[syzbot] [kernel?] INFO: task hung in vfs_coredump (2)

[syzbot] [kernel?] INFO: task hung in vfs_coredump (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    d086c886ceb9 Add linux-next specific files for 20250718
git tree:       linux-next
console+strace: https://syzkaller.appspot.com/x/log.txt?x=127b0ca2580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=69896dd7b8c4e81e
dashboard link: https://syzkaller.appspot.com/bug?extid=6ed94e81a1492fe1d512
compiler:       Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=12dbcca2580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=13238834580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/54504fbc2437/disk-d086c886.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/b427b00abffe/vmlinux-d086c886.xz
kernel image: https://storage.googleapis.com/syzbot-assets/5a87731b006b/bzImage-d086c886.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+6ed94e81a1492fe1d512@syzkaller.appspotmail.com

INFO: task syz-executor104:5856 blocked for more than 143 seconds.
      Not tainted 6.16.0-rc6-next-20250718-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor104 state:D stack:26808 pid:5856  tgid:5854  ppid:5853   task_flags:0x400640 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5351 [inline]
 __schedule+0x1737/0x4d30 kernel/sched/core.c:6954
 __schedule_loop kernel/sched/core.c:7036 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:7051
 schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75
 do_wait_for_common kernel/sched/completion.c:100 [inline]
 __wait_for_common+0x3da/0x710 kernel/sched/completion.c:121
 wait_for_common kernel/sched/completion.c:132 [inline]
 wait_for_completion_state+0x1c/0x40 kernel/sched/completion.c:269
 coredump_wait fs/coredump.c:534 [inline]
 vfs_coredump+0x8c2/0x2ab0 fs/coredump.c:1128
 get_signal+0x1109/0x1340 kernel/signal.c:3019
 arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:40
 exit_to_user_mode_prepare include/linux/irq-entry-common.h:208 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
 do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7bc88c77a9
RSP: 002b:00007f7bc885f198 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: 00000000000000ca RBX: 00007f7bc89513f8 RCX: 00007f7bc88c77a9
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f7bc89513fc
RBP: 00007f7bc89513f0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f7bc891e0c4
R13: 000000000000006e R14: 00002000000003c0 R15: 00002000000001c0
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/31:
 #0: ffffffff8e53d8a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8e53d8a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #0: ffffffff8e53d8a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770
2 locks held by getty/5611:
 #0: ffff88814d1c60a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc900036cc2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc6-next-20250718-syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline]
 watchdog+0xf93/0xfe0 kernel/hung_task.c:491
 kthread+0x70e/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted 6.16.0-rc6-next-20250718-syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82
Code: d3 e8 02 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 13 ba 28 00 f3 0f 1e fa fb f4 <c3> cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90000197de0 EFLAGS: 000002c2
RAX: eba1d665c07d2f00 RBX: ffffffff8196da38 RCX: eba1d665c07d2f00
RDX: 0000000000000001 RSI: ffffffff8dc6a0fe RDI: ffffffff8c04d400
RBP: ffffc90000197f20 R08: ffff8880b8732f5b R09: 1ffff110170e65eb
R10: dffffc0000000000 R11: ffffed10170e65ec R12: ffffffff8fe3cf30
R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff11003a55b40
FS:  0000000000000000(0000) GS:ffff8881258ab000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000563b2a68e168 CR3: 000000000e338000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
 default_idle+0x13/0x20 arch/x86/kernel/process.c:757
 default_idle_call+0x74/0xb0 kernel/sched/idle.c:122
 cpuidle_idle_call kernel/sched/idle.c:190 [inline]
 do_idle+0x1e8/0x510 kernel/sched/idle.c:330
 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428
 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:315
 common_startup_64+0x13e/0x147
 </TASK>


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.

If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup

Re: [syzbot] [kernel?] INFO: task hung in vfs_coredump (2)

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
INFO: task hung in vfs_coredump

INFO: task syz.0.17:6440 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.17        state:D stack:28400 pid:6440  tgid:6438  ppid:6342   task_flags:0x400640 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5298 [inline]
 __schedule+0xfee/0x6120 kernel/sched/core.c:6911
 __schedule_loop kernel/sched/core.c:6993 [inline]
 schedule+0xdd/0x390 kernel/sched/core.c:7008
 schedule_timeout+0x1b2/0x280 kernel/time/sleep_timeout.c:75
 do_wait_for_common kernel/sched/completion.c:100 [inline]
 __wait_for_common+0x2e7/0x4c0 kernel/sched/completion.c:121
 wait_for_common kernel/sched/completion.c:132 [inline]
 wait_for_completion_state+0x1c/0x40 kernel/sched/completion.c:269
 coredump_wait fs/coredump.c:534 [inline]
 vfs_coredump+0x80d/0x5570 fs/coredump.c:1197
 get_signal+0x1f2a/0x21e0 kernel/signal.c:3019
 arch_do_signal_or_restart+0x91/0x770 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
 exit_to_user_mode_loop+0x86/0x4a0 kernel/entry/common.c:98
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline]
 do_syscall_64+0x668/0xf80 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0a20d9af39
RSP: 002b:00007f0a21b690e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007f0a21006098 RCX: 00007f0a20d9af39
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f0a2100609c
RBP: 00007f0a21006090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0a21006128 R14: 00007ffdc3a2cb70 R15: 00007ffdc3a2cc58
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/30:
 #0: ffffffff8e5ce2e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
 #0: ffffffff8e5ce2e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
 #0: ffffffff8e5ce2e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775
4 locks held by kworker/u8:4/60:
 #0: ffff8880b853b2e0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2c/0x140 kernel/sched/core.c:647
 #1: ffff8880b8524648 (psi_seq){-.-.}-{0:0}, at: psi_sched_switch kernel/sched/stats.h:225 [inline]
 #1: ffff8880b8524648 (psi_seq){-.-.}-{0:0}, at: __schedule+0x2c11/0x6120 kernel/sched/core.c:6905
 #2: ffff8880b8526358 (&base->lock){-.-.}-{2:2}, at: __mod_timer+0x6e7/0xca0 kernel/time/timer.c:1117
 #3: ffffffff9b0f2e60 (&obj_hash[i].lock){-.-.}-{2:2}, at: debug_object_activate+0x144/0x490 lib/debugobjects.c:835
2 locks held by getty/5582:
 #0: ffff888032e940a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x1500 drivers/tty/n_tty.c:2211
1 lock held by syz.0.17/6439:
1 lock held by syz.1.18/6463:
1 lock held by syz.2.19/6486:
2 locks held by syz.3.20/6516:
1 lock held by syz.4.21/6547:
1 lock held by syz.5.22/6577:
1 lock held by syz.6.23/6614:
1 lock held by syz.7.24/6647:

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x1d7/0x230 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline]
 __sys_info lib/sys_info.c:157 [inline]
 sys_info+0x141/0x190 lib/sys_info.c:165
 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
 watchdog+0xd25/0x1050 kernel/hung_task.c:515
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 6486 Comm: syz.2.19 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:sha256_transform_rorx+0xdd2/0x1110 lib/crypto/x86/sha256-avx2-asm.S:650
Code: c4 43 7b f0 e3 02 44 03 54 3c 14 09 de 45 31 e6 45 89 dc 21 c6 41 21 dc 45 01 ef 44 01 d1 44 09 e6 45 01 f2 44 01 f9 45 01 fa <45> 89 c7 c4 63 7b f0 e9 19 c4 63 7b f0 f1 0b 41 31 d7 45 31 f5 c4
RSP: 0018:ffffc900033970a0 EFLAGS: 00000a03
RAX: 000000000fc16320 RBX: 0000000041b41c96 RCX: 00000000e2f40420
RDX: 00000000415f425e RSI: 00000000099521a6 RDI: 0000000000000100
RBP: ffffc900033972c0 R08: 00000000ec3afa8e R09: 00000000be60ae5f
R10: 000000006a33a7ef R11: 00000000991721ee R12: 0000000001140086
R13: 0000000077102bc3 R14: 00000000f5b6baa6 R15: 00000000c96a7222
FS:  00007f1f36bc06c0(0000) GS:ffff88812472f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f331ad05ff8 CR3: 000000002b7a6000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 sha256_blocks_avx2+0x49/0x90 lib/crypto/x86/sha256.h:31
 sha256_blocks lib/crypto/x86/sha256.h:37 [inline]
 __sha256_update+0x188/0x1c0 lib/crypto/sha256.c:208
 crypto_sha256_update+0x23/0x30 crypto/sha256.c:142
 crypto_shash_finup+0x34b/0x6b0 crypto/shash.c:123
 crypto_shash_update include/crypto/hash.h:1006 [inline]
 ima_calc_file_hash_tfm+0x299/0x350 security/integrity/ima/ima_crypto.c:491
 ima_calc_file_shash security/integrity/ima/ima_crypto.c:511 [inline]
 ima_calc_file_hash+0x18c/0x480 security/integrity/ima/ima_crypto.c:568
 ima_collect_measurement+0x887/0xa40 security/integrity/ima/ima_api.c:295
 process_measurement+0xdfe/0x2350 security/integrity/ima/ima_main.c:407
 ima_file_mmap+0x1c4/0x1f0 security/integrity/ima/ima_main.c:505
 security_mmap_file+0x278/0x9b0 security/security.c:2504
 vm_mmap_pgoff+0xec/0x470 mm/util.c:575
 ksys_mmap_pgoff+0x273/0x650 mm/mmap.c:605
 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:89 [inline]
 __se_sys_mmap arch/x86/kernel/sys_x86_64.c:82 [inline]
 __x64_sys_mmap+0x125/0x190 arch/x86/kernel/sys_x86_64.c:82
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1f35d9af39
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f1f36bc0028 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007f1f36005fa0 RCX: 00007f1f35d9af39
RDX: 00004000000000df RSI: 0000004000000001 RDI: 0000000000000008
RBP: 00007f1f35e2fee0 R08: ffffffffffffffff R09: 0000300000000000
R10: 0000000000040eb1 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1f36006038 R14: 00007f1f36005fa0 R15: 00007fff0f5b0ad8
 </TASK>


Tested on:

commit:         113ae7b4 Merge tag 'hwmon-for-v7.0-rc5' of git://git.k..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1242ccba580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=c91defb609dfc805
dashboard link: https://syzkaller.appspot.com/bug?extid=6ed94e81a1492fe1d512
compiler:       gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44
patch:          https://syzkaller.appspot.com/x/patch.diff?x=10bcccba580000

Re: [syzbot] [kernel?] INFO: task hung in vfs_coredump (2)

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
INFO: task hung in vfs_coredump

INFO: task syz.0.17:6434 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.17        state:D stack:28424 pid:6434  tgid:6432  ppid:6327   task_flags:0x400640 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5298 [inline]
 __schedule+0xfee/0x6120 kernel/sched/core.c:6911
 __schedule_loop kernel/sched/core.c:6993 [inline]
 schedule+0xdd/0x390 kernel/sched/core.c:7008
 schedule_timeout+0x1b2/0x280 kernel/time/sleep_timeout.c:75
 do_wait_for_common kernel/sched/completion.c:100 [inline]
 __wait_for_common+0x2e7/0x4c0 kernel/sched/completion.c:121
 wait_for_common kernel/sched/completion.c:132 [inline]
 wait_for_completion_state+0x1c/0x40 kernel/sched/completion.c:269
 coredump_wait fs/coredump.c:534 [inline]
 vfs_coredump+0x80d/0x5570 fs/coredump.c:1197
 get_signal+0x1f2a/0x21e0 kernel/signal.c:3019
 arch_do_signal_or_restart+0x91/0x770 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
 exit_to_user_mode_loop+0x86/0x4a0 kernel/entry/common.c:98
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline]
 do_syscall_64+0x668/0xf80 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f994879af39
RSP: 002b:00007f99497010e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007f9948a06098 RCX: 00007f994879af39
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f9948a0609c
RBP: 00007f9948a06090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f9948a06128 R14: 00007ffd4eff3890 R15: 00007ffd4eff3978
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/30:
 #0: ffffffff8e5ce2e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
 #0: ffffffff8e5ce2e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
 #0: ffffffff8e5ce2e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775
2 locks held by getty/5581:
 #0: ffff888037b420a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x1500 drivers/tty/n_tty.c:2211
1 lock held by syz.0.17/6433:
1 lock held by syz.1.18/6456:
1 lock held by syz.2.19/6480:
5 locks held by syz.3.20/6510:
1 lock held by syz.4.21/6540:
1 lock held by syz.5.22/6569:
2 locks held by syz.6.23/6606:
1 lock held by syz.7.24/6637:

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x1d7/0x230 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline]
 __sys_info lib/sys_info.c:157 [inline]
 sys_info+0x141/0x190 lib/sys_info.c:165
 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
 watchdog+0xd25/0x1050 kernel/hung_task.c:515
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 6480 Comm: syz.2.19 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:memset_orig+0x3a/0xb0 arch/x86/lib/memset_64.S:71
Code: 01 48 0f af c1 41 89 f9 41 83 e1 07 75 74 48 89 d1 48 c1 e9 06 74 39 66 0f 1f 84 00 00 00 00 00 48 ff c9 48 89 07 48 89 47 08 <48> 89 47 10 48 89 47 18 48 89 47 20 48 89 47 28 48 89 47 30 48 89
RSP: 0018:ffffc90002e77028 EFLAGS: 00000206
RAX: 0000000000000000 RBX: ffffc90002e77240 RCX: 0000000000000024
RDX: 0000000000001000 RSI: 0000000000000000 RDI: ffff88805e0546c0
RBP: 0000000000001000 R08: 0000000000000001 R09: 0000000000000000
R10: ffff88805e054000 R11: 0000000000000000 R12: dffffc0000000000
R13: ffffc90002e77248 R14: 0000000000001000 R15: 0000000000000000
FS:  00007fd2a88bb6c0(0000) GS:ffff88812472f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555882e94e8 CR3: 000000007846e000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 zero_to_iter lib/iov_iter.c:461 [inline]
 iterate_kvec include/linux/iov_iter.h:86 [inline]
 iterate_and_advance2 include/linux/iov_iter.h:308 [inline]
 iterate_and_advance include/linux/iov_iter.h:330 [inline]
 iov_iter_zero+0x9bd/0x15b0 lib/iov_iter.c:467
 hugetlbfs_read_iter+0x6e3/0x8c0 fs/hugetlbfs/inode.c:277
 __kernel_read+0x397/0xac0 fs/read_write.c:532
 integrity_kernel_read+0x7e/0xb0 security/integrity/iint.c:28
 ima_calc_file_hash_tfm+0x25e/0x350 security/integrity/ima/ima_crypto.c:480
 ima_calc_file_shash security/integrity/ima/ima_crypto.c:511 [inline]
 ima_calc_file_hash+0x18c/0x480 security/integrity/ima/ima_crypto.c:568
 ima_collect_measurement+0x887/0xa40 security/integrity/ima/ima_api.c:295
 process_measurement+0xdfe/0x2350 security/integrity/ima/ima_main.c:407
 ima_file_mmap+0x1c4/0x1f0 security/integrity/ima/ima_main.c:505
 security_mmap_file+0x278/0x9b0 security/security.c:2504
 vm_mmap_pgoff+0xec/0x470 mm/util.c:575
 ksys_mmap_pgoff+0x273/0x650 mm/mmap.c:605
 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:89 [inline]
 __se_sys_mmap arch/x86/kernel/sys_x86_64.c:82 [inline]
 __x64_sys_mmap+0x125/0x190 arch/x86/kernel/sys_x86_64.c:82
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd2a799af39
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fd2a88bb028 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007fd2a7c05fa0 RCX: 00007fd2a799af39
RDX: 00004000000000df RSI: 0000004000000001 RDI: 0000000000000008
RBP: 00007fd2a7a2fee0 R08: ffffffffffffffff R09: 0000300000000000
R10: 0000000000040eb1 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd2a7c06038 R14: 00007fd2a7c05fa0 R15: 00007fff04aad838
 </TASK>


Tested on:

commit:         113ae7b4 Merge tag 'hwmon-for-v7.0-rc5' of git://git.k..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=13e2ccba580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=c91defb609dfc805
dashboard link: https://syzkaller.appspot.com/bug?extid=6ed94e81a1492fe1d512
compiler:       gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44
patch:          https://syzkaller.appspot.com/x/patch.diff?x=1082ccba580000

Re: [syzbot] [kernel?] INFO: task hung in vfs_coredump (2)

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-by: syzbot+6ed94e81a1492fe1d512@syzkaller.appspotmail.com
Tested-by: syzbot+6ed94e81a1492fe1d512@syzkaller.appspotmail.com

Tested on:

commit:         113ae7b4 Merge tag 'hwmon-for-v7.0-rc5' of git://git.k..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=164966da580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=c91defb609dfc805
dashboard link: https://syzkaller.appspot.com/bug?extid=6ed94e81a1492fe1d512
compiler:       gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44
patch:          https://syzkaller.appspot.com/x/patch.diff?x=10b166da580000

Note: testing is done by a robot and is best-effort only.