[PATCH 1/2] habanalabs: block scalar load_and_exe on external queue

From: Oded Gabbay
Date: Fri Jun 05 2020 - 16:22:45 EST


In Gaudi, the user can't execute scalar load_and_exe on external queue
because it can be a security hole. The driver doesn't parse the commands
being loaded and it can be msg_prot, which the user isn't allowed to use.

Signed-off-by: Oded Gabbay <oded.gabbay@xxxxxxxxx>
---
drivers/misc/habanalabs/gaudi/gaudi.c | 25 ++++++++++++++++++-
.../habanalabs/include/gaudi/gaudi_packets.h | 3 +++
2 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/drivers/misc/habanalabs/gaudi/gaudi.c b/drivers/misc/habanalabs/gaudi/gaudi.c
index 61f88e9884ce..f34ac8d35a14 100644
--- a/drivers/misc/habanalabs/gaudi/gaudi.c
+++ b/drivers/misc/habanalabs/gaudi/gaudi.c
@@ -3790,6 +3790,25 @@ static int gaudi_validate_dma_pkt_no_mmu(struct hl_device *hdev,
src_in_host);
}

+static int gaudi_validate_load_and_exe_pkt(struct hl_device *hdev,
+ struct hl_cs_parser *parser,
+ struct packet_load_and_exe *user_pkt)
+{
+ u32 cfg;
+
+ cfg = le32_to_cpu(user_pkt->cfg);
+
+ if (cfg & GAUDI_PKT_LOAD_AND_EXE_CFG_DST_MASK) {
+ dev_err(hdev->dev,
+ "User not allowed to use Load and Execute\n");
+ return -EPERM;
+ }
+
+ parser->patched_cb_size += sizeof(struct packet_load_and_exe);
+
+ return 0;
+}
+
static int gaudi_validate_cb(struct hl_device *hdev,
struct hl_cs_parser *parser, bool is_mmu)
{
@@ -3838,6 +3857,11 @@ static int gaudi_validate_cb(struct hl_device *hdev,
rc = -EPERM;
break;

+ case PACKET_LOAD_AND_EXE:
+ rc = gaudi_validate_load_and_exe_pkt(hdev, parser,
+ (struct packet_load_and_exe *) user_pkt);
+ break;
+
case PACKET_LIN_DMA:
parser->contains_dma_pkt = true;
if (is_mmu)
@@ -3855,7 +3879,6 @@ static int gaudi_validate_cb(struct hl_device *hdev,
case PACKET_FENCE:
case PACKET_NOP:
case PACKET_ARB_POINT:
- case PACKET_LOAD_AND_EXE:
parser->patched_cb_size += pkt_size;
break;

diff --git a/drivers/misc/habanalabs/include/gaudi/gaudi_packets.h b/drivers/misc/habanalabs/include/gaudi/gaudi_packets.h
index 9a5800b0086b..0f0cd067bb43 100644
--- a/drivers/misc/habanalabs/include/gaudi/gaudi_packets.h
+++ b/drivers/misc/habanalabs/include/gaudi/gaudi_packets.h
@@ -197,6 +197,9 @@ struct packet_wait {
__le32 ctl;
};

+#define GAUDI_PKT_LOAD_AND_EXE_CFG_DST_SHIFT 0
+#define GAUDI_PKT_LOAD_AND_EXE_CFG_DST_MASK 0x00000001
+
struct packet_load_and_exe {
__le32 cfg;
__le32 ctl;
--
2.17.1