CVE: CVE-2022-2962 Upstream-Status: Backport Signed-off-by: Ross Burton From 5c5c50b0a73d78ffe18336c9996fef5eae9bbbb0 Mon Sep 17 00:00:00 2001 From: Zheyu Ma Date: Sun, 21 Aug 2022 20:43:43 +0800 Subject: [PATCH] net: tulip: Restrict DMA engine to memories 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 Signed-off-by: Jason Wang --- 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 097e905bec..b9e42c322a 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); -- 2.34.1