Skip to content

harden(incoming): read DATA seg.offset as u32 in homa_copy_to_user #100

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
randomizedcoder wants to merge 1 commit into
base: main
Choose a base branch
from
+25 −1
Open

harden(incoming): read DATA seg.offset as u32 in homa_copy_to_user #100

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
2 changes: 1 addition & 1 deletion homa_incoming.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -395,7 +395,7 @@ int homa_copy_to_user(struct homa_rpc *rpc)
struct homa_data_hdr *h = (struct homa_data_hdr *)
skbs[i]->data;
int pkt_length = homa_data_len(skbs[i]);
int offset = ntohl(h->seg.offset);
u32 offset = ntohl(h->seg.offset);
int buf_bytes, chunk_size;
struct iov_iter iter;
int copied = 0;
Expand Down
24 changes: 24 additions & 0 deletions test/unit_homa_incoming.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1754,6 +1754,30 @@ TEST_F(homa_incoming, homa_data_pkt__homa_add_packet_returns_error)
EXPECT_EQ(1, mock_num_drop_reasons);
EXPECT_EQ(SKB_DROP_REASON_PKT_TOO_BIG, mock_drop_reasons[0]);
}
TEST_F(homa_incoming, homa_data_pkt__seg_offset_is_unsigned)
{
/* A DATA seg.offset is an unsigned wire field. homa_add_packet()
* validates it as u32 before the packet is queued, so an offset with
* the top bit set is rejected as PKT_TOO_BIG (it is >= msgin.length,
* which is capped at HOMA_MAX_MESSAGE_LENGTH) and never reaches the
* copy-out path. This characterizes that boundary and guards the u32
* handling in homa_copy_to_user's offset.
*/
struct homa_rpc *crpc = unit_client_rpc(&self->hsk,
UNIT_OUTGOING, self->client_ip, self->server_ip,
self->server_port, self->client_id, 1000, 1600);

ASSERT_NE(NULL, crpc);
unit_log_clear();
crpc->msgout.next_xmit_offset = crpc->msgout.length;
self->data.message_length = htonl(1600);
self->data.seg.offset = htonl(0x80000000);
homa_data_pkt(mock_skb_alloc(self->server_ip, self->client_ip,
&self->data.common, 1400, 0), crpc);
EXPECT_EQ(0, skb_queue_len(&crpc->msgin.packets));
EXPECT_EQ(1, mock_num_drop_reasons);
EXPECT_EQ(SKB_DROP_REASON_PKT_TOO_BIG, mock_drop_reasons[0]);
}
TEST_F(homa_incoming, homa_data_pkt__handoff)
{
struct homa_rpc *crpc = unit_client_rpc(&self->hsk,
Expand Down