diff options
| author | Peilin Ye <yepeilin.cs@gmail.com> | 2020-07-30 15:20:26 -0400 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2020-07-31 16:52:48 -0700 |
| commit | bbc8a99e952226c585ac17477a85ef1194501762 (patch) | |
| tree | 6e62fbfef1f8f51b488c3be4af8599b48f2cfefc /net/rds | |
| parent | dc096288d579c82efbf6f82a5d895fed6e41e5a6 (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')
| -rw-r--r-- | net/rds/recv.c | 3 |
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; LIST_HEAD(copy); 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 |