net: tulip: Restrict DMA engine to memories(CVE-2022-2962)

fix CVE-2022-2962.
The DMA engine is started by I/O access and then itself accesses the
I/O registers, triggering a teentrancy bug.
Fix this bug by restricting the DMA engine to memories regions.

Signed-off-by: Zhang Bo <oscar.zhangbo@huawei.com>

net-tulip-Restrict-DMA-engine-to-memories.patch

@@ -0,0 +1,62 @@
+From 828774ed550d33e1cf8bf4bbc2a0fcf6fdf22094 Mon Sep 17 00:00:00 2001
+From: Zhang Bo <oscar.zhangbo@huawei.com>
+Date: Fri, 30 Sep 2022 12:24:58 +0800
+Subject: [PATCH] net: tulip: Restrict DMA engine to memories
+
+fix CVE-2022-2962.
+The DMA engine is started by I/O access and then itself accesses the
+I/O registers, triggering a reentrancy bug.
+
+The following log can reveal it:
+==5637==ERROR: AddressSanitizer: stack-overflow
+    #0 0x5595435f6078 in tulip_xmit_list_update qemu/hw/net/tulip.c:673
+    #1 0x5595435f204a in tulip_write qemu/hw/net/tulip.c:805:13
+    #2 0x559544637f86 in memory_region_write_accessor qemu/softmmu/memory.c:492:5
+    #3 0x5595446379fa in access_with_adjusted_size qemu/softmmu/memory.c:554:18
+    #4 0x5595446372fa in memory_region_dispatch_write qemu/softmmu/memory.c
+    #5 0x55954468b74c in flatview_write_continue qemu/softmmu/physmem.c:2825:23
+    #6 0x559544683662 in flatview_write qemu/softmmu/physmem.c:2867:12
+    #7 0x5595446833f3 in address_space_write qemu/softmmu/physmem.c:2963:18
+    #8 0x5595435fb082 in dma_memory_rw_relaxed qemu/include/sysemu/dma.h:87:12
+    #9 0x5595435fb082 in dma_memory_rw qemu/include/sysemu/dma.h:130:12
+    #10 0x5595435fb082 in dma_memory_write qemu/include/sysemu/dma.h:171:12
+    #11 0x5595435fb082 in stl_le_dma qemu/include/sysemu/dma.h:272:1
+    #12 0x5595435fb082 in stl_le_pci_dma qemu/include/hw/pci/pci.h:910:1
+    #13 0x5595435fb082 in tulip_desc_write qemu/hw/net/tulip.c:101:9
+    #14 0x5595435f7e3d in tulip_xmit_list_update qemu/hw/net/tulip.c:706:9
+    #15 0x5595435f204a in tulip_write qemu/hw/net/tulip.c:805:13
+
+Fix this bug by restricting the DMA engine to memories regions.
+
+Signed-off-by: Zheyu Ma <zheyuma97@gmail.com>
+Signed-off-by: Jason Wang <jasowang@redhat.com>
+Signed-off-by: Zhang Bo <oscar.zhangbo@huawei.com>
+---
+ hw/net/tulip.c | 4 ++--
+ 1 file changed, 2 insertions(+), 2 deletions(-)
+
+diff --git a/hw/net/tulip.c b/hw/net/tulip.c
+index d5b6cc5ee6..5f8badefca 100644
+--- a/hw/net/tulip.c
++++ b/hw/net/tulip.c
+@@ -70,7 +70,7 @@ static const VMStateDescription vmstate_pci_tulip = {
+ static void tulip_desc_read(TULIPState *s, hwaddr p,
+         struct tulip_descriptor *desc)
+ {
+-    const MemTxAttrs attrs = MEMTXATTRS_UNSPECIFIED;
++    const MemTxAttrs attrs = { .memory = true };
+ 
+     if (s->csr[0] & CSR0_DBO) {
+         ldl_be_pci_dma(&s->dev, p, &desc->status, attrs);
+@@ -88,7 +88,7 @@ static void tulip_desc_read(TULIPState *s, hwaddr p,
+ static void tulip_desc_write(TULIPState *s, hwaddr p,
+         struct tulip_descriptor *desc)
+ {
+-    const MemTxAttrs attrs = MEMTXATTRS_UNSPECIFIED;
++    const MemTxAttrs attrs = { .memory = true };
+ 
+     if (s->csr[0] & CSR0_DBO) {
+         stl_be_pci_dma(&s->dev, p, desc->status, attrs);
+-- 
+2.27.0
+

qemu.spec

@@ -1,6 +1,6 @@
 Name: qemu
 Version: 6.2.0
-Release: 49
+Release: 50
 Epoch: 10
 Summary: QEMU is a generic and open source machine emulator and virtualizer
 License: GPLv2 and BSD and MIT and CC-BY-SA-4.0
@@ -304,6 +304,7 @@ Patch0291: tests-qtest-Add-fuzz-lsi53c895a-test.patch
 Patch0292: scsi-lsi53c895a-fix-use-after-free-in-lsi_do_msgout-.patch
 Patch0293: scsi-lsi53c895a-really-fix-use-after-free-in-lsi_do_.patch
 Patch0294: hw-usb-hcd-xhci-Fix-unbounded-loop-in-xhci_ring_chai.patch
+Patch0295: net-tulip-Restrict-DMA-engine-to-memories-CVE-2022-2.patch
 
 BuildRequires: flex
 BuildRequires: gcc
@@ -816,6 +817,9 @@ getent passwd qemu >/dev/null || \
 %endif
 
 %changelog
+* Fri Sep 30 2022 zhangbo <oscar.zhangbo@huawei.com> - 10:6.2.0-50
+- net: tulip: Restrict DMA engine to memories (CVE-2020-14394)
+
 * Sat Sep 03 2022 yezengruan <yezengruan@huawei.com> - 10:6.2.0-49
 - hw/usb/hcd-xhci: Fix unbounded loop in xhci_ring_chain_length() (CVE-2020-14394)