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 <junxiao.bi@oracle.com>
Acked-by: Sumit Saxena <sumit.saxena@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Junxiao Bi 2019-07-22 09:15:24 -07:00 committed by Greg Kroah-Hartman
parent 6e6026cd50
commit 7c7404e189

View file

@ -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] +