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-Tag: v4.4.190~59 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7c7404e189ace80315b51f454c9a8a60f24ebf01;p=thirdparty%2Fkernel%2Fstable.git scsi: megaraid_sas: fix panic on loading firmware crashdump [ Upstream commit 3b5f307ef3cb5022bfe3c8ca5b8f2114d5bf6c29 ] 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 Signed-off-by: Sasha Levin --- diff --git a/drivers/scsi/megaraid/megaraid_sas_base.c b/drivers/scsi/megaraid/megaraid_sas_base.c index 2422094f1f15c..5e0bac8de6381 100644 --- a/drivers/scsi/megaraid/megaraid_sas_base.c +++ b/drivers/scsi/megaraid/megaraid_sas_base.c @@ -2752,6 +2752,7 @@ megasas_fw_crash_buffer_show(struct device *cdev, u32 size; unsigned long buff_addr; unsigned long dmachunk = CRASH_DMA_BUF_SIZE; + unsigned long chunk_left_bytes; unsigned long src_addr; unsigned long flags; u32 buff_offset; @@ -2777,6 +2778,8 @@ megasas_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] +