[PATCH] RDMA/nldev: validate dynamic counter attribute length

[Pengpeng Hou]

From: Pengpeng <pengpeng@xxxxxxxxxxx>

nldev_stat_set_counter_dynamic_doit() iterates nested hardware counter
attributes and reads each entry with nla_get_u32(). The nested container
proof does not by itself prove that each child attribute carries a
four-byte payload.

Reject hardware counter entries whose payload is shorter than a u32
before reading the index.

Signed-off-by: Pengpeng <pengpeng@xxxxxxxxxxx>
---
 drivers/infiniband/core/nldev.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/infiniband/core/nldev.c b/drivers/infiniband/core/nldev.c
index 02a0a9c0a4a6..40b323131c7b 100644
--- a/drivers/infiniband/core/nldev.c
+++ b/drivers/infiniband/core/nldev.c
@@ -2133,6 +2133,11 @@ static int nldev_stat_set_counter_dynamic_doit(struct nlattr *tb[],
 
 	nla_for_each_nested(entry_attr, tb[RDMA_NLDEV_ATTR_STAT_HWCOUNTERS],
 			    rem) {
+		if (nla_len(entry_attr) < sizeof(u32)) {
+			ret = -EINVAL;
+			goto out;
+		}
+
 		index = nla_get_u32(entry_attr);
 		if ((index >= stats->num_counters) ||
 		    !(stats->descs[index].flags & IB_STAT_FLAG_OPTIONAL)) {
-- 
2.43.0