INFO: task syz-executor0:24875 blocked for more than 140 seconds. Not tainted 4.18.0-rc5+ #28 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor0 D60856 24875 4625 0x00000004 Call Trace: context_switch kernel/sched/core.c:2857 [inline] __schedule+0x652/0x780 kernel/sched/core.c:3507 schedule+0x1cc/0x300 kernel/sched/core.c:3551 __rwsem_down_write_failed_common+0x807/0x1480 kernel/locking/rwsem-xadd.c:566 rwsem_down_write_failed+0x2c/0x30 kernel/locking/rwsem-xadd.c:595 call_rwsem_down_write_failed+0x17/0x30 arch/x86/lib/rwsem.S:117 __down_write arch/x86/include/asm/rwsem.h:142 [inline] down_write+0x5e/0xc0 kernel/locking/rwsem.c:72 grab_super+0xdd/0x390 fs/super.c:380 sget_userns+0x47f/0x1950 fs/super.c:508 kernfs_mount_ns+0x23b/0xea0 fs/kernfs/mount.c:321 kernfs_mount include/linux/kernfs.h:543 [inline] cgroup_do_mount+0x157/0x970 kernel/cgroup/cgroup.c:2000 cgroup_mount+0x1361/0x15c0 kernel/cgroup/cgroup.c:2064 mount_fs+0x29b/0x780 fs/super.c:1277 vfs_kern_mount+0x222/0x990 fs/namespace.c:1037 do_new_mount fs/namespace.c:2518 [inline] do_mount+0xd30/0x5310 fs/namespace.c:2848 ksys_mount+0x32e/0x3d0 fs/namespace.c:3064 __do_sys_mount fs/namespace.c:3078 [inline] __se_sys_mount fs/namespace.c:3075 [inline] __x64_sys_mount+0x157/0x1c0 fs/namespace.c:3075 do_syscall_64+0x15b/0x230 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x63/0xe7 RIP: 0033:0x455ab9 Code: Bad RIP value. RSP: 002b:00007feb33c0ac68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007feb33c0b6d4 RCX: 0000000000455ab9 RDX: 0000000020000080 RSI: 0000000020000040 RDI: 0000000020000000 RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000013 R13: 00000000004c01fb R14: 00000000004cfe38 R15: 0000000000000007 NMI backtrace for cpu 1 CPU: 1 PID: 809 Comm: khungtaskd Not tainted 4.18.0-rc5+ #28 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+0x185/0x1e0 lib/dump_stack.c:113 nmi_cpu_backtrace lib/nmi_backtrace.c:103 [inline] nmi_trigger_cpumask_backtrace+0x26f/0x4e0 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x2c/0x40 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace+0x2b/0x30 include/linux/nmi.h:138 check_hung_uninterruptible_tasks kernel/hung_task.c:196 [inline] watchdog+0x1107/0x1130 kernel/hung_task.c:252 kthread+0x473/0x4b0 kernel/kthread.c:247 ret_from_fork+0x35/0x40 arch/x86/entry/entry_64.S:415 Sending NMI from CPU 1 to CPUs 0: ------------[ cut here ]------------ kernel BUG at mm/kmsan/kmsan_entry.c:81! invalid opcode: 0000 [#1] SMP PTI CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.18.0-rc5+ #28 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:kmsan_nmi_enter+0x42/0x70 mm/kmsan/kmsan_entry.c:80 Code: 00 74 27 65 8b 04 25 80 90 03 00 83 c0 01 83 f8 08 7d 27 65 89 04 25 80 90 03 00 65 c6 04 25 15 6e 0b 00 ff c3 0f 0b 90 eb fe <0f> 0b 66 90 66 2e 0f 1f 84 00 00 00 00 00 eb fe 0f 0b 66 90 66 2e RSP: 0018:fffffe000000eea8 EFLAGS: 00010046 RAX: 0000000080000000 RBX: 0000000000000001 RCX: 00000000c0000101 RDX: 00000000ffff8802 RSI: ffffffff8a40136c RDI: ffffea0000439620 RBP: fffffe000000eef9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 000000018b898000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff88021fc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c42ccf9010 CR3: 000000018b898000 CR4: 00000000001406f0 DR0: 0000000020000000 DR1: 0000000020000000 DR2: 0000000020000000 DR3: 0000000020000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Call Trace: Modules linked in: Dumping ftrace buffer: (ftrace buffer empty) ---[ end trace b4ffe13aadce8e91 ]--- RIP: 0010:kmsan_nmi_enter+0x42/0x70 mm/kmsan/kmsan_entry.c:80 Code: 00 74 27 65 8b 04 25 80 90 03 00 83 c0 01 83 f8 08 7d 27 65 89 04 25 80 90 03 00 65 c6 04 25 15 6e 0b 00 ff c3 0f 0b 90 eb fe <0f> 0b 66 90 66 2e 0f 1f 84 00 00 00 00 00 eb fe 0f 0b 66 90 66 2e RSP: 0018:fffffe000000eea8 EFLAGS: 00010046 RAX: 0000000080000000 RBX: 0000000000000001 RCX: 00000000c0000101 RDX: 00000000ffff8802 RSI: ffffffff8a40136c RDI: ffffea0000439620 RBP: fffffe000000eef9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 000000018b898000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff88021fc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c42ccf9010 CR3: 000000018b898000 CR4: 00000000001406f0 DR0: 0000000020000000 DR1: 0000000020000000 DR2: 0000000020000000 DR3: 0000000020000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600