From: Junxiao Bi Date: Mon, 22 Jul 2019 16:15:24 +0000 (-0700) Subject: scsi: megaraid_sas: fix panic on loading firmware crashdump X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=3b5f307ef3cb5022bfe3c8ca5b8f2114d5bf6c29;p=openwrt%2Fstaging%2Fblogic.git scsi: megaraid_sas: fix panic on loading firmware crashdump 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 Acked-by: Sumit Saxena Signed-off-by: Martin K. Petersen --- diff --git a/drivers/scsi/megaraid/megaraid_sas_base.c b/drivers/scsi/megaraid/megaraid_sas_base.c index 2590746c81e3..f9f07935556e 100644 --- a/drivers/scsi/megaraid/megaraid_sas_base.c +++ b/drivers/scsi/megaraid/megaraid_sas_base.c @@ -3163,6 +3163,7 @@ 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; @@ -3186,6 +3187,8 @@ 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] +