INFO: task hung in ubi_detach_mtd

INFO: task hung in ubi_detach_mtd_dev
Status: fixed on 2020/11/16 12:12
Reported-by: syzbot+853639d0cb16c31c7a14@syzkaller.appspotmail.com
Fix commit: d005f8c6 ubi: check kthread_should_stop() after the setting of task state
First crash: 340d, last: 250d

Cause bisection: failed (bisect log)

Fix bisection: failed (bisect log)
similar bugs (3):
Kernel	Title	Repro	Fix bisect	Count	Last	Reported	Patched	Status
linux-4.19	INFO: task hung in ubi_detach_mtd_dev (2)	syz	error	1	194d	194d	0/1	upstream: reported syz repro on 2020/07/15 16:30
linux-4.14	INFO: task hung in ubi_detach_mtd_dev			6	205d	297d	0/1	auto-closed as invalid on 2020/11/01 05:07
linux-4.19	INFO: task hung in ubi_detach_mtd_dev			1	335d	335d	0/1	auto-closed as invalid on 2020/06/24 16:43
Sample crash report:
INFO: task syz-executor.2:11136 blocked for more than 143 seconds.
      Not tainted 5.7.0-rc2-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.2  D28560 11136   7038 0x00004004
Call Trace:
 context_switch kernel/sched/core.c:3372 [inline]
 __schedule+0x805/0xc90 kernel/sched/core.c:4088
 schedule+0x188/0x220 kernel/sched/core.c:4163
 schedule_timeout+0x43/0x250 kernel/time/timer.c:1874
 mark_held_locks kernel/locking/lockdep.c:3628 [inline]
 __trace_hardirqs_on_caller kernel/locking/lockdep.c:3657 [inline]
 lockdep_hardirqs_on+0x4a4/0x8a0 kernel/locking/lockdep.c:3702
 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:168 [inline]
 _raw_spin_unlock_irq+0x1f/0x80 kernel/locking/spinlock.c:199
 do_wait_for_common+0x232/0x370 kernel/sched/completion.c:85
 console_conditional_schedule+0x30/0x30
 __wait_for_common kernel/sched/completion.c:106 [inline]
 wait_for_common kernel/sched/completion.c:117 [inline]
 wait_for_completion+0x43/0x50 kernel/sched/completion.c:138
 kthread_stop+0xf8/0x200 kernel/kthread.c:572
 ubi_detach_mtd_dev+0x3b9/0x950 drivers/mtd/ubi/build.c:1101
 ctrl_cdev_ioctl+0x175/0x300 drivers/mtd/ubi/cdev.c:1068
 ubi_cdev_ioctl+0x1c00/0x1c00 drivers/mtd/ubi/cdev.c:869
 vfs_ioctl fs/ioctl.c:47 [inline]
 ksys_ioctl fs/ioctl.c:763 [inline]
 __do_sys_ioctl fs/ioctl.c:772 [inline]
 __se_sys_ioctl+0xf9/0x160 fs/ioctl.c:770
 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x49/0xb3
INFO: task syz-executor.1:11145 blocked for more than 143 seconds.
      Not tainted 5.7.0-rc2-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.1  D28608 11145   7064 0x00004004
Call Trace:
 context_switch kernel/sched/core.c:3372 [inline]
 __schedule+0x805/0xc90 kernel/sched/core.c:4088
 schedule+0x188/0x220 kernel/sched/core.c:4163
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4222
 __mutex_lock_common+0x129f/0x2fc0 kernel/locking/mutex.c:1033
 ctrl_cdev_ioctl+0x16c/0x300 drivers/mtd/ubi/cdev.c:1067
 __mutex_lock kernel/locking/mutex.c:1103 [inline]
 mutex_lock_nested+0x1a/0x20 kernel/locking/mutex.c:1118
 ctrl_cdev_ioctl+0x16c/0x300 drivers/mtd/ubi/cdev.c:1067
 ubi_cdev_ioctl+0x1c00/0x1c00 drivers/mtd/ubi/cdev.c:869
 vfs_ioctl fs/ioctl.c:47 [inline]
 ksys_ioctl fs/ioctl.c:763 [inline]
 __do_sys_ioctl fs/ioctl.c:772 [inline]
 __se_sys_ioctl+0xf9/0x160 fs/ioctl.c:770
 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x49/0xb3
INFO: task syz-executor.3:11146 blocked for more than 143 seconds.
      Not tainted 5.7.0-rc2-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.3  D28608 11146   7035 0x00004004
Call Trace:
 context_switch kernel/sched/core.c:3372 [inline]
 __schedule+0x805/0xc90 kernel/sched/core.c:4088
 schedule+0x188/0x220 kernel/sched/core.c:4163
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4222
 __mutex_lock_common+0x129f/0x2fc0 kernel/locking/mutex.c:1033
 ctrl_cdev_ioctl+0x16c/0x300 drivers/mtd/ubi/cdev.c:1067
 __mutex_lock kernel/locking/mutex.c:1103 [inline]
 mutex_lock_nested+0x1a/0x20 kernel/locking/mutex.c:1118
 ctrl_cdev_ioctl+0x16c/0x300 drivers/mtd/ubi/cdev.c:1067
 ubi_cdev_ioctl+0x1c00/0x1c00 drivers/mtd/ubi/cdev.c:869
 vfs_ioctl fs/ioctl.c:47 [inline]
 ksys_ioctl fs/ioctl.c:763 [inline]
 __do_sys_ioctl fs/ioctl.c:772 [inline]
 __se_sys_ioctl+0xf9/0x160 fs/ioctl.c:770
 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x49/0xb3
INFO: task syz-executor.4:11157 blocked for more than 143 seconds.
      Not tainted 5.7.0-rc2-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.4  D28560 11157   7054 0x00004004
Call Trace:
 context_switch kernel/sched/core.c:3372 [inline]
 __schedule+0x805/0xc90 kernel/sched/core.c:4088
 schedule+0x188/0x220 kernel/sched/core.c:4163
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4222
 __mutex_lock_common+0x129f/0x2fc0 kernel/locking/mutex.c:1033
 ctrl_cdev_ioctl+0x16c/0x300 drivers/mtd/ubi/cdev.c:1067
 __mutex_lock kernel/locking/mutex.c:1103 [inline]
 mutex_lock_nested+0x1a/0x20 kernel/locking/mutex.c:1118
 ctrl_cdev_ioctl+0x16c/0x300 drivers/mtd/ubi/cdev.c:1067
 ubi_cdev_ioctl+0x1c00/0x1c00 drivers/mtd/ubi/cdev.c:869
 vfs_ioctl fs/ioctl.c:47 [inline]
 ksys_ioctl fs/ioctl.c:763 [inline]
 __do_sys_ioctl fs/ioctl.c:772 [inline]
 __se_sys_ioctl+0xf9/0x160 fs/ioctl.c:770
 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x49/0xb3
INFO: task syz-executor.5:11165 blocked for more than 143 seconds.
      Not tainted 5.7.0-rc2-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.5  D28560 11165   7041 0x00004004
Call Trace:
 context_switch kernel/sched/core.c:3372 [inline]
 __schedule+0x805/0xc90 kernel/sched/core.c:4088
 schedule+0x188/0x220 kernel/sched/core.c:4163
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4222
 __mutex_lock_common+0x129f/0x2fc0 kernel/locking/mutex.c:1033
 ctrl_cdev_ioctl+0x16c/0x300 drivers/mtd/ubi/cdev.c:1067
 __mutex_lock kernel/locking/mutex.c:1103 [inline]
 mutex_lock_nested+0x1a/0x20 kernel/locking/mutex.c:1118
 ctrl_cdev_ioctl+0x16c/0x300 drivers/mtd/ubi/cdev.c:1067
 ubi_cdev_ioctl+0x1c00/0x1c00 drivers/mtd/ubi/cdev.c:869
 vfs_ioctl fs/ioctl.c:47 [inline]
 ksys_ioctl fs/ioctl.c:763 [inline]
 __do_sys_ioctl fs/ioctl.c:772 [inline]
 __se_sys_ioctl+0xf9/0x160 fs/ioctl.c:770
 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x49/0xb3
INFO: task syz-executor.5:11166 blocked for more than 143 seconds.
      Not tainted 5.7.0-rc2-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.5  D28560 11166   7041 0x00004004
Call Trace:
 context_switch kernel/sched/core.c:3372 [inline]
 __schedule+0x805/0xc90 kernel/sched/core.c:4088
 schedule+0x188/0x220 kernel/sched/core.c:4163
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4222
 __mutex_lock_common+0x129f/0x2fc0 kernel/locking/mutex.c:1033
 ctrl_cdev_ioctl+0x1b4/0x300 drivers/mtd/ubi/cdev.c:1042
 __mutex_lock kernel/locking/mutex.c:1103 [inline]
 mutex_lock_nested+0x1a/0x20 kernel/locking/mutex.c:1118
 ctrl_cdev_ioctl+0x1b4/0x300 drivers/mtd/ubi/cdev.c:1042
 ubi_cdev_ioctl+0x1c00/0x1c00 drivers/mtd/ubi/cdev.c:869
 vfs_ioctl fs/ioctl.c:47 [inline]
 ksys_ioctl fs/ioctl.c:763 [inline]
 __do_sys_ioctl fs/ioctl.c:772 [inline]
 __se_sys_ioctl+0xf9/0x160 fs/ioctl.c:770
 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x49/0xb3
INFO: task syz-executor.5:11180 blocked for more than 144 seconds.
      Not tainted 5.7.0-rc2-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.5  D28560 11180   7041 0x00004004
Call Trace:
 context_switch kernel/sched/core.c:3372 [inline]
 __schedule+0x805/0xc90 kernel/sched/core.c:4088
 schedule+0x188/0x220 kernel/sched/core.c:4163
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4222
 __mutex_lock_common+0x129f/0x2fc0 kernel/locking/mutex.c:1033
 ctrl_cdev_ioctl+0x16c/0x300 drivers/mtd/ubi/cdev.c:1067
 __mutex_lock kernel/locking/mutex.c:1103 [inline]
 mutex_lock_nested+0x1a/0x20 kernel/locking/mutex.c:1118
 ctrl_cdev_ioctl+0x16c/0x300 drivers/mtd/ubi/cdev.c:1067
 ubi_cdev_ioctl+0x1c00/0x1c00 drivers/mtd/ubi/cdev.c:869
 vfs_ioctl fs/ioctl.c:47 [inline]
 ksys_ioctl fs/ioctl.c:763 [inline]
 __do_sys_ioctl fs/ioctl.c:772 [inline]
 __se_sys_ioctl+0xf9/0x160 fs/ioctl.c:770
 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x49/0xb3
INFO: task syz-executor.0:11173 blocked for more than 144 seconds.
      Not tainted 5.7.0-rc2-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.0  D28608 11173   7040 0x00004004
Call Trace:
 context_switch kernel/sched/core.c:3372 [inline]
 __schedule+0x805/0xc90 kernel/sched/core.c:4088
 schedule+0x188/0x220 kernel/sched/core.c:4163
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4222
 __mutex_lock_common+0x129f/0x2fc0 kernel/locking/mutex.c:1033
 ctrl_cdev_ioctl+0x16c/0x300 drivers/mtd/ubi/cdev.c:1067
 __mutex_lock kernel/locking/mutex.c:1103 [inline]
 mutex_lock_nested+0x1a/0x20 kernel/locking/mutex.c:1118
 ctrl_cdev_ioctl+0x16c/0x300 drivers/mtd/ubi/cdev.c:1067
 ubi_cdev_ioctl+0x1c00/0x1c00 drivers/mtd/ubi/cdev.c:869
 vfs_ioctl fs/ioctl.c:47 [inline]
 ksys_ioctl fs/ioctl.c:763 [inline]
 __do_sys_ioctl fs/ioctl.c:772 [inline]
 __se_sys_ioctl+0xf9/0x160 fs/ioctl.c:770
 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x49/0xb3
INFO: task syz-executor.0:11177 blocked for more than 144 seconds.
      Not tainted 5.7.0-rc2-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.0  D28608 11177   7040 0x00004004
Call Trace:
 context_switch kernel/sched/core.c:3372 [inline]
 __schedule+0x805/0xc90 kernel/sched/core.c:4088
 schedule+0x188/0x220 kernel/sched/core.c:4163
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4222
 __mutex_lock_common+0x129f/0x2fc0 kernel/locking/mutex.c:1033
 ctrl_cdev_ioctl+0x1b4/0x300 drivers/mtd/ubi/cdev.c:1042
 __mutex_lock kernel/locking/mutex.c:1103 [inline]
 mutex_lock_nested+0x1a/0x20 kernel/locking/mutex.c:1118
 ctrl_cdev_ioctl+0x1b4/0x300 drivers/mtd/ubi/cdev.c:1042
 ubi_cdev_ioctl+0x1c00/0x1c00 drivers/mtd/ubi/cdev.c:869
 vfs_ioctl fs/ioctl.c:47 [inline]
 ksys_ioctl fs/ioctl.c:763 [inline]
 __do_sys_ioctl fs/ioctl.c:772 [inline]
 __se_sys_ioctl+0xf9/0x160 fs/ioctl.c:770
 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x49/0xb3
INFO: task syz-executor.0:11182 blocked for more than 144 seconds.
      Not tainted 5.7.0-rc2-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.0  D28608 11182   7040 0x00004004
Call Trace:
 context_switch kernel/sched/core.c:3372 [inline]
 __schedule+0x805/0xc90 kernel/sched/core.c:4088
 schedule+0x188/0x220 kernel/sched/core.c:4163
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4222
 __mutex_lock_common+0x129f/0x2fc0 kernel/locking/mutex.c:1033
 ctrl_cdev_ioctl+0x16c/0x300 drivers/mtd/ubi/cdev.c:1067
 __mutex_lock kernel/locking/mutex.c:1103 [inline]
 mutex_lock_nested+0x1a/0x20 kernel/locking/mutex.c:1118
 ctrl_cdev_ioctl+0x16c/0x300 drivers/mtd/ubi/cdev.c:1067
 ubi_cdev_ioctl+0x1c00/0x1c00 drivers/mtd/ubi/cdev.c:869
 vfs_ioctl fs/ioctl.c:47 [inline]
 ksys_ioctl fs/ioctl.c:763 [inline]
 __do_sys_ioctl fs/ioctl.c:772 [inline]
 __se_sys_ioctl+0xf9/0x160 fs/ioctl.c:770
 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x49/0xb3

Showing all locks held in the system:
1 lock held by khungtaskd/1139:
 #0: ffffffff892e85d0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 net/mptcp/pm_netlink.c:858
1 lock held by in:imklog/6689:
 #0: ffff88809eb26af0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x25d/0x2f0 fs/file.c:826
1 lock held by syz-executor.2/11136:
 #0: ffffffff894ce808 (ubi_devices_mutex){+.+.}-{3:3}, at: ctrl_cdev_ioctl+0x16c/0x300 drivers/mtd/ubi/cdev.c:1067
1 lock held by syz-executor.1/11145:
 #0: ffffffff894ce808 (ubi_devices_mutex){+.+.}-{3:3}, at: ctrl_cdev_ioctl+0x16c/0x300 drivers/mtd/ubi/cdev.c:1067
1 lock held by syz-executor.3/11146:
 #0: ffffffff894ce808 (ubi_devices_mutex){+.+.}-{3:3}, at: ctrl_cdev_ioctl+0x16c/0x300 drivers/mtd/ubi/cdev.c:1067
1 lock held by syz-executor.4/11157:
 #0: ffffffff894ce808 (ubi_devices_mutex){+.+.}-{3:3}, at: ctrl_cdev_ioctl+0x16c/0x300 drivers/mtd/ubi/cdev.c:1067
1 lock held by syz-executor.5/11165:
 #0: ffffffff894ce808 (ubi_devices_mutex){+.+.}-{3:3}, at: ctrl_cdev_ioctl+0x16c/0x300 drivers/mtd/ubi/cdev.c:1067
1 lock held by syz-executor.5/11166:
 #0: ffffffff894ce808 (ubi_devices_mutex){+.+.}-{3:3}, at: ctrl_cdev_ioctl+0x1b4/0x300 drivers/mtd/ubi/cdev.c:1042
1 lock held by syz-executor.5/11180:
 #0: ffffffff894ce808 (ubi_devices_mutex){+.+.}-{3:3}, at: ctrl_cdev_ioctl+0x16c/0x300 drivers/mtd/ubi/cdev.c:1067
1 lock held by syz-executor.0/11173:
 #0: ffffffff894ce808 (ubi_devices_mutex){+.+.}-{3:3}, at: ctrl_cdev_ioctl+0x16c/0x300 drivers/mtd/ubi/cdev.c:1067
1 lock held by syz-executor.0/11177:
 #0: ffffffff894ce808 (ubi_devices_mutex){+.+.}-{3:3}, at: ctrl_cdev_ioctl+0x1b4/0x300 drivers/mtd/ubi/cdev.c:1042
1 lock held by syz-executor.0/11182:
 #0: ffffffff894ce808 (ubi_devices_mutex){+.+.}-{3:3}, at: ctrl_cdev_ioctl+0x16c/0x300 drivers/mtd/ubi/cdev.c:1067

=============================================

NMI backtrace for cpu 1
CPU: 1 PID: 1139 Comm: khungtaskd Not tainted 5.7.0-rc2-syzkaller #0
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+0x1e9/0x30e lib/dump_stack.c:118
 nmi_cpu_backtrace+0x9f/0x180 lib/nmi_backtrace.c:101
 arch_trigger_cpumask_backtrace+0x10/0x10 arch/x86/kernel/apic/hw_nmi.c:38
 nmi_trigger_cpumask_backtrace+0x16a/0x280 lib/nmi_backtrace.c:62
 check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline]
 watchdog+0xd2a/0xd40 kernel/hung_task.c:289
 kthread+0x353/0x380 kernel/kthread.c:268
 hungtask_pm_notify+0x50/0x50 kernel/hung_task.c:265
 kthread_blkcg+0xd0/0xd0 kernel/kthread.c:1247
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 4104 Comm: systemd-journal Not tainted 5.7.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:check_memory_region_inline mm/kasan/generic.c:176 [inline]
RIP: 0010:check_memory_region+0x14/0x2f0 mm/kasan/generic.c:193
Code: c0 e8 9d 61 ab ff eb d3 cc cc cc cc cc cc cc cc cc cc cc cc cc cc 41 57 41 56 41 55 41 54 53 b0 01 48 85 f6 0f 84 0d 02 00 00 <48> 89 fb 48 f7 d3 48 39 f3 0f 82 8a 02 00 00 48 89 fb 48 c1 eb 2f
RSP: 0018:ffffc90001277ba8 EFLAGS: 00000202
RAX: 1ffffffff1215d01 RBX: ffff8880ae838398 RCX: ffffffff8160a8f3
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff8880ae838398
RBP: ffff88821bc55f00 R08: ffffffff839ca9c3 R09: ffffed1015d07074
R10: ffffed1015d07074 R11: 0000000000000000 R12: 1ffff9200024efab
R13: 0000000000000000 R14: ffffffff890ae8d0 R15: dffffc0000000000
FS:  00007fabc89f58c0(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fabc5f45000 CR3: 0000000093260000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 atomic_read include/asm-generic/atomic-instrumented.h:26 [inline]
 rcu_dynticks_curr_cpu_in_eqs kernel/rcu/tree.c:302 [inline]
 rcu_is_watching+0x53/0xa0 kernel/rcu/tree.c:929
 rcu_read_unlock include/linux/rcupdate.h:651 [inline]
 mntput_no_expire+0x162/0xca0 fs/namespace.c:1139
 path_put fs/namei.c:483 [inline]
 terminate_walk+0x1ec/0x560 fs/namei.c:579
 path_parentat fs/namei.c:2379 [inline]
 filename_parentat+0x1d1/0xf50 fs/namei.c:2393
 pfn_valid include/linux/mmzone.h:1331 [inline]
 __virt_addr_valid+0x1fd/0x290 arch/x86/mm/physaddr.c:65
 __phys_addr_symbol+0x2b/0x70 arch/x86/mm/physaddr.c:42
 __check_object_size+0x2fd/0x3f0 mm/usercopy.c:290
 filename_create+0x5e/0x630 fs/namei.c:3427
 audit_dummy_context include/linux/audit.h:296 [inline]
 audit_getname include/linux/audit.h:327 [inline]
 getname_flags+0x20d/0x610 fs/namei.c:202
 user_path_create fs/namei.c:3502 [inline]
 do_mkdirat+0x56/0x310 fs/namei.c:3640
 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x49/0xb3
RIP: 0033:0x7fabc7cb1687
Code: 00 b8 ff ff ff ff c3 0f 1f 40 00 48 8b 05 09 d8 2b 00 64 c7 00 5f 00 00 00 b8 ff ff ff ff c3 0f 1f 40 00 b8 53 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d e1 d7 2b 00 f7 d8 64 89 01 48
RSP: 002b:00007ffe8b483ea8 EFLAGS: 00000293 ORIG_RAX: 0000000000000053
RAX: ffffffffffffffda RBX: 00007ffe8b486dc0 RCX: 00007fabc7cb1687
RDX: 00007fabc8722a00 RSI: 00000000000001ed RDI: 00005639c64998a0
RBP: 00007ffe8b483ee0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000069 R11: 0000000000000293 R12: 0000000000000000
R13: 0000000000000000 R14: 00007ffe8b486dc0 R15: 00007ffe8b4843d0
Crashes (4):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	Maintainers
ci-upstream-kasan-gce-smack-root	2020/04/21 23:59	upstream	189522da	2e44d63e	.config	log	report	syz	linux-kernel@vger.kernel.org, linux-mtd@lists.infradead.org, miquel.raynal@bootlin.com, richard@nod.at, vigneshr@ti.com
ci-upstream-kasan-gce-root	2020/02/22 17:20	upstream	54dedb5b	2c36e7a7	.config	log	report	syz	linux-kernel@vger.kernel.org, linux-mtd@lists.infradead.org, miquel.raynal@bootlin.com, richard@nod.at, vigneshr@ti.com
ci-upstream-linux-next-kasan-gce-root	2020/05/20 09:18	linux-next	ac935d22	67fa1f59	.config	log	report	syz	linux-kernel@vger.kernel.org, linux-mtd@lists.infradead.org, miquel.raynal@bootlin.com, richard@nod.at, vigneshr@ti.com
ci-upstream-linux-next-kasan-gce-root	2020/02/20 02:57	linux-next	1d7f85df	b690a6e3	.config	log	report		linux-kernel@vger.kernel.org, linux-mtd@lists.infradead.org, miquel.raynal@bootlin.com, richard@nod.at, vigneshr@ti.com