On Tue, Mar 14, 2023 at 06:44:56AM -0700, Nikita Zhandarovich wrote:
> From: Nikita Zhandarovich <n.zhandarovich@xxxxxxxxxx>
>
> commit 5d9745cead1f121974322b94ceadfb4d1e67960e upstream.
>
> in_dev_get() can return NULL which will cause a failure once idev is
> dereferenced in in_dev_for_each_ifa_rtnl(). This patch adds a
> check for NULL value in idev beforehand.
>
> Found by Linux Verification Center (linuxtesting.org) with SVACE.
>
> Changes made to the original patch during backporting:
> Apply patch to drivers/infiniband/hw/i40iw/i40iw_cm.c instead of
> drivers/infiniband/hw/irdma/cm.c due to the fact that kernel versions
> 5.10 and below use i40iw driver, not irdma.
>
> Fixes: f27b4746f378 ("i40iw: add connection management code")
> Signed-off-by: Nikita Zhandarovich <n.zhandarovich@xxxxxxxxxx>
> Link: https://lore.kernel.org/r/20230126185230.62464-1-n.zhandarovich@xxxxxxxxxx
> ---
> drivers/infiniband/hw/i40iw/i40iw_cm.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/infiniband/hw/i40iw/i40iw_cm.c b/drivers/infiniband/hw/i40iw/i40iw_cm.c
> index 3053c345a5a3..e1236ac502f2 100644
> --- a/drivers/infiniband/hw/i40iw/i40iw_cm.c
> +++ b/drivers/infiniband/hw/i40iw/i40iw_cm.c
> @@ -1776,6 +1776,8 @@ static enum i40iw_status_code i40iw_add_mqh_4(
> const struct in_ifaddr *ifa;
>
> idev = in_dev_get(dev);
> + if (!idev)
> + continue;
>
> in_dev_for_each_ifa_rtnl(ifa, idev) {
> i40iw_debug(&iwdev->sc_dev,
As this isn't anything that can be triggered by a normal system
operation, I'm going to drop it from the review queue. Unless you have
a reproducer that can cause this to happen from userspace?
thanks,
greg k-h
