From: Prasad J Pandit <p...@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-sys...@rub.de> Signed-off-by: Prasad J Pandit <p...@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
