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| author | Mahmoud Adam <mngyadam@amazon.com> | 2024-03-26 16:31:33 +0100 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2024-03-29 12:04:09 -0700 |
| commit | 62fc3357e079a07a22465b9b6ef71bb6ea75ee4b (patch) | |
| tree | 543d3c1990fc5e3f3f980e2306b199cb82771507 /net/rds | |
| parent | 625aefac340f45a4fc60908da763f437599a0d6f (diff) | |
| download | linux-62fc3357e079a07a22465b9b6ef71bb6ea75ee4b.tar.gz linux-62fc3357e079a07a22465b9b6ef71bb6ea75ee4b.tar.bz2 linux-62fc3357e079a07a22465b9b6ef71bb6ea75ee4b.zip | |
net/rds: fix possible cp null dereference
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: c055fc00c07b ("net/rds: fix WARNING in rds_conn_connect_if_down")
Cc: stable@vger.kernel.org # v4.19+
Signed-off-by: Mahmoud Adam <mngyadam@amazon.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20240326153132.55580-1-mngyadam@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/rds')
| -rw-r--r-- | net/rds/rdma.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/rds/rdma.c b/net/rds/rdma.c index a4e3c5de998b..00dbcd4d28e6 100644 --- a/net/rds/rdma.c +++ b/net/rds/rdma.c @@ -302,7 +302,7 @@ static int __rds_rdma_map(struct rds_sock *rs, struct rds_get_mr_args *args, } ret = PTR_ERR(trans_private); /* Trigger connection so that its ready for the next retry */ - if (ret == -ENODEV) + if (ret == -ENODEV && cp) rds_conn_connect_if_down(cp->cp_conn); goto out; } |