skbuff: bad partial csum: csum=65535/65535 len=0 skbuff: bad partial csum: csum=65535/65535 len=0 INFO: task syz-executor3:15175 blocked for more than 140 seconds. Not tainted 4.18.0-rc3-next-20180706+ #1 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor3 D20160 15175 17997 0x00000004 Call Trace: context_switch kernel/sched/core.c:2853 [inline] __schedule+0x87c/0x1ed0 kernel/sched/core.c:3501 schedule+0xfb/0x450 kernel/sched/core.c:3545 io_schedule+0x1c/0x70 kernel/sched/core.c:5168 wait_on_page_bit_common+0x4ff/0x7a0 mm/filemap.c:1079 wait_on_page_bit mm/filemap.c:1112 [inline] wait_on_page_locked include/linux/pagemap.h:530 [inline] wait_on_page_read mm/filemap.c:2668 [inline] do_read_cache_page+0x97a/0x13c0 mm/filemap.c:2707 read_cache_page_gfp+0x6f/0x90 mm/filemap.c:2810 btrfs_read_disk_super fs/btrfs/volumes.c:1190 [inline] btrfs_scan_one_device+0x274/0xbf0 fs/btrfs/volumes.c:1244 btrfs_mount_root+0xd12/0x1eb0 fs/btrfs/super.c:1569 legacy_get_tree+0x118/0x440 fs/fs_context.c:659 vfs_get_tree+0x1cb/0x5c0 fs/super.c:1751 vfs_kern_mount.part.36+0x119/0x190 fs/namespace.c:3191 vfs_kern_mount+0x4a/0x70 fs/namespace.c:3171 btrfs_mount+0x4b7/0x217c fs/btrfs/super.c:1671 legacy_get_tree+0x118/0x440 fs/fs_context.c:659 vfs_get_tree+0x1cb/0x5c0 fs/super.c:1751 do_new_mount fs/namespace.c:2567 [inline] do_mount+0x6c1/0x1fb0 fs/namespace.c:2889 ksys_mount+0x12d/0x140 fs/namespace.c:3105 __do_sys_mount fs/namespace.c:3119 [inline] __se_sys_mount fs/namespace.c:3116 [inline] __x64_sys_mount+0xbe/0x150 fs/namespace.c:3116 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4585da Code: 05 5b 7d d4 01 48 89 04 24 e8 52 70 fb ff 48 8b ac 24 80 00 00 00 48 81 c4 88 00 00 00 c3 e8 dd 18 fd ff 0f 0b e8 d6 18 00 00 91 fd ff ff cc 64 48 8b 0c 25 f8 ff ff ff 48 3b 61 10 0f 86 37 RSP: 002b:00007f4013784a88 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f4013784b30 RCX: 00000000004585da RDX: 00007f4013784ad0 RSI: 0000000020000100 RDI: 00007f4013784af0 RBP: 0000000020000100 R08: 00007f4013784b30 R09: 00007f4013784ad0 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000015 R13: 0000000000000000 R14: 00000000004d3840 R15: 0000000000000005 INFO: lockdep is turned off. NMI backtrace for cpu 1 CPU: 1 PID: 898 Comm: khungtaskd Not tainted 4.18.0-rc3-next-20180706+ #1 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1c9/0x2b4 lib/dump_stack.c:113 nmi_cpu_backtrace.cold.5+0x19/0xce lib/nmi_backtrace.c:103 nmi_trigger_cpumask_backtrace+0x151/0x192 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace include/linux/nmi.h:143 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:204 [inline] watchdog+0xb39/0x10b0 kernel/hung_task.c:265 kthread+0x345/0x410 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:415 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 15211 Comm: loop3 Not tainted 4.18.0-rc3-next-20180706+ #1 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:check_memory_region+0xc0/0x1b0 mm/kasan/kasan.c:268 Code: 39 c3 0f 84 a8 00 00 00 48 83 38 00 74 ed 4c 8d 40 08 eb 09 48 83 c0 01 49 39 c0 74 0a 80 38 00 74 f2 48 85 c0 75 77 5b 41 5c <41> 5d 5d c3 41 bd 08 00 00 00 4d 89 c8 41 29 dd 4b 8d 5c 0d 00 eb RSP: 0018:ffff8801d7e16590 EFLAGS: 00000297 RAX: 0000000000000004 RBX: 0000000000000001 RCX: ffffffff8199fd4e RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff8801d7e16628 RBP: ffff8801d7e16598 R08: ffffed003afc2cc6 R09: ffffed003afc2cc5 R10: ffffed003afc2cc5 R11: 0000000000000003 R12: ffff8801d7e16948 R13: ffff8801d7e16628 R14: 0000000000000002 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8801dae00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffff600400 CR3: 00000001b18d8000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: kasan_check_read+0x11/0x20 mm/kasan/kasan.c:272 atomic_try_cmpxchg include/asm-generic/atomic-instrumented.h:72 [inline] atomic_fetch_add_unless include/linux/atomic.h:574 [inline] atomic_add_unless include/linux/atomic.h:591 [inline] page_ref_add_unless include/linux/page_ref.h:157 [inline] get_page_unless_zero include/linux/mm.h:511 [inline] page_cache_get_speculative include/linux/pagemap.h:186 [inline] find_get_entry+0x5ae/0x1120 mm/filemap.c:1411 find_lock_entry+0xe6/0x8c0 mm/filemap.c:1457 shmem_getpage_gfp+0x3cd/0x3ec0 mm/shmem.c:1610 shmem_getpage mm/shmem.c:132 [inline] shmem_file_read_iter+0x399/0x1090 mm/shmem.c:2433 call_read_iter include/linux/fs.h:1816 [inline] do_iter_readv_writev+0x790/0xa90 fs/read_write.c:678 do_iter_read+0x26e/0x650 fs/read_write.c:922 vfs_iter_read+0x77/0xb0 fs/read_write.c:936 lo_read_simple drivers/block/loop.c:350 [inline] do_req_filebacked drivers/block/loop.c:615 [inline] loop_handle_cmd drivers/block/loop.c:1786 [inline] loop_queue_work+0x9ce/0x3afc drivers/block/loop.c:1800 kthread_worker_fn+0x35f/0xa50 kernel/kthread.c:656 loop_kthread_worker_fn+0x51/0x60 drivers/block/loop.c:892 kthread+0x345/0x410 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:415 INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.347 msecs