The standard BIOS disk read/write request interface should never get a request for more than 64K of data. Explicitly check for overly large requests and reject them. This way, the low-level drivers do not need to check for or attempt to handle very large requests.
Signed-off-by: Kevin O'Connor kevin@koconnor.net --- src/block.c | 4 ++++ src/disk.c | 2 ++ 2 files changed, 6 insertions(+)
diff --git a/src/block.c b/src/block.c index 43af305..3f7ecb1 100644 --- a/src/block.c +++ b/src/block.c @@ -485,6 +485,10 @@ process_op(struct disk_op_s *op) { ASSERT16(); int ret, origcount = op->count; + if (origcount * GET_GLOBALFLAT(op->drive_gf->blksize) > 64*1024) { + op->count = 0; + return DISK_RET_EBOUNDARY; + } u8 type = GET_GLOBALFLAT(op->drive_gf->type); switch (type) { case DTYPE_FLOPPY: diff --git a/src/disk.c b/src/disk.c index fe2e2c3..0e0af24 100644 --- a/src/disk.c +++ b/src/disk.c @@ -173,6 +173,7 @@ disk_1300(struct bregs *regs, struct drive_s *drive_gf) struct disk_op_s dop; dop.drive_gf = drive_gf; dop.command = CMD_RESET; + dop.count = 0; int status = send_disk_op(&dop); disk_ret(regs, status); } @@ -322,6 +323,7 @@ disk_1310(struct bregs *regs, struct drive_s *drive_gf) struct disk_op_s dop; dop.drive_gf = drive_gf; dop.command = CMD_ISREADY; + dop.count = 0; int status = send_disk_op(&dop); disk_ret(regs, status); }