Bugzilla: 1096195 Upstream-status: 3.15 and queued for stable From ef87dbe7614341c2e7bfe8d32fcb7028cc97442c Mon Sep 17 00:00:00 2001 From: Matthew Daley Date: Mon, 28 Apr 2014 19:05:20 +1200 Subject: floppy: ignore kernel-only members in FDRAWCMD ioctl input From: Matthew Daley commit ef87dbe7614341c2e7bfe8d32fcb7028cc97442c upstream. Always clear out these floppy_raw_cmd struct members after copying the entire structure from userspace so that the in-kernel version is always valid and never left in an interdeterminate state. Signed-off-by: Matthew Daley Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- drivers/block/floppy.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) --- a/drivers/block/floppy.c +++ b/drivers/block/floppy.c @@ -3107,10 +3107,11 @@ loop: return -ENOMEM; *rcmd = ptr; ret = copy_from_user(ptr, param, sizeof(*ptr)); - if (ret) - return -EFAULT; ptr->next = NULL; ptr->buffer_length = 0; + ptr->kernel_data = NULL; + if (ret) + return -EFAULT; param += sizeof(struct floppy_raw_cmd); if (ptr->cmd_count > 33) /* the command may now also take up the space @@ -3126,7 +3127,6 @@ loop: for (i = 0; i < 16; i++) ptr->reply[i] = 0; ptr->resultcode = 0; - ptr->kernel_data = NULL; if (ptr->flags & (FD_RAW_READ | FD_RAW_WRITE)) { if (ptr->length <= 0)