From: Prasad J Pandit <p...@fedoraproject.org> While transferring data via fdctrl_write_data(), check that current drive does not have a null block pointer. Avoid null pointer dereference.
-> https://ruhr-uni-bochum.sciebo.de/s/NNWP2GfwzYKeKwE?path=%2Ffdc_nullptr1 ==1658854==Hint: address points to the zero page. #0 blk_inc_in_flight block/block-backend.c:1327 #1 blk_prw block/block-backend.c:1299 #2 blk_pwrite block/block-backend.c:1464 #3 fdctrl_write_data hw/block/fdc.c:2418 #4 fdctrl_write hw/block/fdc.c:962 #5 portio_write ioport.c:205 #6 memory_region_write_accessor memory.c:483 #7 access_with_adjusted_size memory.c:544 #8 memory_region_dispatch_write memory.c:1476 Reported-by: Ruhr-University <bugs-sys...@rub.de> Signed-off-by: Prasad J Pandit <p...@fedoraproject.org> --- hw/block/fdc.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/hw/block/fdc.c b/hw/block/fdc.c index e9ed3eef45..dedadac68a 100644 --- a/hw/block/fdc.c +++ b/hw/block/fdc.c @@ -2419,7 +2419,8 @@ static void fdctrl_write_data(FDCtrl *fdctrl, uint32_t value) if (pos == FD_SECTOR_LEN - 1 || fdctrl->data_pos == fdctrl->data_len) { cur_drv = get_cur_drv(fdctrl); - if (blk_pwrite(cur_drv->blk, fd_offset(cur_drv), fdctrl->fifo, + if (cur_drv->blk + && blk_pwrite(cur_drv->blk, fd_offset(cur_drv), fdctrl->fifo, BDRV_SECTOR_SIZE, 0) < 0) { FLOPPY_DPRINTF("error writing sector %d\n", fd_sector(cur_drv)); -- 2.26.2
