_address(AHCIDevice *ad) |
| @@ -677,9 +679,11 @@ static bool ahci_map_clb_address(AHCIDev |
| |
| static void ahci_unmap_clb_address(AHCIDevice *ad) |
| { |
| - dma_memory_unmap(ad->hba->as, ad->lst, 1024, |
| - DMA_DIRECTION_FROM_DEVICE, 1024); |
| - ad->lst = NULL; |
| + if (ad->lst) { |
| + dma_memory_unmap(ad->hba->as, ad->lst, 1024, |
| + DMA_DIRECTION_FROM_DEVICE, 1024); |
| + ad->lst = NULL; |
| + } |
| } |
| |
| static void ahci_write_fis_sdb(AHCIState *s, NCQTransferState *ncq_tfs) |