On Mon, Jul 22, 2019 at 9:45 PM Junxiao Bi <junxiao.bi@xxxxxxxxxx> wrote: > > While loading fw crashdump in function fw_crash_buffer_show(), > left bytes in one dma chunk was not checked, if copying size > over it, overflow access will cause kernel panic. > > Signed-off-by: Junxiao Bi <junxiao.bi@xxxxxxxxxx> Acked-by: Sumit Saxena <sumit.saxena@xxxxxxxxxxxx> > --- > drivers/scsi/megaraid/megaraid_sas_base.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/scsi/megaraid/megaraid_sas_base.c b/drivers/scsi/megaraid/megaraid_sas_base.c > index 80ab9700f1de..3eef0858fa8e 100644 > --- a/drivers/scsi/megaraid/megaraid_sas_base.c > +++ b/drivers/scsi/megaraid/megaraid_sas_base.c > @@ -3153,6 +3153,7 @@ fw_crash_buffer_show(struct device *cdev, > (struct megasas_instance *) shost->hostdata; > u32 size; > unsigned long dmachunk = CRASH_DMA_BUF_SIZE; > + unsigned long chunk_left_bytes; > unsigned long src_addr; > unsigned long flags; > u32 buff_offset; > @@ -3176,6 +3177,8 @@ fw_crash_buffer_show(struct device *cdev, > } > > size = (instance->fw_crash_buffer_size * dmachunk) - buff_offset; > + chunk_left_bytes = dmachunk - (buff_offset % dmachunk); > + size = (size > chunk_left_bytes) ? chunk_left_bytes : size; > size = (size >= PAGE_SIZE) ? (PAGE_SIZE - 1) : size; > > src_addr = (unsigned long)instance->crash_buf[buff_offset / dmachunk] + > -- > 2.17.1 >
