[syzbot] [kernfs?] INFO: task hung in do_coredump (3)

[syzbot <syzbot+a8cdfe2d8ad35db3a7fd@syzkaller.appspotmail.com>]

Hello,

syzbot found the following issue on:

HEAD commit:    c964ced77262 Merge tag 'for-linus' of git://git.kernel.org..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=13dbcf27980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=64667415a04ab9c4
dashboard link: https://syzkaller.appspot.com/bug?extid=a8cdfe2d8ad35db3a7fd
compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/8e033b304e7a/disk-c964ced7.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/4f886da219e0/vmlinux-c964ced7.xz
kernel image: https://storage.googleapis.com/syzbot-assets/814a8b44477f/bzImage-c964ced7.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+a8cdfe2d8ad35db3a7fd@syzkaller.appspotmail.com

INFO: task syz.0.801:10223 blocked for more than 143 seconds.
      Not tainted 6.12.0-rc3-syzkaller-00087-gc964ced77262 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.801       state:D stack:28592 pid:10223 tgid:10220 ppid:9895   flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5322 [inline]
 __schedule+0xef5/0x5750 kernel/sched/core.c:6682
 __schedule_loop kernel/sched/core.c:6759 [inline]
 schedule+0xe7/0x350 kernel/sched/core.c:6774
 schedule_timeout+0x258/0x2a0 kernel/time/timer.c:2591
 do_wait_for_common kernel/sched/completion.c:95 [inline]
 __wait_for_common+0x3e1/0x600 kernel/sched/completion.c:116
 wait_for_common kernel/sched/completion.c:127 [inline]
 wait_for_completion_state+0x1c/0x40 kernel/sched/completion.c:264
 coredump_wait fs/coredump.c:418 [inline]
 do_coredump+0x82f/0x4160 fs/coredump.c:575
 get_signal+0x237c/0x26d0 kernel/signal.c:2902
 arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x150/0x2a0 kernel/entry/common.c:218
 do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f282b37dff9
RSP: 002b:00007f282c1850e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007f282b536060 RCX: 00007f282b37dff9
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f282b536064
RBP: 00007f282b536058 R08: 00007f282c1a7080 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f282b536064
R13: 0000000000000000 R14: 00007ffcdfcd02c0 R15: 00007ffcdfcd03a8
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/u8:1/12:
 #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1212/0x1b30 kernel/workqueue.c:3204
 #1: ffffc90000117d80 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x8bb/0x1b30 kernel/workqueue.c:3205
 #2: ffffffff8fac4128 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0x51/0xc0 net/core/link_watch.c:276
1 lock held by khungtaskd/30:
 #0: ffffffff8ddb7800 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
 #0: ffffffff8ddb7800 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8ddb7800 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x7f/0x390 kernel/locking/lockdep.c:6720
5 locks held by kworker/u8:5/1104:
 #0: ffff88801baed948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x1212/0x1b30 kernel/workqueue.c:3204
 #1: ffffc90003e27d80 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x8bb/0x1b30 kernel/workqueue.c:3205
 #2: ffffffff8faae510 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0xbb/0xb40 net/core/net_namespace.c:580
 #3: ffffffff8fac4128 (rtnl_mutex){+.+.}-{3:3}, at: default_device_exit_batch+0x8f/0x9b0 net/core/dev.c:11934
 #4: ffffffff8ddc30f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock+0x282/0x3b0 kernel/rcu/tree_exp.h:297
3 locks held by kworker/u8:7/2921:
 #0: ffff88814c578948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x1212/0x1b30 kernel/workqueue.c:3204
 #1: ffffc90009917d80 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x8bb/0x1b30 kernel/workqueue.c:3205
 #2: ffffffff8fac4128 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xcf/0x14d0 net/ipv6/addrconf.c:4196
2 locks held by dhcpcd/4901:
 #0: ffff88803129c6c8 (nlk_cb_mutex-ROUTE){+.+.}-{3:3}, at: __netlink_dump_start+0x154/0x980 net/netlink/af_netlink.c:2405
 #1: ffffffff8fac4128 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
 #1: ffffffff8fac4128 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_dumpit+0x18f/0x1f0 net/core/rtnetlink.c:6534
2 locks held by getty/4989:
 #0: ffff888031d4a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
 #1: ffffc900031332f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xfba/0x1480 drivers/tty/n_tty.c:2211
1 lock held by syz.1.644/8939:
1 lock held by syz.0.801/10221:
1 lock held by syz-executor/11581:
 #0: ffffffff8fac4128 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
 #0: ffffffff8fac4128 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x372/0xea0 net/core/rtnetlink.c:6672
1 lock held by syz-executor/11673:
 #0: ffffffff8fac4128 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
 #0: ffffffff8fac4128 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x372/0xea0 net/core/rtnetlink.c:6672
1 lock held by syz-executor/11679:
 #0: ffffffff8fac4128 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
 #0: ffffffff8fac4128 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x372/0xea0 net/core/rtnetlink.c:6672
1 lock held by syz-executor/11682:
 #0: ffffffff8fac4128 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
 #0: ffffffff8fac4128 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x372/0xea0 net/core/rtnetlink.c:6672

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.12.0-rc3-syzkaller-00087-gc964ced77262 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline]
 watchdog+0xf0c/0x1240 kernel/hung_task.c:379
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 8939 Comm: syz.1.644 Not tainted 6.12.0-rc3-syzkaller-00087-gc964ced77262 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:sha256_transform_rorx+0x491/0x1120 arch/x86/crypto/sha256-avx2-asm.S:600
Code: 00 c2 45 31 e6 c4 63 7b f0 e1 02 c4 c1 7d fe c0 45 31 e6 41 89 cc 41 21 d4 45 01 ef c5 fd 70 d0 50 44 09 e6 44 01 f3 45 01 f9 <44> 01 fb 01 f3 89 de c4 43 7b f0 e9 19 c4 43 7b f0 f1 0b 03 44 3c
RSP: 0018:ffffc900115f7200 EFLAGS: 00000207
RAX: 000000003357dd5f RBX: 0000000090041468 RCX: 00000000a7e785dd
RDX: 000000009f51b31d RSI: 000000008f51b59d RDI: 0000000000000080
RBP: ffffc900115f7420 R08: 00000000cd5035ab R09: 0000000068c009dd
R10: 00000000ca0dc7c0 R11: 00000000ff34e361 R12: 000000008741811d
R13: 00000000fdd296c2 R14: 00000000d903a8d4 R15: 00000000f9297221
FS:  00007f704af0b6c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000556573553680 CR3: 0000000050cbe000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 lib_sha256_base_do_update include/crypto/sha256_base.h:63 [inline]
 sha256_base_do_update include/crypto/sha256_base.h:81 [inline]
 _sha256_update arch/x86/crypto/sha256_ssse3_glue.c:74 [inline]
 _sha256_update+0x17e/0x220 arch/x86/crypto/sha256_ssse3_glue.c:58
 ima_calc_file_hash_tfm+0x302/0x3e0 security/integrity/ima/ima_crypto.c:491
 ima_calc_file_shash security/integrity/ima/ima_crypto.c:511 [inline]
 ima_calc_file_hash+0x1ba/0x490 security/integrity/ima/ima_crypto.c:568
 ima_collect_measurement+0x8a7/0xa10 security/integrity/ima/ima_api.c:293
 process_measurement+0x1271/0x2370 security/integrity/ima/ima_main.c:372
 ima_file_mmap+0x1b1/0x1d0 security/integrity/ima/ima_main.c:462
 security_mmap_file+0x8bd/0x990 security/security.c:2979
 vm_mmap_pgoff+0xdb/0x360 mm/util.c:584
 ksys_mmap_pgoff+0x1c8/0x5c0 mm/mmap.c:542
 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:86 [inline]
 __se_sys_mmap arch/x86/kernel/sys_x86_64.c:79 [inline]
 __x64_sys_mmap+0x125/0x190 arch/x86/kernel/sys_x86_64.c:79
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f704a17dff9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f704af0b038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007f704a335f80 RCX: 00007f704a17dff9
RDX: 00004000000000df RSI: 0000002000000004 RDI: 0000000000000002
RBP: 00007f704a1f0296 R08: 0000000000000404 R09: 0000300000000000
R10: 0000000000040eb2 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f704a335f80 R15: 00007ffeb08cd318
 </TASK>


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