syzbot


INFO: task hung in grab_super

Status: upstream: reported on 2024/04/01 06:22
Reported-by: syzbot+e95ecb8d314d1cf4bb71@syzkaller.appspotmail.com
First crash: 80d, last: 80d
Similar bugs (9)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-414 INFO: task hung in grab_super 4 2059d 1897d 0/1 auto-closed as invalid on 2019/04/28 15:34
linux-4.14 INFO: task hung in grab_super C error 241 573d 1888d 0/1 upstream: reported C repro on 2019/04/19 12:37
android-414 INFO: task hung in grab_super (2) 2 1798d 1820d 0/1 auto-closed as invalid on 2019/11/15 12:55
android-49 INFO: task hung in grab_super 1 2137d 2137d 0/3 auto-closed as invalid on 2019/02/22 13:19
upstream INFO: task hung in grab_super udf C 209 515d 2164d 0/27 closed as dup on 2018/07/18 11:42
linux-6.1 INFO: task hung in grab_super 1 75d 75d 0/3 upstream: reported on 2024/04/06 01:06
linux-4.19 INFO: task hung in grab_super vfs udf C error 249 496d 1890d 0/1 upstream: reported C repro on 2019/04/18 03:33
upstream INFO: task hung in grab_super (2) fs 1 379d 379d 0/27 auto-obsoleted due to no activity on 2023/09/05 02:19
android-49 INFO: task hung in grab_super (2) 1 1765d 1765d 0/3 auto-closed as invalid on 2019/12/19 00:51

Sample crash report:
INFO: task syz-executor.3:16539 blocked for more than 143 seconds.
      Not tainted 5.15.153-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.3  state:D stack:26912 pid:16539 ppid:  3525 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5030 [inline]
 __schedule+0x12c4/0x45b0 kernel/sched/core.c:6376
 schedule+0x11b/0x1f0 kernel/sched/core.c:6459
 rwsem_down_write_slowpath+0xebb/0x15c0 kernel/locking/rwsem.c:1157
 __down_write_common kernel/locking/rwsem.c:1284 [inline]
 __down_write kernel/locking/rwsem.c:1293 [inline]
 down_write+0x164/0x170 kernel/locking/rwsem.c:1542
 grab_super+0x59/0x1a0 fs/super.c:389
 sget+0x1ae/0x4d0 fs/super.c:616
 mount_bdev+0xf0/0x3f0 fs/super.c:1360
 legacy_get_tree+0xeb/0x180 fs/fs_context.c:611
 vfs_get_tree+0x88/0x270 fs/super.c:1517
 do_new_mount+0x2ba/0xb40 fs/namespace.c:3005
 do_mount fs/namespace.c:3348 [inline]
 __do_sys_mount fs/namespace.c:3556 [inline]
 __se_sys_mount+0x2d5/0x3c0 fs/namespace.c:3533
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f005a90fda9
RSP: 002b:00007f0058e900c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f005aa3df80 RCX: 00007f005a90fda9
RDX: 0000000020000100 RSI: 00000000200000c0 RDI: 0000000020000340
RBP: 00007f005a95c47a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000008000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f005aa3df80 R15: 00007fffe28cf048
 </TASK>

Showing all locks held in the system:
5 locks held by kworker/u4:0/9:
 #0: ffff888011dcd138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283
 #1: ffffc90000ce7d20 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285
 #2: ffffffff8d9d0550 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0xf1/0xb60 net/core/net_namespace.c:558
 #3: ffffffff8d9dc108 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock_unregistering net/core/dev.c:11579 [inline]
 #3: ffffffff8d9dc108 (rtnl_mutex){+.+.}-{3:3}, at: default_device_exit_batch+0x1ac/0x3f0 net/core/dev.c:11617
 #4: ffffffff8c923ce8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline]
 #4: ffffffff8c923ce8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x280/0x740 kernel/rcu/tree_exp.h:845
1 lock held by khungtaskd/27:
 #0: ffffffff8c91f720 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
1 lock held by dhcpcd/3176:
 #0: ffffffff8d9dc108 (rtnl_mutex){+.+.}-{3:3}, at: devinet_ioctl+0x2a5/0x1b20 net/ipv4/devinet.c:1066
2 locks held by getty/3272:
 #0: ffff8880248a5098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc90002bab2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6af/0x1db0 drivers/tty/n_tty.c:2158
2 locks held by kworker/u4:7/3722:
2 locks held by kworker/1:16/4696:
 #0: ffff888011c72138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283
 #1: ffffc900056efd20 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285
3 locks held by kworker/1:19/4839:
 #0: ffff888011c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283
 #1: ffffc90002ba7d20 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285
 #2: ffff88801b10d400 (&nsim_dev->port_list_lock#2){+.+.}-{3:3}, at: nsim_dev_trap_report_work+0x56/0xab0 drivers/net/netdevsim/dev.c:757
3 locks held by kworker/1:27/6971:
 #0: ffff888011c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283
 #1: ffffc90004397d20 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285
 #2: ffffffff8c923ce8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline]
 #2: ffffffff8c923ce8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x350/0x740 kernel/rcu/tree_exp.h:845
1 lock held by syz-executor.0/13716:
2 locks held by syz-executor.4/16435:
 #0: ffff88807a75a0e0 (&type->s_umount_key#104/1){+.+.}-{3:3}, at: alloc_super+0x210/0x940 fs/super.c:229
 #1: ffff8880261f6068 (&sbi->hpfs_mutex){+.+.}-{3:3}, at: hpfs_lock fs/hpfs/hpfs_fn.h:366 [inline]
 #1: ffff8880261f6068 (&sbi->hpfs_mutex){+.+.}-{3:3}, at: hpfs_fill_super+0x221/0x2580 fs/hpfs/super.c:564
2 locks held by syz-executor.3/16539:
 #0: ffff88814083c108 (&bdev->bd_fsfreeze_mutex){+.+.}-{3:3}, at: mount_bdev+0x8b/0x3f0 fs/super.c:1354
 #1: ffff88807a75a0e0 (&type->s_umount_key#105){+.+.}-{3:3}, at: grab_super+0x59/0x1a0 fs/super.c:389
7 locks held by syz-executor.2/19236:
 #0: ffff88807f0c8460 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x29a/0xe50 fs/read_write.c:590
 #1: ffff88805edd0c88 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e7/0x4f0 fs/kernfs/file.c:287
 #2: ffff888147b7dbd0 (kn->active#233){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x20b/0x4f0 fs/kernfs/file.c:288
 #3: ffffffff8d357be8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xf1/0x470 drivers/net/netdevsim/bus.c:344
 #4: ffff88801b10c178 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:760 [inline]
 #4: ffff88801b10c178 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1044 [inline]
 #4: ffff88801b10c178 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xc2/0x7f0 drivers/base/dd.c:1259
 #5: ffff88801b10d400 (&nsim_dev->port_list_lock#2){+.+.}-{3:3}, at: nsim_dev_port_del_all drivers/net/netdevsim/dev.c:1359 [inline]
 #5: ffff88801b10d400 (&nsim_dev->port_list_lock#2){+.+.}-{3:3}, at: nsim_dev_reload_destroy+0x118/0x240 drivers/net/netdevsim/dev.c:1561
 #6: ffffffff8d9dc108 (rtnl_mutex){+.+.}-{3:3}, at: netdev_run_todo+0xa4f/0xc40 net/core/dev.c:10655
1 lock held by syz-executor.3/19352:
 #0: ffffffff8d9dc108 (rtnl_mutex){+.+.}-{3:3}, at: ipv6_route_ioctl+0x4c1/0x7b0 net/ipv6/route.c:4486
1 lock held by syz-executor.3/19355:
 #0: ffffffff8d9dc108 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_add_ifaddr+0x1f8/0x340 net/ipv6/addrconf.c:3092
1 lock held by syz-executor.4/19354:
 #0: ffff88802bc960e0 (&type->s_umount_key#28/1){+.+.}-{3:3}, at: alloc_super+0x210/0x940 fs/super.c:229
2 locks held by syz-executor.0/19362:
 #0: ffffffff8da39830 (cb_lock){++++}-{3:3}, at: genl_rcv+0x15/0x40 net/netlink/genetlink.c:802
 #1: ffffffff8d9dc108 (rtnl_mutex){+.+.}-{3:3}, at: nl80211_pre_doit+0x28/0x540 net/wireless/nl80211.c:14963
2 locks held by syz-executor.1/19364:
 #0: ffff88801b8ed918 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0xfb/0x790 block/bdev.c:912
 #1: ffff88801b980468 (&lo->lo_mutex){+.+.}-{3:3}, at: lo_release+0x4d/0x1f0 drivers/block/loop.c:2070

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

NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.15.153-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline]
 watchdog+0xe72/0xeb0 kernel/hung_task.c:295
 kthread+0x3f6/0x4f0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 3722 Comm: kworker/u4:7 Not tainted 5.15.153-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Workqueue: bat_events batadv_nc_worker
RIP: 0010:check_kcov_mode kernel/kcov.c:174 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x32/0x60 kernel/kcov.c:197
Code: 04 36 82 7e 65 8b 15 05 36 82 7e f7 c2 00 01 ff 00 74 11 f7 c2 00 01 00 00 74 35 83 b9 34 16 00 00 00 74 2c 8b 91 10 16 00 00 <83> fa 02 75 21 48 8b 91 18 16 00 00 48 8b 32 48 8d 7e 01 8b 89 14
RSP: 0018:ffffc90003317b58 EFLAGS: 00000246
RAX: ffffffff89f9c6ee RBX: ffffffff89f9c760 RCX: ffff888018db8000
RDX: 0000000000000000 RSI: ffffffff8a8b1500 RDI: ffffffff8ad88fc0
RBP: 000000000000000e R08: dffffc0000000000 R09: fffffbfff1f7a035
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000400
R13: dffffc0000000000 R14: ffff88802b22eb00 R15: ffff88802b22eb10
FS:  0000000000000000(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4da81cd620 CR3: 00000000238de000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 batadv_nc_purge_paths+0x33e/0x3b0 net/batman-adv/network-coding.c:441
 batadv_nc_worker+0x2cf/0x5b0 net/batman-adv/network-coding.c:724
 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310
 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457
 kthread+0x3f6/0x4f0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/04/01 06:21 linux-5.15.y 9465fef4ae35 6baf5069 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in grab_super
* Struck through repros no longer work on HEAD.