INFO: task syz-executor.1:20318 blocked for more than 140 seconds. Not tainted 4.19.211-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D28888 20318 15866 0x00000004 Call Trace: context_switch kernel/sched/core.c:2828 [inline] __schedule+0x887/0x2040 kernel/sched/core.c:3517 schedule+0x8d/0x1b0 kernel/sched/core.c:3561 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:292 [inline] rwsem_down_read_failed+0x20a/0x390 kernel/locking/rwsem-xadd.c:309 call_rwsem_down_read_failed+0x14/0x30 arch/x86/lib/rwsem.S:94 __down_read arch/x86/include/asm/rwsem.h:83 [inline] down_read+0x44/0x80 kernel/locking/rwsem.c:26 __get_super.part.0+0x209/0x2e0 fs/super.c:698 __get_super include/linux/spinlock.h:329 [inline] get_super+0x2b/0x50 fs/super.c:727 fsync_bdev+0x14/0xc0 fs/block_dev.c:483 blkdev_flushbuf block/ioctl.c:436 [inline] blkdev_ioctl+0x912/0x1a80 block/ioctl.c:521 block_ioctl+0xe9/0x130 fs/block_dev.c:1906 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0xcdb/0x12e0 fs/ioctl.c:688 ksys_ioctl+0x9b/0xc0 fs/ioctl.c:705 __do_sys_ioctl fs/ioctl.c:712 [inline] __se_sys_ioctl fs/ioctl.c:710 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:710 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f7871d0e279 Code: Bad RIP value. RSP: 002b:00007f7870662168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f7871e21050 RCX: 00007f7871d0e279 RDX: 0000000000000000 RSI: 0000000000001261 RDI: 0000000000000003 RBP: 00007f7871d68189 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffe269f5e3f R14: 00007f7870662300 R15: 0000000000022000 Showing all locks held in the system: 1 lock held by khungtaskd/1570: #0: 0000000086da93ec (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x265 kernel/locking/lockdep.c:4441 1 lock held by in:imklog/7822: #0: 00000000f6e4a00c (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x26f/0x310 fs/file.c:767 ip6_tunnel: non-ECT from fc01:0000:0000:0000:0000:0000:0000:0000 with DS=0x62 2 locks held by agetty/7835: #0: 000000009ce3b691 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 #1: 00000000b97b31b6 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x217/0x1950 drivers/tty/n_tty.c:2154 1 lock held by syz-executor.1/20293: 1 lock held by syz-executor.1/20318: #0: 0000000079c960e3 (&type->s_umount_key#74){++++}, at: __get_super.part.0+0x209/0x2e0 fs/super.c:698 2 locks held by syz-executor.1/20762: #0: 000000000b3788e6 (&bdev->bd_fsfreeze_mutex){+.+.}, at: mount_bdev+0x90/0x3b0 fs/super.c:1125 #1: 0000000079c960e3 (&type->s_umount_key#74){++++}, at: grab_super+0xa2/0x350 fs/super.c:383 1 lock held by syz-executor.1/20763: #0: 0000000079c960e3 (&type->s_umount_key#74){++++}, at: __get_super.part.0+0x209/0x2e0 fs/super.c:698 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1570 Comm: khungtaskd Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1fc/0x2ef lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x63/0xa2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1a6/0x1f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline] watchdog+0x991/0xe60 kernel/hung_task.c:287 kthread+0x33f/0x460 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 7823 Comm: rs:main Q:Reg Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022 RIP: 0010:__sanitizer_cov_trace_pc+0x22/0x50 kernel/kcov.c:101 Code: 90 90 90 90 90 90 90 90 48 8b 34 24 65 48 8b 04 25 c0 df 01 00 65 8b 15 cc 59 9f 7e 81 e2 00 01 1f 00 75 2b 8b 90 60 13 00 00 <83> fa 02 75 20 48 8b 88 68 13 00 00 8b 80 64 13 00 00 48 8b 11 48 RSP: 0018:ffff888090f8f380 EFLAGS: 00000246 RAX: ffff8880a467c540 RBX: 0000000000000001 RCX: ffffffff816d11f8 RDX: 0000000000000000 RSI: ffffffff816d110d RDI: 0000000000000001 RBP: 00007f460cafa1cd R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000074071 R12: ffff888090f8f490 R13: 0000000000000000 R14: ffff88823b843080 R15: 0000000000000068 FS: 00007f460a0b6700(0000) GS:ffff8880ba100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f715be8a008 CR3: 0000000094c06000 CR4: 00000000003426e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 000000000000003b DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: bpf_jit_kallsyms_enabled include/linux/filter.h:949 [inline] bpf_prog_kallsyms_find kernel/bpf/core.c:509 [inline] is_bpf_text_address+0x6d/0x1b0 kernel/bpf/core.c:547 kernel_text_address kernel/extable.c:152 [inline] kernel_text_address+0xbd/0xf0 kernel/extable.c:122 __kernel_text_address+0x9/0x30 kernel/extable.c:107 unwind_get_return_address arch/x86/kernel/unwind_orc.c:297 [inline] unwind_get_return_address+0x51/0x90 arch/x86/kernel/unwind_orc.c:292 __save_stack_trace+0xaf/0x190 arch/x86/kernel/stacktrace.c:45 save_stack mm/kasan/kasan.c:448 [inline] set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc+0xeb/0x160 mm/kasan/kasan.c:553 kmem_cache_alloc+0x122/0x370 mm/slab.c:3559 kmem_cache_zalloc include/linux/slab.h:699 [inline] alloc_buffer_head+0x20/0x130 fs/buffer.c:3372 alloc_page_buffers+0x169/0x5c0 fs/buffer.c:830 create_empty_buffers+0x2c/0x760 fs/buffer.c:1528 create_page_buffers+0x212/0x350 fs/buffer.c:1645 __block_write_begin_int+0x22b/0x17b0 fs/buffer.c:1957 ext4_da_write_begin+0x4e1/0x10e0 fs/ext4/inode.c:3109 generic_perform_write+0x1f8/0x4d0 mm/filemap.c:3170 __generic_file_write_iter+0x24b/0x610 mm/filemap.c:3295 ext4_file_write_iter+0x2fe/0xf20 fs/ext4/file.c:272 call_write_iter include/linux/fs.h:1821 [inline] new_sync_write fs/read_write.c:474 [inline] __vfs_write+0x51b/0x770 fs/read_write.c:487 vfs_write+0x1f3/0x540 fs/read_write.c:549 ksys_write+0x12b/0x2a0 fs/read_write.c:599 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f460cafa1cd Code: c2 20 00 00 75 10 b8 01 00 00 00 0f 05 48 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 ae fc ff ff 48 89 04 24 b8 01 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 f7 fc ff ff 48 89 d0 48 83 c4 08 48 3d 01 RSP: 002b:00007f460a0b5590 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f4600025040 RCX: 00007f460cafa1cd RDX: 000000000000038e RSI: 00007f4600025040 RDI: 0000000000000008 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 00007f4600024dc0 R13: 00007f460a0b55b0 R14: 000055dbc39cf440 R15: 000000000000038e