syzbot

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.
faulting far call emulation tainted memory
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WARNING: CPU: 1 PID: 4425 at arch/x86/kvm/x86.c:11290 kvm_arch_vcpu_ioctl_run+0x1c59/0x2390 arch/x86/kvm/x86.c:11290
Modules linked in:
CPU: 1 PID: 4425 Comm: syz.0.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:kvm_arch_vcpu_ioctl_run+0x1c59/0x2390 arch/x86/kvm/x86.c:11290
Code: 45 85 e4 7e 50 e8 b7 09 71 00 49 be 00 00 00 00 00 fc ff df e9 9f f1 ff ff e8 a3 09 71 00 0f 0b e9 5d f1 ff ff e8 97 09 71 00 <0f> 0b e9 87 f1 ff ff e8 8b 09 71 00 e9 4a e6 ff ff e8 81 09 71 00
RSP: 0018:ffffc900034e7c48 EFLAGS: 00010293
RAX: ffffffff810fc6f9 RBX: ffff8880794b8000 RCX: ffff88802dab0000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffff88805daba000 R08: dffffc0000000000 R09: fffffbfff215c468
R10: fffffbfff215c468 R11: 1ffffffff215c467 R12: 1ffff1100f297129
R13: ffff8880794b80d8 R14: dffffc0000000000 R15: 0000000000000001
FS:  000055555a22a500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 00000000779cb000 CR4: 00000000003526e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 kvm_vcpu_ioctl+0x887/0xb80 virt/kvm/kvm_main.c:4122
 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:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7ff54638eba9
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:00007ffd8e51aef8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007ff5465d5fa0 RCX: 00007ff54638eba9
RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000005
RBP: 00007ff546411e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff5465d5fa0 R14: 00007ff5465d5fa0 R15: 0000000000000003
 </TASK>