Forwarded: Re: [syzbot] [kvm?] WARNING in __kvm_gpc_refresh (3)

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Subject: Re: [syzbot] [kvm?] WARNING in __kvm_gpc_refresh (3)
Author: phind.uet@xxxxxxxxx

On 9/3/26 12:39, syzbot wrote:
> Hello,
> 
> syzbot has tested the proposed patch but the reproducer is still triggering an issue:
> WARNING in __kvm_gpc_refresh
> 
> ------------[ cut here ]------------
> kvm_is_error_gpa(gpa) == kvm_is_error_hva(uhva)
> WARNING: arch/x86/kvm/../../../virt/kvm/pfncache.c:267 at __kvm_gpc_refresh+0x1992/0x22c0 virt/kvm/pfncache.c:267, CPU#0: syz.0.17/6390
> Modules linked in:
> CPU: 0 UID: 0 PID: 6390 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full)
> Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
> RIP: 0010:__kvm_gpc_refresh+0x1992/0x22c0 virt/kvm/pfncache.c:267
> Code: 00 fc ff df 48 c1 ea 03 80 3c 02 00 0f 85 26 08 00 00 48 8b 04 24 31 db 48 8b a8 10 01 00 00 e9 cf f0 ff ff e8 8f 47 86 00 90 <0f> 0b 90 e9 92 f7 ff ff e8 81 47 86 00 48 85 db 0f 84 e9 ed ff ff
> RSP: 0018:ffffc9000370f250 EFLAGS: 00010293
> RAX: 0000000000000000 RBX: ffffffffffffffff RCX: ffffffff81836719
> RDX: ffff88803418a4c0 RSI: ffffffff81837fd1 RDI: ffff88803418a4c0
> RBP: ffffffffffffff01 R08: 0000000000000000 R09: 0000000000000001
> R10: 0000000000000001 R11: 0000000000000001 R12: ffff888000000000
> R13: ffff888000000001 R14: ffff888000000000 R15: ffffc9000370f468
> FS:  00007fb4a497e6c0(0000) GS:ffff8880d6331000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 000055dccffea00c CR3: 0000000039576000 CR4: 0000000000352ef0
> Call Trace:
>   <TASK>
>   kvm_gpc_refresh+0xc9/0x190 virt/kvm/pfncache.c:382
>   kvm_xen_set_evtchn.part.0+0x168/0x230 arch/x86/kvm/xen.c:1942
>   kvm_xen_set_evtchn arch/x86/kvm/xen.c:2043 [inline]
>   kvm_xen_hvm_evtchn_send+0x22f/0x290 arch/x86/kvm/xen.c:2033
>   kvm_arch_vm_ioctl+0x13ac/0x18d0 arch/x86/kvm/x86.c:7537
>   kvm_vm_ioctl+0x1564/0x4080 virt/kvm/kvm_main.c:5390
>   vfs_ioctl fs/ioctl.c:51 [inline]
>   __do_sys_ioctl fs/ioctl.c:597 [inline]
>   __se_sys_ioctl fs/ioctl.c:583 [inline]
>   __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
>   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: 0033:0x7fb4a3b9aeb9
> 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:00007fb4a497e028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
> RAX: ffffffffffffffda RBX: 00007fb4a3e15fa0 RCX: 00007fb4a3b9aeb9
> RDX: 0000200000000980 RSI: 00000000400caed0 RDI: 0000000000000004
> RBP: 00007fb4a3c08c1f R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
> R13: 00007fb4a3e16038 R14: 00007fb4a3e15fa0 R15: 00007ffe4fe93708
>   </TASK>
> 
> 
> Tested on:
> 
> commit:         a0ae2a25 Add linux-next specific files for 20260306
> git tree:       linux-next
> console output: https://syzkaller.appspot.com/x/log.txt?x=12c3aa02580000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=a2b2e6917734f438
> dashboard link: https://syzkaller.appspot.com/bug?extid=cde12433b6c56f55d9ed
> compiler:       gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44
> 
> Note: no patches were applied.
#syz test:
git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master