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[Qemu-devel] [PATCH v2] ide: ahci: add check before calling dma_memory_u
From: |
P J P |
Subject: |
[Qemu-devel] [PATCH v2] ide: ahci: add check before calling dma_memory_unmap |
Date: |
Fri, 29 Jan 2016 01:18:50 +0530 |
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>
---
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
diff --git a/hw/ide/ahci.c b/hw/ide/ahci.c
index 17f1cbd..f413a59 100644
--- a/hw/ide/ahci.c
+++ b/hw/ide/ahci.c
@@ -661,9 +661,11 @@ static bool ahci_map_fis_address(AHCIDevice *ad)
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(AHCIDevice *ad)
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)
--
2.5.0
- [Qemu-devel] [PATCH v2] ide: ahci: add check before calling dma_memory_unmap,
P J P <=