Fix CVE-2020-17380
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.
Assert that 's->data_count' is within fifo_buffer.
-> 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>
Suggested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
patch link: https://lists.nongnu.org/archive/html/qemu-devel/2020-09/msg01175.html
Signed-off-by: Jiajie Li <lijiajie11@hw.com>
