[v6.1] WARNING in __ftrace_trace_stack

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: fb28aa725e05 Linux 6.1.180
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=15b95499580000
kernel config: https://syzkaller.appspot.com/x/.config?x=31dfefc4a14efea3
dashboard link: https://syzkaller.appspot.com/bug?extid=250d50f4687a0b9010c2
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/9a6fe2a54d0f/disk-fb28aa72.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/742b23a1d931/vmlinux-fb28aa72.xz
kernel image: https://storage.googleapis.com/syzbot-assets/b3f257c16d2e/bzImage-fb28aa72.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+250d50...@syzkaller.appspotmail.com

------------[ cut here ]------------
memcpy: detected field-spanning write (size 96) of single field "&entry->caller" at kernel/trace/trace.c:3091 (size 64)
WARNING: CPU: 1 PID: 4571 at kernel/trace/trace.c:3091 __ftrace_trace_stack+0x3ce/0x530 kernel/trace/trace.c:3091
Modules linked in:
CPU: 1 PID: 4571 Comm: syz.1.58 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:__ftrace_trace_stack+0x3ce/0x530 kernel/trace/trace.c:3091
Code: fe ff ff e8 d4 4f fc ff c6 05 2a c1 86 0c 01 b9 40 00 00 00 48 c7 c7 60 7a 90 8a 4c 89 ee 48 c7 c2 00 92 90 8a e8 02 da c7 ff <0f> 0b e9 25 fe ff ff e8 a6 4f fc ff 48 8b 3c 24 4c 89 f6 e8 5a 88
RSP: 0018:ffffc9000511f0b8 EFLAGS: 00010246
RAX: 4fb0c80ac8a70a00 RBX: ffff8880177ff038 RCX: 0000000000080000
RDX: ffffc9000591a000 RSI: 000000000000a1f8 RDI: 000000000000a1f9
RBP: ffff8880177ff028 R08: ffffc9000511ed47 R09: 1ffff92000a23da8
R10: dffffc0000000000 R11: fffff52000a23da9 R12: ffff8880b8f2b5e0
R13: 0000000000000060 R14: ffff8880177ff024 R15: 00000000000011db
FS: 00007f8b6f7856c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c39fdae CR3: 0000000053434000 CR4: 00000000003526e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
stacktrace_trigger+0xf0/0x140 kernel/trace/trace_events_trigger.c:1545
event_triggers_post_call+0xfd/0x180 kernel/trace/trace_events_trigger.c:126
do_trace_event_raw_event_kvm_hv_stimer_cleanup arch/x86/kvm/trace.h:1357 [inline]
trace_event_raw_event_kvm_hv_stimer_cleanup+0x14b/0x220 arch/x86/kvm/trace.h:1357
trace_kvm_hv_stimer_cleanup arch/x86/kvm/trace.h:1357 [inline]
stimer_cleanup+0x3a7/0x430 arch/x86/kvm/hyperv.c:581
stimer_set_config arch/x86/kvm/hyperv.c:682 [inline]
kvm_hv_set_msr arch/x86/kvm/hyperv.c:1511 [inline]
kvm_hv_set_msr_common+0x1476/0x32a0 arch/x86/kvm/hyperv.c:1672
kvm_set_msr_common+0x843/0x2cb0 arch/x86/kvm/x86.c:3852
vmx_set_msr+0x1438/0x2780 arch/x86/kvm/vmx/vmx.c:2431
__kvm_set_msr+0x2b5/0x5f0 arch/x86/kvm/x86.c:1903
kvm_set_msr_ignored_check arch/x86/kvm/x86.c:1909 [inline]
do_set_msr arch/x86/kvm/x86.c:2227 [inline]
__msr_io arch/x86/kvm/x86.c:4292 [inline]
msr_io arch/x86/kvm/x86.c:4328 [inline]
kvm_arch_vcpu_ioctl+0x1c1b/0x2400 arch/x86/kvm/x86.c:5690
kvm_vcpu_ioctl+0x700/0xc10 virt/kvm/kvm_main.c:4278
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:870 [inline]
__se_sys_ioctl+0xfa/0x170 fs/ioctl.c:856
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f8b6e99e019
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:00007f8b6f785028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f8b6ec25fa0 RCX: 00007f8b6e99e019
RDX: 0000200000000800 RSI: 000000004008ae89 RDI: 0000000000000007
RBP: 00007f8b6ea3500c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8b6ec26038 R14: 00007f8b6ec25fa0 R15: 00007ffed0934e88
</TASK>


---
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[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: fb28aa725e05 Linux 6.1.180
git tree: linux-6.1.y

console output: https://syzkaller.appspot.com/x/log.txt?x=16f18e49580000

kernel config: https://syzkaller.appspot.com/x/.config?x=31dfefc4a14efea3
dashboard link: https://syzkaller.appspot.com/bug?extid=250d50f4687a0b9010c2
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=151c3c99580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=106877b9580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/9a6fe2a54d0f/disk-fb28aa72.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/742b23a1d931/vmlinux-fb28aa72.xz
kernel image: https://storage.googleapis.com/syzbot-assets/b3f257c16d2e/bzImage-fb28aa72.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+250d50...@syzkaller.appspotmail.com

L1TF CPU bug present and SMT on, data leak possible. See CVE-2018-3646 and https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/l1tf.html for details.
------------[ cut here ]------------
memcpy: detected field-spanning write (size 128) of single field "&entry->caller" at kernel/trace/trace.c:3091 (size 64)
WARNING: CPU: 0 PID: 4430 at kernel/trace/trace.c:3091 __ftrace_trace_stack+0x3ce/0x530 kernel/trace/trace.c:3091
Modules linked in:
CPU: 0 PID: 4430 Comm: syz.0.17 Not tainted syzkaller #0

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:__ftrace_trace_stack+0x3ce/0x530 kernel/trace/trace.c:3091
Code: fe ff ff e8 d4 4f fc ff c6 05 2a c1 86 0c 01 b9 40 00 00 00 48 c7 c7 60 7a 90 8a 4c 89 ee 48 c7 c2 00 92 90 8a e8 02 da c7 ff <0f> 0b e9 25 fe ff ff e8 a6 4f fc ff 48 8b 3c 24 4c 89 f6 e8 5a 88

RSP: 0018:ffffc900034578b8 EFLAGS: 00010246
RAX: 9064f39956f2ca00 RBX: ffff8880174c2028 RCX: ffff88807a123c00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000002
RBP: ffff8880174c2018 R08: ffffc90003457547 R09: 1ffff9200068aea8
R10: dffffc0000000000 R11: fffff5200068aea9 R12: ffff8880b8e2b5e0
R13: 0000000000000080 R14: ffff8880174c2010 R15: 000000000000114e
FS: 000055557c512500(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000

CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033

CR2: 0000001b2df24008 CR3: 000000002c2e4000 CR4: 00000000003526f0

DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
stacktrace_trigger+0xf0/0x140 kernel/trace/trace_events_trigger.c:1545
event_triggers_post_call+0xfd/0x180 kernel/trace/trace_events_trigger.c:126
do_trace_event_raw_event_kvm_hv_stimer_cleanup arch/x86/kvm/trace.h:1357 [inline]
trace_event_raw_event_kvm_hv_stimer_cleanup+0x14b/0x220 arch/x86/kvm/trace.h:1357
trace_kvm_hv_stimer_cleanup arch/x86/kvm/trace.h:1357 [inline]
stimer_cleanup+0x3a7/0x430 arch/x86/kvm/hyperv.c:581

kvm_hv_vcpu_uninit+0x4f/0xa0 arch/x86/kvm/hyperv.c:883
kvm_arch_vcpu_destroy+0xba/0x270 arch/x86/kvm/x86.c:12143
kvm_vcpu_destroy virt/kvm/kvm_main.c:495 [inline]
kvm_destroy_vcpus+0xdd/0x250 virt/kvm/kvm_main.c:515
kvm_arch_destroy_vm+0x31a/0x410 arch/x86/kvm/x86.c:12725
kvm_destroy_vm virt/kvm/kvm_main.c:1336 [inline]
kvm_put_kvm+0xdbb/0x1a10 virt/kvm/kvm_main.c:1370
kvm_vm_release+0x42/0x50 virt/kvm/kvm_main.c:1393
__fput+0x20a/0x8b0 fs/file_table.c:320
task_work_run+0x1d0/0x260 kernel/task_work.c:203
resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f8db999e0d9

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:00007fffae095078 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007fffae095160 RCX: 00007f8db999e0d9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00000000000158d1 R08: 0000000000000001 R09: 0000000000000000
R10: 0000001b2d320000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8db9c25fac R14: 00007f8db9c25fa8 R15: 00007f8db9c25fa0
</TASK>


---
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