From f13a6e5e2e0192737c3bdbdb16c5cc0181cc86e5 Mon Sep 17 00:00:00 2001 From: "Michael J. Ruhl" Date: Mon, 24 Jul 2017 07:46:42 -0700 Subject: [PATCH] IB/hfi1: Split copy_to_user data copy for better security A copy_to_user() call assumes that two members of a data structure are sequential. Since this may not always be true, separate the copies to ensure a safe copy. Reviewed-by: Dennis Dalessandro Signed-off-by: Michael J. Ruhl Signed-off-by: Dennis Dalessandro Signed-off-by: Doug Ledford --- drivers/infiniband/hw/hfi1/file_ops.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/infiniband/hw/hfi1/file_ops.c b/drivers/infiniband/hw/hfi1/file_ops.c index 7be75e0d4f7e..650c1e578775 100644 --- a/drivers/infiniband/hw/hfi1/file_ops.c +++ b/drivers/infiniband/hw/hfi1/file_ops.c @@ -268,12 +268,14 @@ static long hfi1_file_ioctl(struct file *fp, unsigned int cmd, /* * Copy the number of tidlist entries we used * and the length of the buffer we registered. - * These fields are adjacent in the structure so - * we can copy them at the same time. */ addr = arg + offsetof(struct hfi1_tid_info, tidcnt); if (copy_to_user((void __user *)addr, &tinfo.tidcnt, - sizeof(tinfo.tidcnt) + + sizeof(tinfo.tidcnt))) + return -EFAULT; + + addr = arg + offsetof(struct hfi1_tid_info, length); + if (copy_to_user((void __user *)addr, &tinfo.length, sizeof(tinfo.length))) ret = -EFAULT; } -- 2.30.2