304d5426c4
fix CVE-2020-25743 patch link: https://lists.nongnu.org/archive/html/qemu-devel/2020-09/msg05967.html When canceling an i/o operation via ide_cancel_dam_sync(), a block pointer may be null. Add check to avoid null pointer dereference. -> https://ruhr-uni-bochum.sciebo.de/s/NNWP2GfwzYKeKwE?path=%2Fide_nullptr1 ==1803100==Hint: address points to the zero page. #0 blk_bs ../block/block-backend.c:714 #1 blk_drain ../block/block-backend.c:1715 #2 ide_cancel_dma_sync ../hw/ide/core.c:723 #3 bmdma_cmd_writeb ../hw/ide/core.c:723 #4 bmdma_write ../hw/ide/pci.c:298 #5 memory_region_write_accessor ../softmmu/memory.c:483 #6 access_with_adjusted_size ../softmmu/memory.c:544 #7 memory_region_dispatch_write ../softmmu/memory.c:1465 #8 flatview_write_continue ../exe.c:3176 ... Reported-by: Ruhr-University <bugs-syssec@rub.de> Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>