bisecting fixing commit since f0ec9c65a8d67e50a16745e62a336355ddf5d03e
building syzkaller on cb58b3b231a677b1a6c89cd2af59e4fab10f9144
testing commit f0ec9c65a8d67e50a16745e62a336355ddf5d03e
compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2
kernel signature: 4e53b2a541c6002fc3203877ad6b96d2775ff16517fea93cb77aac0d32ce594a
run #0: crashed: INFO: task hung in kernfs_fop_readdir
run #1: crashed: INFO: task hung in kernfs_dop_revalidate
run #2: OK
run #3: OK
run #4: OK
run #5: OK
run #6: OK
run #7: OK
run #8: OK
run #9: OK
run #10: OK
run #11: OK
run #12: OK
run #13: OK
run #14: OK
run #15: OK
run #16: OK
run #17: OK
run #18: crashed: INFO: task hung in kernfs_dop_revalidate
run #19: OK
reproducer seems to be flaky
testing current HEAD ff6992735ade75aae3e35d16b17da1008d753d28
testing commit ff6992735ade75aae3e35d16b17da1008d753d28
compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2
kernel signature: ba829818f1e72f9bf8bfe8cdee967b19cb6fb7b314379112cff409f0eba0f347
run #0: crashed: SYZFATAL: executor failed NUM times: executor NUM: exit status NUM
run #1: crashed: INFO: task hung in kernfs_iop_getattr
run #2: crashed: INFO: task hung in kernfs_fop_readdir
run #3: OK
run #4: OK
run #5: OK
run #6: OK
run #7: OK
run #8: OK
run #9: OK
run #10: OK
run #11: OK
run #12: OK
run #13: OK
run #14: OK
run #15: OK
run #16: OK
run #17: OK
run #18: OK
run #19: OK
Reproducer flagged being flaky
revisions tested: 2, total time: 32m36.074845404s (build: 13m43.550916651s, test: 18m8.529768519s)
the crash still happens on HEAD
commit msg: Linux 5.19-rc7
crash: INFO: task hung in kernfs_fop_readdir
INFO: task udevd:2973 blocked for more than 146 seconds.
      Not tainted 5.19.0-rc7-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:udevd           state:D stack:26768 pid: 2973 ppid:     1 flags:0x00000000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5146 [inline]
 __schedule+0x9cd/0x4b20 kernel/sched/core.c:6458
 schedule+0xd2/0x1f0 kernel/sched/core.c:6530
 rwsem_down_read_slowpath+0x5b9/0xb00 kernel/locking/rwsem.c:1077
 __down_read_common kernel/locking/rwsem.c:1242 [inline]
 __down_read kernel/locking/rwsem.c:1251 [inline]
 down_read+0xe2/0x440 kernel/locking/rwsem.c:1491
 kernfs_fop_readdir+0x170/0x820 fs/kernfs/dir.c:1748
 iterate_dir+0x47b/0x6c0 fs/readdir.c:65
 __do_sys_getdents64 fs/readdir.c:369 [inline]
 __se_sys_getdents64 fs/readdir.c:354 [inline]
 __x64_sys_getdents64+0x124/0x240 fs/readdir.c:354
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f560ef6b097
RSP: 002b:00007ffcbcc26f98 EFLAGS: 00000293 ORIG_RAX: 00000000000000d9
RAX: ffffffffffffffda RBX: 00005636502470e0 RCX: 00007f560ef6b097
RDX: 0000000000008000 RSI: 0000563650247110 RDI: 000000000000000e
RBP: 0000563650247110 R08: 00000000000000f8 R09: 00005636501570a0
R10: 0000000010000000 R11: 0000000000000293 R12: fffffffffffffe68
R13: 00005636502470e4 R14: 0000000000000002 R15: 0000000000000000
 </TASK>
INFO: task syz-executor.1:4007 blocked for more than 151 seconds.
      Not tainted 5.19.0-rc7-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.1  state:D stack:25456 pid: 4007 ppid:     1 flags:0x00000004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5146 [inline]
 __schedule+0x9cd/0x4b20 kernel/sched/core.c:6458
 schedule+0xd2/0x1f0 kernel/sched/core.c:6530
 rwsem_down_read_slowpath+0x5b9/0xb00 kernel/locking/rwsem.c:1077
 __down_read_common kernel/locking/rwsem.c:1242 [inline]
 __down_read kernel/locking/rwsem.c:1251 [inline]
 down_read+0xe2/0x440 kernel/locking/rwsem.c:1491
 kernfs_iop_permission+0xa1/0x110 fs/kernfs/inode.c:290
 do_inode_permission fs/namei.c:458 [inline]
 inode_permission.part.0+0x2ca/0x470 fs/namei.c:525
 inode_permission fs/namei.c:506 [inline]
 may_lookup fs/namei.c:1731 [inline]
 link_path_walk.part.0+0x618/0xb80 fs/namei.c:2283
 link_path_walk fs/namei.c:2266 [inline]
 path_openat+0x204/0x2360 fs/namei.c:3649
 do_filp_open+0x199/0x3d0 fs/namei.c:3680
 do_sys_openat2+0x11e/0x3f0 fs/open.c:1278