5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Aurelien DESBRIERES [ Upstream commit 54bf38b27afc08a0eb6b732f9c14eb8a4bcb66b5 ] usr_len is read from a network-supplied message field (le16_to_cpu) and used to compute data_len = off - usr_len without validating that usr_len <= off. A malicious RDMA client can send usr_len > off causing an integer underflow, resulting in data_len wrapping to a huge size_t value which is then passed to the rdma_ev callback as a memory length, leading to out-of-bounds memory access. Fix by reading and validating usr_len <= off before rtrs_srv_get_ops_ids() in both process_read() and process_write(), ensuring the early return path acquires no reference and has no resource leak. Link: https://patch.msgid.link/r/20260608134802.5019-1-aurelien@hackers.camp Reported-by: Aurelien DESBRIERES Reviewed-by: Md Haris Iqbal Signed-off-by: Aurelien DESBRIERES Assisted-by: Claude Acked-by: Md Haris Iqbal Signed-off-by: Jason Gunthorpe Signed-off-by: Sasha Levin --- drivers/infiniband/ulp/rtrs/rtrs-srv.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/drivers/infiniband/ulp/rtrs/rtrs-srv.c b/drivers/infiniband/ulp/rtrs/rtrs-srv.c index b7f7e24807dfb..455d315dcebf5 100644 --- a/drivers/infiniband/ulp/rtrs/rtrs-srv.c +++ b/drivers/infiniband/ulp/rtrs/rtrs-srv.c @@ -1047,6 +1047,11 @@ static void process_read(struct rtrs_srv_con *con, "Processing read request failed, invalid message\n"); return; } + usr_len = le16_to_cpu(msg->usr_len); + if (usr_len > off) { + pr_debug("rtrs-srv: Invalid usr_len %zu > off %u\n", usr_len, off); + return; + } rtrs_srv_get_ops_ids(srv_path); rtrs_srv_update_rdma_stats(srv_path->stats, off, READ); id = srv_path->ops_ids[buf_id]; @@ -1054,7 +1059,6 @@ static void process_read(struct rtrs_srv_con *con, id->dir = READ; id->msg_id = buf_id; id->rd_msg = msg; - usr_len = le16_to_cpu(msg->usr_len); data_len = off - usr_len; data = page_address(srv->chunks[buf_id]); ret = ctx->ops.rdma_ev(srv->priv, id, READ, data, data_len, @@ -1100,6 +1104,11 @@ static void process_write(struct rtrs_srv_con *con, rtrs_srv_state_str(srv_path->state)); return; } + usr_len = le16_to_cpu(req->usr_len); + if (usr_len > off) { + pr_debug("rtrs-srv: Invalid usr_len %zu > off %u\n", usr_len, off); + return; + } rtrs_srv_get_ops_ids(srv_path); rtrs_srv_update_rdma_stats(srv_path->stats, off, WRITE); id = srv_path->ops_ids[buf_id]; @@ -1107,7 +1116,6 @@ static void process_write(struct rtrs_srv_con *con, id->dir = WRITE; id->msg_id = buf_id; - usr_len = le16_to_cpu(req->usr_len); data_len = off - usr_len; data = page_address(srv->chunks[buf_id]); ret = ctx->ops.rdma_ev(srv->priv, id, WRITE, data, data_len, -- 2.53.0