tree: https://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git sched/core head: 2dfdb3d20ad50e2ae2cb84cbceb0f0fc75e79e5d commit: 445d9e8ba05d5e9e4b26956b7fe529223e29d8d1 [13/19] sched: make struct sched_statistics independent of fair sched class config: x86_64-randconfig-m001-20210910 (attached as .config) compiler: gcc-9 (Debian 9.3.0-22) 9.3.0 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; Reported-by: Dan Carpenter <dan.carpenter(a)oracle.com&gt; smatch warnings: kernel/sched/debug.c:453 print_cfs_group_stats() warn: variable dereferenced before check 'se' (see line 444) vim +/se +453 kernel/sched/debug.c 3866e845ed5222 kernel/sched/debug.c Steven Rostedt (Red Hat 2016-02-22 439) ff9b48c3598732 kernel/sched_debug.c Bharata B Rao 2008-11-10 440 #ifdef CONFIG_FAIR_GROUP_SCHED 5091faa449ee0b kernel/sched_debug.c Mike Galbraith 2010-11-30 441 static void print_cfs_group_stats(struct seq_file *m, int cpu, struct task_group *tg) ff9b48c3598732 kernel/sched_debug.c Bharata B Rao 2008-11-10 442 { ff9b48c3598732 kernel/sched_debug.c Bharata B Rao 2008-11-10 443 struct sched_entity *se = tg->se[cpu]; 445d9e8ba05d5e kernel/sched/debug.c Yafang Shao 2021-09-05 @444 struct sched_statistics *stats = __schedstats_from_se(se); ^^ New unchecked dereference. ff9b48c3598732 kernel/sched_debug.c Bharata B Rao 2008-11-10 445 97fb7a0a8944bd kernel/sched/debug.c Ingo Molnar 2018-03-03 446 #define P(F) SEQ_printf(m, " .%-30s: %lld\n", #F, (long long)F) 445d9e8ba05d5e kernel/sched/debug.c Yafang Shao 2021-09-05 447 #define P_SCHEDSTAT(F) SEQ_printf(m, " .%-30s: %lld\n", \ 445d9e8ba05d5e kernel/sched/debug.c Yafang Shao 2021-09-05 448 #F, (long long)schedstat_val(stats->F)) 97fb7a0a8944bd kernel/sched/debug.c Ingo Molnar 2018-03-03 449 #define PN(F) SEQ_printf(m, " .%-30s: %lld.%06ld\n", #F, SPLIT_NS((long long)F)) 445d9e8ba05d5e kernel/sched/debug.c Yafang Shao 2021-09-05 450 #define PN_SCHEDSTAT(F) SEQ_printf(m, " .%-30s: %lld.%06ld\n", \ 445d9e8ba05d5e kernel/sched/debug.c Yafang Shao 2021-09-05 451 #F, SPLIT_NS((long long)schedstat_val(stats->F))) ff9b48c3598732 kernel/sched_debug.c Bharata B Rao 2008-11-10 452 cd126afe838d7e kernel/sched/debug.c Yuyang Du 2015-07-15 @453 if (!se) ^^^ The old code assumed "se" can be NULL. 18bf2805d9b30c kernel/sched/debug.c Ben Segall 2012-10-04 454 return; 18bf2805d9b30c kernel/sched/debug.c Ben Segall 2012-10-04 455 ff9b48c3598732 kernel/sched_debug.c Bharata B Rao 2008-11-10 456 PN(se->exec_start); ff9b48c3598732 kernel/sched_debug.c Bharata B Rao 2008-11-10 457 PN(se->vruntime); --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org