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| author | Peilin Ye <yepeilin.cs@gmail.com> | 2020-07-30 22:20:26 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-08-05 11:06:50 +0300 |
| commit | 4b49b16999d4f875d1ba3bdf9e8e001d64b08d5e (patch) | |
| tree | 5cacae044abb794b0061bf4f6478dd53bc52a571 /net | |
| parent | 88f3814ffed51b37bda02642a3f93f8a979fb6e2 (diff) | |
| download | linux-4b49b16999d4f875d1ba3bdf9e8e001d64b08d5e.tar.xz | |
rds: Prevent kernel-infoleak in rds_notify_queue_get()
commit bbc8a99e952226c585ac17477a85ef1194501762 upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net')
| -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 c27cceae52e1..ef022d24f87a 100644 --- a/net/rds/recv.c +++ b/net/rds/recv.c @@ -453,12 +453,13 @@ 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 |