bisecting fixing commit since 2762b48e9611529239da2e68cba908dbbec9805f
building syzkaller on 63631df1539816bc62c7be40779c5f3e23b23b2f
testing commit 2762b48e9611529239da2e68cba908dbbec9805f with gcc (GCC) 8.4.1 20210217
kernel signature: f43fb63deec456faf0f24bdddd9c7ce8bbcb163ac21d4c0889d425e6f8331fcb
run #0: crashed: INFO: task hung in grab_super
run #1: crashed: INFO: task hung in grab_super
run #2: crashed: INFO: task hung in grab_super
run #3: crashed: INFO: task hung in grab_super
run #4: crashed: INFO: task hung in grab_super
run #5: crashed: INFO: task hung in grab_super
run #6: crashed: INFO: task hung in grab_super
run #7: crashed: INFO: task hung in grab_super
run #8: crashed: INFO: task hung in grab_super
run #9: crashed: INFO: task hung in grab_super
run #10: crashed: INFO: task hung in grab_super
run #11: crashed: INFO: task hung in grab_super
run #12: crashed: INFO: task hung in grab_super
run #13: crashed: INFO: task hung in grab_super
run #14: crashed: INFO: task hung in grab_super
run #15: crashed: INFO: task hung in grab_super
run #16: crashed: INFO: task hung in grab_super
run #17: crashed: INFO: task hung in grab_super
run #18: crashed: no output from test machine
run #19: crashed: no output from test machine
testing current HEAD 29c52025152bab4c557d8174da58f1a4c8e70438
testing commit 29c52025152bab4c557d8174da58f1a4c8e70438 with gcc (GCC) 8.4.1 20210217
kernel signature: 94aacb43782e625dd295cc483feca7f3692395f30b08c195dcf313bd4422f656
run #0: crashed: INFO: task hung in grab_super
run #1: crashed: INFO: task hung in grab_super
run #2: crashed: INFO: task hung in grab_super
run #3: crashed: INFO: task hung in grab_super
run #4: crashed: INFO: task hung in grab_super
run #5: crashed: INFO: task hung in grab_super
run #6: crashed: no output from test machine
run #7: crashed: no output from test machine
run #8: crashed: no output from test machine
run #9: crashed: no output from test machine
revisions tested: 2, total time: 31m17.77929749s (build: 14m9.529838478s, test: 16m16.284649416s)
the crash still happens on HEAD
commit msg: Linux 4.14.221
crash: no output from test machine