mirror of https://github.com/torvalds/linux.git
cp might be null, calling cp->cp_conn would produce null dereference
[Simon Horman adds:]
Analysis:
* cp is a parameter of __rds_rdma_map and is not reassigned.
* The following call-sites pass a NULL cp argument to __rds_rdma_map()
- rds_get_mr()
- rds_get_mr_for_dest
* Prior to the code above, the following assumes that cp may be NULL
(which is indicative, but could itself be unnecessary)
trans_private = rs->rs_transport->get_mr(
sg, nents, rs, &mr->r_key, cp ? cp->cp_conn : NULL,
args->vec.addr, args->vec.bytes,
need_odp ? ODP_ZEROBASED : ODP_NOT_NEEDED);
* The code modified by this patch is guarded by IS_ERR(trans_private),
where trans_private is assigned as per the previous point in this analysis.
The only implementation of get_mr that I could locate is rds_ib_get_mr()
which can return an ERR_PTR if the conn (4th) argument is NULL.
* ret is set to PTR_ERR(trans_private).
rds_ib_get_mr can return ERR_PTR(-ENODEV) if the conn (4th) argument is NULL.
Thus ret may be -ENODEV in which case the code in question will execute.
Conclusion:
* cp may be NULL at the point where this patch adds a check;
this patch does seem to address a possible bug
Fixes:
|
||
|---|---|---|
| .. | ||
| Kconfig | ||
| Makefile | ||
| af_rds.c | ||
| bind.c | ||
| cong.c | ||
| connection.c | ||
| ib.c | ||
| ib.h | ||
| ib_cm.c | ||
| ib_frmr.c | ||
| ib_mr.h | ||
| ib_rdma.c | ||
| ib_recv.c | ||
| ib_ring.c | ||
| ib_send.c | ||
| ib_stats.c | ||
| ib_sysctl.c | ||
| info.c | ||
| info.h | ||
| loop.c | ||
| loop.h | ||
| message.c | ||
| page.c | ||
| rdma.c | ||
| rdma_transport.c | ||
| rdma_transport.h | ||
| rds.h | ||
| rds_single_path.h | ||
| recv.c | ||
| send.c | ||
| stats.c | ||
| sysctl.c | ||
| tcp.c | ||
| tcp.h | ||
| tcp_connect.c | ||
| tcp_listen.c | ||
| tcp_recv.c | ||
| tcp_send.c | ||
| tcp_stats.c | ||
| threads.c | ||
| transport.c | ||