Robert Richter wrote: > If a faulty CXL memory device returns a broken zero LSA size in its > memory device information (Identify Memory Device (Opcode 4000h), CXL > spec. 3.1, 8.2.9.9.1.1), a divide error occurs in the libnvdimm > driver: > > Oops: divide error: 0000 [#1] PREEMPT SMP NOPTI > RIP: 0010:nd_label_data_init+0x10e/0x800 [libnvdimm] > > Code and flow: > > 1) CXL Command 4000h returns LSA size = 0 > 2) config_size is assigned to zero LSA size (CXL pmem driver): > > drivers/cxl/pmem.c: .config_size = mds->lsa_size, > > 3) max_xfer is set to zero (nvdimm driver): > > drivers/nvdimm/label.c: max_xfer = min_t(size_t, ndd->nsarea.max_xfer, > config_size); > > 4) A subsequent DIV_ROUND_UP() causes a division by zero: > > drivers/nvdimm/label.c: /* Make our initial read size a multiple of max_xfer > size */ > drivers/nvdimm/label.c: read_size = min(DIV_ROUND_UP(read_size, max_xfer) * > max_xfer, > drivers/nvdimm/label.c- config_size); > > Fix this by checking the config size parameter by extending an > existing check. > > Signed-off-by: Robert Richter <rrich...@amd.com> > Reviewed-by: Pankaj Gupta <pankaj.gu...@amd.com> > Reviewed-by: Ira Weiny <ira.we...@intel.com>
Applied to nvdimm/next Thanks, Ira [snip]
