On Wed, 26 Jan 2022 13:14:22 +0300 Dan Carpenter wrote: > tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master > head: dd81e1c7d5fb126e5fbc5c9e334d7b3ec29a16a0 > commit: 9ec5a7d16899ed9062cc4c3dd3a13e1771411ab3 tracing: Change event_command func() to parse() > config: x86_64-randconfig-m001-20220124 (https://download.01.org/0day-ci/archive/20220125/202201250054.975KVd1O-lkp@intel.com/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 > Reported-by: Dan Carpenter > > smatch warnings: > kernel/trace/trace_events_hist.c:6174 event_hist_trigger_parse() error: we previously assumed 'glob' could be null (see line 6166) > > vim +/glob +6174 kernel/trace/trace_events_hist.c > > 9ec5a7d16899ed Tom Zanussi 2022-01-10 6149 static int event_hist_trigger_parse(struct event_command *cmd_ops, > 7ef224d1d0e3a1 Tom Zanussi 2016-03-03 6150 struct trace_event_file *file, > 7ef224d1d0e3a1 Tom Zanussi 2016-03-03 6151 char *glob, char *cmd, char *param) > 7ef224d1d0e3a1 Tom Zanussi 2016-03-03 6152 { > 7ef224d1d0e3a1 Tom Zanussi 2016-03-03 6153 unsigned int hist_trigger_bits = TRACING_MAP_BITS_DEFAULT; > 7ef224d1d0e3a1 Tom Zanussi 2016-03-03 6154 struct event_trigger_data *trigger_data; > 7ef224d1d0e3a1 Tom Zanussi 2016-03-03 6155 struct hist_trigger_attrs *attrs; > 7ef224d1d0e3a1 Tom Zanussi 2016-03-03 6156 struct event_trigger_ops *trigger_ops; > 7ef224d1d0e3a1 Tom Zanussi 2016-03-03 6157 struct hist_trigger_data *hist_data; > 4b147936fa5096 Tom Zanussi 2018-01-15 6158 struct synth_event *se; > 4b147936fa5096 Tom Zanussi 2018-01-15 6159 const char *se_name; > 30350d65ac5676 Tom Zanussi 2018-01-15 6160 bool remove = false; > c5eac6ee8bc5d3 Kalesh Singh 2021-10-25 6161 char *trigger, *p, *start; > 7ef224d1d0e3a1 Tom Zanussi 2016-03-03 6162 int ret = 0; > 7ef224d1d0e3a1 Tom Zanussi 2016-03-03 6163 > 0e2b81f7b52a1c Masami Hiramatsu 2018-11-05 6164 lockdep_assert_held(&event_mutex); > 0e2b81f7b52a1c Masami Hiramatsu 2018-11-05 6165 > f404da6e1d46ce Tom Zanussi 2018-01-15 @6166 if (glob && strlen(glob)) { I just reviewed the code, and it looks like the logic should keep glob from ever being NULL. I guess the solution could simply be to remove glob here, and perhaps add: WARN_ON(!glob); -- Steve > > Check for NULL > > f404da6e1d46ce Tom Zanussi 2018-01-15 6167 hist_err_clear(); > a1a05bb40e229d Tom Zanussi 2019-03-31 6168 last_cmd_set(file, param); > f404da6e1d46ce Tom Zanussi 2018-01-15 6169 } > f404da6e1d46ce Tom Zanussi 2018-01-15 6170 > 7ef224d1d0e3a1 Tom Zanussi 2016-03-03 6171 if (!param) > 7ef224d1d0e3a1 Tom Zanussi 2016-03-03 6172 return -EINVAL; > 7ef224d1d0e3a1 Tom Zanussi 2016-03-03 6173 > 30350d65ac5676 Tom Zanussi 2018-01-15 @6174 if (glob[0] == '!') > > Unchecked dereference > > 30350d65ac5676 Tom Zanussi 2018-01-15 6175 remove = true; > 30350d65ac5676 Tom Zanussi 2018-01-15 6176 > > --- > 0-DAY CI Kernel Test Service, Intel Corporation > https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org