[PATCH 32/32] esas2r: Use __mem_to_flex() with struct atto_ioctl

Kees Cook
2022-05-04T01:58:40Z

As part of the work to perform bounds checking on all memcpy() uses,
replace the open-coded a deserialization of bytes out of memory into a
trailing flexible array by using a flex_array.h helper to perform the
allocation, bounds checking, and copying. This requires adding the
flexible array explicitly.

Cc: Bradley Grove <linuxdrivers@attotech.com>
Cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: linux-scsi@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
drivers/scsi/esas2r/atioctl.h | 1 +
drivers/scsi/esas2r/esas2r_ioctl.c | 11 +++++++----
2 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/scsi/esas2r/atioctl.h b/drivers/scsi/esas2r/atioctl.h
index ff2ad9b38575..dd3437412ffc 100644
--- a/drivers/scsi/esas2r/atioctl.h
+++ b/drivers/scsi/esas2r/atioctl.h
@@ -831,6 +831,7 @@ struct __packed atto_hba_trace {
u32 total_length;
u32 trace_mask;
u8 reserved2[48];
+ u8 contents[];
};

#define ATTO_FUNC_SCSI_PASS_THRU 0x04
diff --git a/drivers/scsi/esas2r/esas2r_ioctl.c b/drivers/scsi/esas2r/esas2r_ioctl.c
index 08f4e43c7d9e..9310b54b1575 100644
--- a/drivers/scsi/esas2r/esas2r_ioctl.c
+++ b/drivers/scsi/esas2r/esas2r_ioctl.c
@@ -947,11 +947,14 @@ static int hba_ioctl_callback(struct esas2r_adapter *a,
break;
}

- memcpy(trc + 1,
- a->fw_coredump_buff + offset,
- len);
+ if (__mem_to_flex(hi, data.trace.contents,
+ data_length,
+ a->fw_coredump_buff + offset,
+ len)) {
+ hi->status = ATTO_STS_INV_FUNC;
+ break;
+ }

- hi->data_length = len;
} else if (trc->trace_func == ATTO_TRC_TF_RESET) {
memset(a->fw_coredump_buff, 0,
ESAS2R_FWCOREDUMP_SZ);
--
2.32.0