INFO: task syz-executor.2:7404 blocked for more than 140 seconds. Not tainted 4.9.189+ #3 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D28424 7404 7391 0x00000004 0000000000000087 ffff8801104a97c0 ffff8801c6e9dd80 ffff8801db621000 ffff8801d1188000 ffff8801db621018 ffff8801a31b7950 ffffffff82818d1e ffff8801a31b78b8 1ffffffff063fba8 0000000000000000 ffff8801db6218f0 Call Trace: [<00000000e4cac64a>] schedule+0x92/0x1c0 kernel/sched/core.c:3546 [<00000000b2a2c9fe>] __rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:549 [inline] [<00000000b2a2c9fe>] rwsem_down_write_failed+0x3a3/0x750 kernel/locking/rwsem-xadd.c:578 [<0000000067146471>] call_rwsem_down_write_failed+0x17/0x30 arch/x86/lib/rwsem.S:105 [<00000000848a4d27>] __down_write arch/x86/include/asm/rwsem.h:125 [inline] [<00000000848a4d27>] down_write+0x5c/0xa0 kernel/locking/rwsem.c:54 [<0000000023f8875d>] grab_super+0x5e/0x150 fs/super.c:374 [<000000005f7997e9>] sget_userns+0x2b3/0xc50 fs/super.c:501 [<000000001b3d174c>] sget+0xd6/0x120 fs/super.c:569 [<0000000007d8e926>] mount_bdev+0xd5/0x360 fs/super.c:1083 [<00000000687c9994>] ext4_mount+0x35/0x40 fs/ext4/super.c:5627 [<0000000016d920d0>] mount_fs+0x27c/0x380 fs/super.c:1216 [<00000000ff24937e>] vfs_kern_mount.part.0+0xcd/0x4c0 fs/namespace.c:1000 [<000000006c92b620>] vfs_kern_mount fs/namespace.c:982 [inline] [<000000006c92b620>] do_new_mount fs/namespace.c:2549 [inline] [<000000006c92b620>] do_mount+0x3c4/0x2970 fs/namespace.c:2871 [<0000000087b08cab>] SYSC_mount fs/namespace.c:3087 [inline] [<0000000087b08cab>] SyS_mount+0xab/0x120 fs/namespace.c:3064 [<000000006b15ae48>] do_syscall_64+0x1ad/0x5c0 arch/x86/entry/common.c:288 [<00000000d766638e>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb Showing all locks held in the system: 2 locks held by khungtaskd/24: #0: (rcu_read_lock){......}, at: [<000000003c7e7d35>] check_hung_uninterruptible_tasks kernel/hung_task.c:169 [inline] #0: (rcu_read_lock){......}, at: [<000000003c7e7d35>] watchdog+0x14b/0xaf0 kernel/hung_task.c:263 #1: (tasklist_lock){.+.+..}, at: [<000000007280c08f>] debug_show_all_locks+0x7f/0x21f kernel/locking/lockdep.c:4336 1 lock held by rsyslogd/1895: #0: (&f->f_pos_lock){+.+.+.}, at: [<000000002f59267f>] __fdget_pos+0xa8/0xd0 fs/file.c:782 2 locks held by getty/2022: #0: (&tty->ldisc_sem){++++++}, at: [<00000000d0ea184c>] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377 #1: (&ldata->atomic_read_lock){+.+...}, at: [<00000000670c3b61>] n_tty_read+0x1fe/0x1820 drivers/tty/n_tty.c:2156 2 locks held by syz-executor.2/7404: #0: (&bdev->bd_fsfreeze_mutex){+.+.+.}, at: [<00000000c88c1729>] mount_bdev+0x76/0x360 fs/super.c:1077 #1: (&type->s_umount_key#32){++++++}, at: [<0000000023f8875d>] grab_super+0x5e/0x150 fs/super.c:374 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 24 Comm: khungtaskd Not tainted 4.9.189+ #3 ffff8801d98d7cc8 ffffffff81b65c01 0000000000000001 0000000000000000 0000000000000001 ffffffff81099a01 dffffc0000000000 ffff8801d98d7d00 ffffffff81b70e9c 0000000000000001 0000000000000000 0000000000000001 Call Trace: [<00000000acc1100f>] __dump_stack lib/dump_stack.c:15 [inline] [<00000000acc1100f>] dump_stack+0xc1/0x120 lib/dump_stack.c:51 [<00000000f46eb175>] nmi_cpu_backtrace.cold+0x47/0x87 lib/nmi_backtrace.c:99 [<00000000d3b54162>] nmi_trigger_cpumask_backtrace+0x124/0x155 lib/nmi_backtrace.c:60 [<000000005ddba64f>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37 [<00000000f44a4a89>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline] [<00000000f44a4a89>] check_hung_task kernel/hung_task.c:126 [inline] [<00000000f44a4a89>] check_hung_uninterruptible_tasks kernel/hung_task.c:183 [inline] [<00000000f44a4a89>] watchdog+0x670/0xaf0 kernel/hung_task.c:263 [<00000000ef350e2e>] kthread+0x278/0x310 kernel/kthread.c:211 [<00000000b9337a7a>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:375 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 7391 Comm: syz-executor.2 Not tainted 4.9.189+ #3 task: 00000000c2ca1424 task.stack: 0000000091e32808 RIP: 0010:[] c [<00000000a1f96c12>] debug_smp_processor_id+0x1c/0x20 lib/smp_processor_id.c:57 RSP: 0018:ffff8801c7d8f648 EFLAGS: 00000092 RAX: 0000000000000000 RBX: 000060fe24614888 RCX: ffffc90001776000 RDX: 0000000000040000 RSI: ffffffff81bcc25c RDI: ffffffff82b45240 RBP: ffff8801c7d8f648 R08: 0000000000000002 R09: 0000000000000000 R10: 0000000000000000 R11: ffffffff81204b70 R12: ffffffff830c31e0 R13: ffffffff830d5a20 R14: ffff8801c7d8f720 R15: 0000000000000000 FS: 00007fd495aa1700(0000) GS:ffff8801db600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000015b4000 CR3: 000000010aec2000 CR4: 00000000001606b0 DR0: 0000000020000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Stack: ffff8801c7d8f748c ffffffff81204c92c ffff8801a98f8000c ffff8801c7d8f800c ffffffff8120d360c 00000002812050a0c 000e001800000000c ffffffff830d5a38c ffffffff0000000dc 1ffff10038fb1ed4c 1ffff10038fb1ee3c 0000000041b58ab3c Call Trace: [<00000000cf8f0112>] perf_trace_lock_acquire+0x122/0x530 include/trace/events/lock.h:12 [<000000002e3e53df>] trace_lock_acquire include/trace/events/lock.h:12 [inline] [<000000002e3e53df>] lock_acquire+0x29a/0x3d0 kernel/locking/lockdep.c:3755 [<000000007ad53fbb>] rcu_lock_acquire include/linux/rcupdate.h:491 [inline] [<000000007ad53fbb>] rcu_read_lock include/linux/rcupdate.h:873 [inline] [<000000007ad53fbb>] find_get_entry+0x4a/0x510 mm/filemap.c:1217 [<000000006feaaa9a>] pagecache_get_page+0x4a/0x740 mm/filemap.c:1331 [<0000000032f5a99e>] find_get_page_flags include/linux/pagemap.h:265 [inline] [<0000000032f5a99e>] __find_get_block_slow+0xc2/0x370 fs/buffer.c:213 [<00000000fd642cb9>] __find_get_block+0x299/0x4c0 fs/buffer.c:1361 [<000000006067962b>] __getblk_slow fs/buffer.c:1102 [inline] [<000000006067962b>] __getblk_gfp+0x182/0x700 fs/buffer.c:1387 [<000000006960ddac>] __bread_gfp+0x2e/0x1f0 fs/buffer.c:1421 [<00000000dae8661d>] sb_bread_unmovable include/linux/buffer_head.h:306 [inline] [<00000000dae8661d>] ext4_fill_super+0x55c/0xb7a0 fs/ext4/super.c:3444 [<00000000ea2c0d35>] mount_bdev+0x2b8/0x360 fs/super.c:1110 [<00000000687c9994>] ext4_mount+0x35/0x40 fs/ext4/super.c:5627 [<0000000016d920d0>] mount_fs+0x27c/0x380 fs/super.c:1216 [<00000000ff24937e>] vfs_kern_mount.part.0+0xcd/0x4c0 fs/namespace.c:1000 [<000000006c92b620>] vfs_kern_mount fs/namespace.c:982 [inline] [<000000006c92b620>] do_new_mount fs/namespace.c:2549 [inline] [<000000006c92b620>] do_mount+0x3c4/0x2970 fs/namespace.c:2871 [<0000000087b08cab>] SYSC_mount fs/namespace.c:3087 [inline] [<0000000087b08cab>] SyS_mount+0xab/0x120 fs/namespace.c:3064 [<000000006b15ae48>] do_syscall_64+0x1ad/0x5c0 arch/x86/entry/common.c:288 [<00000000d766638e>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb Code: c9b c20 c93 cff c4c c8b c45 cd0 ce9 cac cfe cff cff c66 c90 c55 c48 c89 ce5 ce8 c47 c5f c75 cff c48 cc7 cc6 c00 c52 cb4 c82 c48 cc7 cc7 c40 c52 cb4 c82 ce8 ce4 cfd cff cff c<5d> cc3 c66 c90 c55 c48 c89 ce5 c41 c54 c49 c89 cfc ce8 c22 c5f c75 cff c4c c89 ce6 c