Re: [PATCH net-next v2 12/16] net: bridge: mcast: install S,G entries automatically based on reports

On Wed, 2020-09-23 at 16:13 +0800, kernel test robot wrote:

Hi Nikolay,

I love your patch! Perhaps something to improve:

[auto build test WARNING on net-next/master]

url:    https://github.com/0day-ci/linux/commits/Nikolay-Aleksandrov/net-bridge-mcast-IGMPv3-MLDv2-fast-path-part-2/20200922-153321
base:   https://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git 92ec804f3dbf0d986f8e10850bfff14f316d7aaf
config: i386-randconfig-m021-20200923 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-15) 9.3.0

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <redacted>

New smatch warnings:
net/bridge/br_multicast.c:980 __br_multicast_add_group() error: potential null dereference 'mp'.  (br_multicast_new_group returns null)

Old smatch warnings:
include/linux/u64_stats_sync.h:128 u64_stats_update_begin() warn: statement has no effect 31

This report is wrong, br_multicast_new_group() cannot return NULL.
It always returns ERR_PTR() of whatever error happened and there
is an IS_ERR() check afterwards.

Thanks.