bisecting fixing commit since a1b8638ba1320e6684aa98233c15255eb803fac7 building syzkaller on 6bfdbe8950b22b1c832478bd397754f3108df040 testing commit a1b8638ba1320e6684aa98233c15255eb803fac7 compiler: gcc (GCC) 8.4.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: a2bd2a7914d84f11d354c624287775dee6716e67bda7a3dc929d141adfda16a6 run #0: crashed: INFO: task hung in do_read_cache_page run #1: crashed: INFO: task hung in do_read_cache_page run #2: crashed: INFO: task hung in do_read_cache_page run #3: crashed: INFO: task hung in do_read_cache_page run #4: crashed: INFO: task hung in do_read_cache_page run #5: crashed: INFO: task hung in do_read_cache_page run #6: crashed: INFO: task hung in blkdev_put run #7: crashed: INFO: task hung in do_read_cache_page run #8: crashed: INFO: task hung in do_read_cache_page run #9: crashed: INFO: task hung in do_read_cache_page run #10: crashed: INFO: task hung in do_read_cache_page run #11: crashed: INFO: task hung in do_read_cache_page run #12: crashed: INFO: task hung in do_read_cache_page run #13: crashed: INFO: task hung in do_read_cache_page run #14: crashed: INFO: task hung in do_read_cache_page run #15: crashed: INFO: task hung in do_read_cache_page run #16: crashed: INFO: task hung in do_read_cache_page run #17: crashed: INFO: task hung in do_read_cache_page run #18: crashed: INFO: task hung in do_read_cache_page run #19: crashed: INFO: task hung in do_read_cache_page testing current HEAD 0885eacdc81f920c3e0554d5615e69a66504a28d testing commit 0885eacdc81f920c3e0554d5615e69a66504a28d compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: 39a161c21430394fd35f090c73775cc49adc9a45f2b39cc5038c26862d9fd256 all runs: crashed: INFO: task hung in do_read_cache_folio revisions tested: 2, total time: 25m10.128865682s (build: 11m3.708832564s, test: 13m0.216109491s) the crash still happens on HEAD commit msg: Merge tag 'nfsd-5.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux crash: INFO: task hung in do_read_cache_folio INFO: task udevd:2716 blocked for more than 143 seconds. Not tainted 5.19.0-rc1-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:26640 pid: 2716 ppid: 2153 flags:0x00004004 Call Trace: __schedule+0xd95/0x27f0 schedule+0xd2/0x1f0 io_schedule+0xba/0x130 folio_wait_bit_common+0x387/0x7d0 do_read_cache_folio+0x3be/0x5b0 read_cache_page+0x48/0x1f0 read_part_sector+0xe0/0x690 adfspart_check_ICS+0x96/0x610 bdev_disk_changed+0x497/0xd20 blkdev_get_whole+0x141/0x270 blkdev_get_by_dev.part.0+0x4fa/0xa50 blkdev_open+0xde/0x240 do_dentry_open+0x414/0xfe0 path_openat+0x9cf/0x2360 do_filp_open+0x199/0x3d0 do_sys_openat2+0x11e/0x3f0 __x64_sys_openat+0x11b/0x1d0 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 RIP: 0033:0x7f0338525697 RSP: 002b:00007ffd3602d340 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000564266451850 RCX: 00007f0338525697 RDX: 00000000000a0800 RSI: 000056426645fa90 RDI: 00000000ffffff9c RBP: 000056426645fa90 R08: 0000000000000001 R09: 00007ffd3608d080 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000000a0800 R13: 0000564266449850 R14: 0000000000000001 R15: 00005642664332c0 INFO: task syz-executor.0:2730 blocked for more than 143 seconds. Not tainted 5.19.0-rc1-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.0 state:D stack:27224 pid: 2730 ppid: 2711 flags:0x00000004 Call Trace: __schedule+0xd95/0x27f0 schedule+0xd2/0x1f0 schedule_preempt_disabled+0xf/0x20 __mutex_lock+0xa70/0x1350 blkdev_put+0x9a/0x670 blkdev_close+0x5f/0x90 __fput+0x1f5/0x8c0 task_work_run+0xc0/0x160 exit_to_user_mode_prepare+0x1e0/0x1f0 syscall_exit_to_user_mode+0x16/0x40 do_syscall_64+0x42/0x80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 RIP: 0033:0x418c1b RSP: 002b:00007fff83db8c00 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000418c1b RDX: 00000000000003e7 RSI: 0000001b2d2200bc RDI: 0000000000000004 RBP: 0000000000000005 R08: 0000000000000000 R09: 0000001b2d2200c4 R10: 00007fff83df6090 R11: 0000000000000293 R12: 000000000055d9a0 R13: 000000000055d9a0 R14: 000000000055cf20 R15: 000000000055cf20 INFO: task syz-executor.0:2731 blocked for more than 143 seconds. Not tainted 5.19.0-rc1-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.0 state:D stack:27512 pid: 2731 ppid: 2711 flags:0x00004006 Call Trace: __schedule+0xd95/0x27f0 schedule+0xd2/0x1f0 schedule_preempt_disabled+0xf/0x20 __mutex_lock+0xa70/0x1350 blkdev_put+0x9a/0x670 blkdev_close+0x5f/0x90 __fput+0x1f5/0x8c0 task_work_run+0xc0/0x160 get_signal+0x19b/0x2060 arch_do_signal_or_restart+0x88/0x1b90 exit_to_user_mode_prepare+0x14a/0x1f0 syscall_exit_to_user_mode+0x16/0x40 do_syscall_64+0x42/0x80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 RIP: 0033:0x465ad9 RSP: 002b:00007f0e5b82c188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: fffffffffffffe00 RBX: 000000000055cf20 RCX: 0000000000465ad9 RDX: ffffffffffffffff RSI: 000000000000ab03 RDI: 0000000000000003 RBP: 00000000004af756 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000055cf20 R13: 00007fff83db8b9f R14: 00007f0e5b82c300 R15: 0000000000022000 Showing all locks held in the system: 1 lock held by khungtaskd/28: #0: ffffffff8a1bbfe0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x28c 2 locks held by getty/2313: #0: ffff88810d1ff098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x1f/0x70 #1: ffffc900016c32e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xb21/0x1050 1 lock held by udevd/2716: #0: ffff888109821918 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev.part.0+0x78/0xa50 1 lock held by syz-executor.0/2730: #0: ffff888109821918 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0x9a/0x670 1 lock held by syz-executor.0/2731: #0: ffff888109821918 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0x9a/0x670 =============================================