path: root/net/rds/recv.c
diff options
authorPeilin Ye <yepeilin.cs@gmail.com>2020-07-30 15:20:26 -0400
committerDavid S. Miller <davem@davemloft.net>2020-07-31 16:52:48 -0700
commitbbc8a99e952226c585ac17477a85ef1194501762 (patch)
tree6e62fbfef1f8f51b488c3be4af8599b48f2cfefc /net/rds/recv.c
parentdc096288d579c82efbf6f82a5d895fed6e41e5a6 (diff)
rds: Prevent kernel-infoleak in rds_notify_queue_get()
rds_notify_queue_get() is potentially copying uninitialized kernel stack memory to userspace since the compiler may leave a 4-byte hole at the end of `cmsg`. In 2016 we tried to fix this issue by doing `= { 0 };` on `cmsg`, which unfortunately does not always initialize that 4-byte hole. Fix it by using memset() instead. Cc: stable@vger.kernel.org Fixes: f037590fff30 ("rds: fix a leak of kernel memory") Fixes: bdbe6fbc6a2f ("RDS: recv.c") Suggested-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Peilin Ye <yepeilin.cs@gmail.com> Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/rds/recv.c')
1 files changed, 2 insertions, 1 deletions
diff --git a/net/rds/recv.c b/net/rds/recv.c
index c8404971d5ab..aba4afe4dfed 100644
--- a/net/rds/recv.c
+++ b/net/rds/recv.c
@@ -450,12 +450,13 @@ static int rds_still_queued(struct rds_sock *rs, struct rds_incoming *inc,
int rds_notify_queue_get(struct rds_sock *rs, struct msghdr *msghdr)
struct rds_notifier *notifier;
- struct rds_rdma_notify cmsg = { 0 }; /* fill holes with zero */
+ struct rds_rdma_notify cmsg;
unsigned int count = 0, max_messages = ~0U;
unsigned long flags;
int err = 0;
+ memset(&cmsg, 0, sizeof(cmsg)); /* fill holes with zero */
/* put_cmsg copies to user space and thus may sleep. We can't do this
* with rs_lock held, so first grab as many notifications as we can stuff