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[PATCH] sd: sdhci: check data_count is within fifo_buffer
From: |
P J P |
Subject: |
[PATCH] sd: sdhci: check data_count is within fifo_buffer |
Date: |
Thu, 27 Aug 2020 17:23:36 +0530 |
From: Prasad J Pandit <pjp@fedoraproject.org>
While doing multi block SDMA, transfer block size may exceed
the 's->fifo_buffer[s->buf_maxsz]' size. It may leave the
current element pointer 's->data_count' pointing out of bounds.
Leading the subsequent DMA r/w operation to OOB access issue.
Add check to avoid it.
-> https://ruhr-uni-bochum.sciebo.de/s/NNWP2GfwzYKeKwE?path=%2Fsdhci_oob_write1
==1459837==ERROR: AddressSanitizer: heap-buffer-overflow
WRITE of size 54722048 at 0x61500001e280 thread T3
#0 __interceptor_memcpy (/lib64/libasan.so.6+0x3a71d)
#1 flatview_read_continue ../exec.c:3245
#2 flatview_read ../exec.c:3278
#3 address_space_read_full ../exec.c:3291
#4 address_space_rw ../exec.c:3319
#5 dma_memory_rw_relaxed ../include/sysemu/dma.h:87
#6 dma_memory_rw ../include/sysemu/dma.h:110
#7 dma_memory_read ../include/sysemu/dma.h:116
#8 sdhci_sdma_transfer_multi_blocks ../hw/sd/sdhci.c:629
#9 sdhci_write ../hw/sd/sdhci.c:1097
#10 memory_region_write_accessor ../softmmu/memory.c:483
...
Reported-by: Ruhr-University <bugs-syssec@rub.de>
Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
---
hw/sd/sdhci.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/hw/sd/sdhci.c b/hw/sd/sdhci.c
index 1785d7e1f7..155e25ceee 100644
--- a/hw/sd/sdhci.c
+++ b/hw/sd/sdhci.c
@@ -604,6 +604,9 @@ static void sdhci_sdma_transfer_multi_blocks(SDHCIState *s)
s->blkcnt--;
}
}
+ if (s->data_count <= begin || s->data_count > s->buf_maxsz) {
+ break;
+ }
dma_memory_write(s->dma_as, s->sdmasysad,
&s->fifo_buffer[begin], s->data_count - begin);
s->sdmasysad += s->data_count - begin;
@@ -626,6 +629,9 @@ static void sdhci_sdma_transfer_multi_blocks(SDHCIState *s)
s->data_count = block_size;
boundary_count -= block_size - begin;
}
+ if (s->data_count <= begin || s->data_count > s->buf_maxsz) {
+ break;
+ }
dma_memory_read(s->dma_as, s->sdmasysad,
&s->fifo_buffer[begin], s->data_count - begin);
s->sdmasysad += s->data_count - begin;
--
2.26.2
- [PATCH] sd: sdhci: check data_count is within fifo_buffer,
P J P <=