netlink: 12 bytes leftover after parsing attributes in process `syz-executor.4'. netlink: 16 bytes leftover after parsing attributes in process `syz-executor.4'. INFO: task syz-executor.0:23917 blocked for more than 140 seconds. Not tainted 4.14.256-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D28912 23917 8012 0x00000004 Call Trace: context_switch kernel/sched/core.c:2811 [inline] __schedule+0x88b/0x1de0 kernel/sched/core.c:3387 schedule+0x8d/0x1b0 kernel/sched/core.c:3431 __rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:588 [inline] rwsem_down_write_failed+0x343/0x6d0 kernel/locking/rwsem-xadd.c:617 call_rwsem_down_write_failed+0x13/0x20 arch/x86/lib/rwsem.S:105 __down_write arch/x86/include/asm/rwsem.h:126 [inline] down_write+0x4f/0x90 kernel/locking/rwsem.c:56 grab_super+0x55/0x140 fs/super.c:373 sget_userns+0x2b1/0xc10 fs/super.c:504 sget+0xd1/0x110 fs/super.c:572 mount_bdev+0xcd/0x360 fs/super.c:1107 mount_fs+0x92/0x2a0 fs/super.c:1237 vfs_kern_mount.part.0+0x5b/0x470 fs/namespace.c:1046 vfs_kern_mount fs/namespace.c:1036 [inline] do_new_mount fs/namespace.c:2572 [inline] do_mount+0xe65/0x2a10 fs/namespace.c:2902 SYSC_mount fs/namespace.c:3118 [inline] SyS_mount+0xa8/0x120 fs/namespace.c:3095 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7f076f87cae9 RSP: 002b:00007f076e7d1188 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f076f990028 RCX: 00007f076f87cae9 RDX: 00000000200001c0 RSI: 0000000020000180 RDI: 0000000020000140 RBP: 00007f076f8d6ff7 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc4a1ebeaf R14: 00007f076e7d1300 R15: 0000000000022000 Showing all locks held in the system: 1 lock held by khungtaskd/1533: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4548 2 locks held by syz-executor.0/23917: #0: (&bdev->bd_fsfreeze_mutex){+.+.}, at: [] mount_bdev+0x71/0x360 fs/super.c:1101 #1: (&type->s_umount_key#106){+.+.}, at: [] grab_super+0x55/0x140 fs/super.c:373 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1533 Comm: khungtaskd Not tainted 4.14.256-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x281 lib/dump_stack.c:58 nmi_cpu_backtrace.cold+0x57/0x93 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x13a/0x180 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:140 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:195 [inline] watchdog+0x5b9/0xb40 kernel/hung_task.c:274 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 23902 Comm: syz-executor.0 Not tainted 4.14.256-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff88805fcb0440 task.stack: ffff888060b60000 RIP: 0010:__sanitizer_cov_trace_pc+0x15/0x50 kernel/kcov.c:65 RSP: 0018:ffff888060b67ab8 EFLAGS: 00000282 RAX: ffff88805fcb0440 RBX: ffff8880b1fe04e8 RCX: ffffc900084de000 RDX: 0000000080000000 RSI: ffffffff86fe3bd4 RDI: ffff8880b1fe04f0 RBP: 0000000001420848 R08: 0000000000000000 R09: 0000000000020012 R10: ffff88805fcb0cf0 R11: ffff88805fcb0440 R12: ffff88808cf83bb8 R13: ffff8880b1fe04e8 R14: dffffc0000000000 R15: 0000000000000002 FS: 00007f076e7f2700(0000) GS:ffff8880ba400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555556807848 CR3: 00000000ab86c000 CR4: 00000000003406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __read_once_size include/linux/compiler.h:185 [inline] radix_tree_deref_slot include/linux/radix-tree.h:238 [inline] find_get_entry+0x9c/0x630 mm/filemap.c:1357 pagecache_get_page+0x53/0xab0 mm/filemap.c:1465 find_or_create_page include/linux/pagemap.h:326 [inline] grow_dev_page fs/buffer.c:1004 [inline] grow_buffers fs/buffer.c:1077 [inline] __getblk_slow+0x1dd/0x7a0 fs/buffer.c:1104 __getblk_gfp fs/buffer.c:1383 [inline] __bread_gfp+0x206/0x2e0 fs/buffer.c:1428 sb_bread include/linux/buffer_head.h:309 [inline] vxfs_try_sb_magic+0xa1/0x3b0 fs/freevxfs/vxfs_super.c:163 vxfs_fill_super+0x41e/0x810 fs/freevxfs/vxfs_super.c:244 mount_bdev+0x2b3/0x360 fs/super.c:1134 mount_fs+0x92/0x2a0 fs/super.c:1237 vfs_kern_mount.part.0+0x5b/0x470 fs/namespace.c:1046 vfs_kern_mount fs/namespace.c:1036 [inline] do_new_mount fs/namespace.c:2572 [inline] do_mount+0xe65/0x2a10 fs/namespace.c:2902 SYSC_mount fs/namespace.c:3118 [inline] SyS_mount+0xa8/0x120 fs/namespace.c:3095 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7f076f87cae9 RSP: 002b:00007f076e7f2188 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f076f98ff60 RCX: 00007f076f87cae9 RDX: 00000000200001c0 RSI: 0000000020000180 RDI: 0000000020000140 RBP: 00007f076f8d6ff7 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc4a1ebeaf R14: 00007f076e7f2300 R15: 0000000000022000 Code: 29 00 e9 2c fe ff ff 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 65 48 8b 04 25 c0 7f 02 00 48 85 c0 74 1a 65 8b 15 3b 44 ad 7e <81> e2 00 01 1f 00 75 0b 8b 90 58 13 00 00 83 fa 01 74 01 c3 48 ---------------- Code disassembly (best guess): 0: 29 00 sub %eax,(%rax) 2: e9 2c fe ff ff jmpq 0xfffffe33 7: 90 nop 8: 90 nop 9: 90 nop a: 90 nop b: 90 nop c: 90 nop d: 90 nop e: 90 nop f: 90 nop 10: 90 nop 11: 90 nop 12: 90 nop 13: 90 nop 14: 90 nop 15: 90 nop 16: 65 48 8b 04 25 c0 7f mov %gs:0x27fc0,%rax 1d: 02 00 1f: 48 85 c0 test %rax,%rax 22: 74 1a je 0x3e 24: 65 8b 15 3b 44 ad 7e mov %gs:0x7ead443b(%rip),%edx # 0x7ead4466 * 2b: 81 e2 00 01 1f 00 and $0x1f0100,%edx <-- trapping instruction 31: 75 0b jne 0x3e 33: 8b 90 58 13 00 00 mov 0x1358(%rax),%edx 39: 83 fa 01 cmp $0x1,%edx 3c: 74 01 je 0x3f 3e: c3 retq 3f: 48 rex.W