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authorPhilippe Mathieu-Daudé2021-12-15 21:56:55 +0100
committerThomas Huth2022-03-21 10:25:21 +0100
commit799f7f0104a3f2e0fea06ee7b31a1c293cd7c948 (patch)
tree46adece456cbd8aac87d9a58ff24b24ce6d50858 /hw/sd
parenthw/sd/sdhci: Honor failed DMA transactions (diff)
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hw/sd/sdhci: Prohibit DMA accesses to devices
The issue reported by OSS-Fuzz produces the following backtrace: ==447470==ERROR: AddressSanitizer: heap-buffer-overflow READ of size 1 at 0x61500002a080 thread T0 #0 0x71766d47 in sdhci_read_dataport hw/sd/sdhci.c:474:18 #1 0x7175f139 in sdhci_read hw/sd/sdhci.c:1022:19 #2 0x721b937b in memory_region_read_accessor softmmu/memory.c:440:11 #3 0x72171e51 in access_with_adjusted_size softmmu/memory.c:554:18 #4 0x7216f47c in memory_region_dispatch_read1 softmmu/memory.c:1424:16 #5 0x7216ebb9 in memory_region_dispatch_read softmmu/memory.c:1452:9 #6 0x7212db5d in flatview_read_continue softmmu/physmem.c:2879:23 #7 0x7212f958 in flatview_read softmmu/physmem.c:2921:12 #8 0x7212f418 in address_space_read_full softmmu/physmem.c:2934:18 #9 0x721305a9 in address_space_rw softmmu/physmem.c:2962:16 #10 0x7175a392 in dma_memory_rw_relaxed include/sysemu/dma.h:89:12 #11 0x7175a0ea in dma_memory_rw include/sysemu/dma.h:132:12 #12 0x71759684 in dma_memory_read include/sysemu/dma.h:152:12 #13 0x7175518c in sdhci_do_adma hw/sd/sdhci.c:823:27 #14 0x7174bf69 in sdhci_data_transfer hw/sd/sdhci.c:935:13 #15 0x7176aaa7 in sdhci_send_command hw/sd/sdhci.c:376:9 #16 0x717629ee in sdhci_write hw/sd/sdhci.c:1212:9 #17 0x72172513 in memory_region_write_accessor softmmu/memory.c:492:5 #18 0x72171e51 in access_with_adjusted_size softmmu/memory.c:554:18 #19 0x72170766 in memory_region_dispatch_write softmmu/memory.c:1504:16 #20 0x721419ee in flatview_write_continue softmmu/physmem.c:2812:23 #21 0x721301eb in flatview_write softmmu/physmem.c:2854:12 #22 0x7212fca8 in address_space_write softmmu/physmem.c:2950:18 #23 0x721d9a53 in qtest_process_command softmmu/qtest.c:727:9 A DMA descriptor is previously filled in RAM. An I/O access to the device (frames #22 to #16) start the DMA engine (frame #13). The engine fetch the descriptor and execute the request, which itself accesses the SDHCI I/O registers (frame #1 and #0), triggering a re-entrancy issue. Fix by prohibit transactions from the DMA to devices. The DMA engine is thus restricted to memories. Reported-by: OSS-Fuzz (Issue 36391) Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Reviewed-by: Thomas Huth <thuth@redhat.com> Resolves: https://gitlab.com/qemu-project/qemu/-/issues/451 Message-Id: <20211215205656.488940-3-philmd@redhat.com> Signed-off-by: Thomas Huth <thuth@redhat.com>
Diffstat (limited to 'hw/sd')
-rw-r--r--hw/sd/sdhci.c5
1 files changed, 3 insertions, 2 deletions
diff --git a/hw/sd/sdhci.c b/hw/sd/sdhci.c
index fe2f21f0c3..0e5e988927 100644
--- a/hw/sd/sdhci.c
+++ b/hw/sd/sdhci.c
@@ -741,6 +741,7 @@ static void sdhci_do_adma(SDHCIState *s)
{
unsigned int begin, length;
const uint16_t block_size = s->blksize & BLOCK_SIZE_MASK;
+ const MemTxAttrs attrs = { .memory = true };
ADMADescr dscr = {};
MemTxResult res;
int i;
@@ -794,7 +795,7 @@ static void sdhci_do_adma(SDHCIState *s)
res = dma_memory_write(s->dma_as, dscr.addr,
&s->fifo_buffer[begin],
s->data_count - begin,
- MEMTXATTRS_UNSPECIFIED);
+ attrs);
if (res != MEMTX_OK) {
break;
}
@@ -823,7 +824,7 @@ static void sdhci_do_adma(SDHCIState *s)
res = dma_memory_read(s->dma_as, dscr.addr,
&s->fifo_buffer[begin],
s->data_count - begin,
- MEMTXATTRS_UNSPECIFIED);
+ attrs);
if (res != MEMTX_OK) {
break;
}