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* [syzbot] [kvm-x86?] KASAN: use-after-free Read in kvm_setup_guest_pvclock
@ 2026-06-29 13:06 syzbot
  2026-06-30 20:10 ` syzbot
  0 siblings, 1 reply; 6+ messages in thread
From: syzbot @ 2026-06-29 13:06 UTC (permalink / raw)
  To: bp, dave.hansen, hpa, kvm, linux-kernel, mingo, pbonzini, seanjc,
	syzkaller-bugs, tglx, x86

Hello,

syzbot found the following issue on:

HEAD commit:    dc59e4fea9d8 Linux 7.2-rc1
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=16f1b46e580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=77808e35144e725c
dashboard link: https://syzkaller.appspot.com/bug?extid=fb7c2dd166d3ea63df2a
compiler:       gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/9911e5707540/disk-dc59e4fe.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/bb0af0bc6e42/vmlinux-dc59e4fe.xz
kernel image: https://storage.googleapis.com/syzbot-assets/b7ca0661e875/bzImage-dc59e4fe.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+fb7c2dd166d3ea63df2a@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: use-after-free in kvm_setup_guest_pvclock+0x5bf/0x660 arch/x86/kvm/x86.c:3272
Read of size 4 at addr ffff88804c505320 by task syz.1.5312/25543

CPU: 1 UID: 0 PID: 25543 Comm: syz.1.5312 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/10/2026
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0x13d/0x4b0 mm/kasan/report.c:482
 kasan_report+0xdf/0x1c0 mm/kasan/report.c:595
 kvm_setup_guest_pvclock+0x5bf/0x660 arch/x86/kvm/x86.c:3272
 kvm_guest_time_update+0xa11/0x10b0 arch/x86/kvm/x86.c:3408
 vcpu_enter_guest arch/x86/kvm/x86.c:11149 [inline]
 vcpu_run+0x1cf1/0x5d50 arch/x86/kvm/x86.c:11707
 kvm_arch_vcpu_ioctl_run+0x5b6/0x1890 arch/x86/kvm/x86.c:12062
 kvm_vcpu_ioctl+0x730/0x1700 virt/kvm/kvm_main.c:4470
 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+0x115/0x870 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5deff9ce59
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:00007f5df0dd3028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f5df0216090 RCX: 00007f5deff9ce59
RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000005
RBP: 00007f5df0032e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5df0216128 R14: 00007f5df0216090 R15: 00007ffd2f6378e8
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x200000000 pfn:0x4c505
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 ffffea000145ba48 ffff8880b85414b0 0000000000000000
raw: 0000000200000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 0, migratetype Movable, gfp_mask 0x140dca(GFP_HIGHUSER_MOVABLE|__GFP_ZERO|__GFP_COMP), pid 25531, tgid 25531 (syz.1.5312), ts 1799784670966, free_ts 1801394089155
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1859
 prep_new_page mm/page_alloc.c:1867 [inline]
 get_page_from_freelist+0xf48/0x3530 mm/page_alloc.c:3946
 __alloc_frozen_pages_noprof+0x299/0x2dc0 mm/page_alloc.c:5304
 alloc_pages_mpol+0x1fb/0x540 mm/mempolicy.c:2490
 folio_alloc_mpol_noprof+0x36/0x260 mm/mempolicy.c:2509
 vma_alloc_folio_noprof+0xed/0x1d0 mm/mempolicy.c:2544
 folio_prealloc mm/memory.c:1207 [inline]
 alloc_anon_folio mm/memory.c:5247 [inline]
 do_anonymous_page+0xb2b/0x2080 mm/memory.c:5342
 do_pte_missing mm/memory.c:4564 [inline]
 handle_pte_fault mm/memory.c:6379 [inline]
 __handle_mm_fault+0x1d2c/0x2a00 mm/memory.c:6517
 handle_mm_fault+0x37b/0xa30 mm/memory.c:6686
 do_user_addr_fault+0x5a3/0x12f0 arch/x86/mm/fault.c:1343
 handle_page_fault arch/x86/mm/fault.c:1483 [inline]
 exc_page_fault+0x6f/0xd0 arch/x86/mm/fault.c:1536
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595
page last free pid 25532 tgid 25531 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1406 [inline]
 __free_frozen_pages+0x79f/0x1090 mm/page_alloc.c:2950
 __folio_put+0x3b4/0x5f0 mm/swap.c:112
 folio_put include/linux/mm.h:2124 [inline]
 put_page include/linux/mm.h:2193 [inline]
 kvm_release_page_clean virt/kvm/kvm_main.c:2813 [inline]
 kvm_release_page_clean+0x1dc/0x250 virt/kvm/kvm_main.c:2807
 hva_to_pfn_retry virt/kvm/pfncache.c:246 [inline]
 __kvm_gpc_refresh+0x1a63/0x22d0 virt/kvm/pfncache.c:330
 __kvm_gpc_activate+0x2ab/0x490 virt/kvm/pfncache.c:424
 kvm_gpc_activate_hva+0x73/0xa0 virt/kvm/pfncache.c:444
 kvm_xen_vcpu_set_attr+0xfa0/0x1350 arch/x86/kvm/xen.c:938
 kvm_arch_vcpu_ioctl+0xf98/0x5730 arch/x86/kvm/x86.c:6612
 kvm_vcpu_ioctl+0x8a0/0x1700 virt/kvm/kvm_main.c:4647
 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+0x115/0x870 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff88804c505200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88804c505280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88804c505300: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                               ^
 ffff88804c505380: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88804c505400: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================


---
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 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

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [syzbot] [kvm-x86?] KASAN: use-after-free Read in kvm_setup_guest_pvclock
  2026-06-29 13:06 syzbot
@ 2026-06-30 20:10 ` syzbot
  0 siblings, 0 replies; 6+ messages in thread
From: syzbot @ 2026-06-30 20:10 UTC (permalink / raw)
  To: bp, dave.hansen, hpa, kvm, linux-kernel, mingo, pbonzini, seanjc,
	syzkaller-bugs, tglx, x86

syzbot has found a reproducer for the following issue on:

HEAD commit:    7de6ae9e1220 Add linux-next specific files for 20260629
git tree:       linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=163d19de580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=93f99737ecde604c
dashboard link: https://syzkaller.appspot.com/bug?extid=fb7c2dd166d3ea63df2a
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=1309af41580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=11f28bae580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/a09187a6eb8d/disk-7de6ae9e.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/f0a76dd86b32/vmlinux-7de6ae9e.xz
kernel image: https://storage.googleapis.com/syzbot-assets/864b9d8296e7/bzImage-7de6ae9e.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+fb7c2dd166d3ea63df2a@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: use-after-free in kvm_setup_guest_pvclock+0x439/0x620 arch/x86/kvm/x86.c:1728
Read of size 4 at addr ffff88804d02c320 by task syz.1.180/6591

CPU: 1 UID: 0 PID: 6591 Comm: syz.1.180 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_address_description+0x55/0x1e0 mm/kasan/report.c:378
 print_report+0x58/0x70 mm/kasan/report.c:482
 kasan_report+0x117/0x150 mm/kasan/report.c:595
 kvm_setup_guest_pvclock+0x439/0x620 arch/x86/kvm/x86.c:1728
 kvm_guest_time_update+0xa32/0xe60 arch/x86/kvm/x86.c:1864
 vcpu_enter_guest arch/x86/kvm/x86.c:8038 [inline]
 vcpu_run+0x150d/0x73e0 arch/x86/kvm/x86.c:8596
 kvm_arch_vcpu_ioctl_run+0xe51/0x1960 arch/x86/kvm/x86.c:8929
 kvm_vcpu_ioctl+0xa64/0xfe0 virt/kvm/kvm_main.c:4470
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl+0xff/0x170 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbebb04ce59
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:00007fbeba68d028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fbebb2c6090 RCX: 00007fbebb04ce59
RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000005
RBP: 00007fbebb0e2e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fbebb2c6128 R14: 00007fbebb2c6090 R15: 00007ffefb5754e8
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x200000000 pfn:0x4d02c
flags: 0x80000000000000(node=0|zone=1)
raw: 0080000000000000 ffffea000159c008 ffff8880b8642f70 0000000000000000
raw: 0000000200000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 0, migratetype Movable, gfp_mask 0x140dca(GFP_HIGHUSER_MOVABLE|__GFP_ZERO|__GFP_COMP), pid 6589, tgid 6589 (syz.1.180), ts 149074813359
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1861
 prep_new_page mm/page_alloc.c:1869 [inline]
 get_page_from_freelist+0x264c/0x26c0 mm/page_alloc.c:3949
 __alloc_frozen_pages_noprof+0x1a6/0x390 mm/page_alloc.c:5322
 alloc_pages_mpol+0xce/0x280 mm/mempolicy.c:2490
 folio_alloc_mpol_noprof+0x3b/0x1e0 mm/mempolicy.c:2509
 vma_alloc_folio_noprof+0xe1/0x1e0 mm/mempolicy.c:2544
 folio_prealloc mm/memory.c:-1 [inline]
 alloc_anon_folio mm/memory.c:5247 [inline]
 do_anonymous_page mm/memory.c:5342 [inline]
 do_pte_missing+0x835/0x28f0 mm/memory.c:4564
 handle_pte_fault mm/memory.c:6379 [inline]
 __handle_mm_fault mm/memory.c:6517 [inline]
 handle_mm_fault+0xe0b/0x1520 mm/memory.c:6686
 do_user_addr_fault+0xa4d/0x1340 arch/x86/mm/fault.c:1343
 handle_page_fault arch/x86/mm/fault.c:1483 [inline]
 exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1536
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595
page last free pid 6590 tgid 6589 ts 149102566230 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1408 [inline]
 __free_frozen_pages+0x10de/0x11c0 mm/page_alloc.c:2952
 __folio_put+0x30f/0x3c0 mm/swap.c:112
 hva_to_pfn_retry virt/kvm/pfncache.c:246 [inline]
 __kvm_gpc_refresh+0x1277/0x1710 virt/kvm/pfncache.c:330
 __kvm_gpc_activate+0x289/0x3b0 virt/kvm/pfncache.c:424
 kvm_xen_vcpu_set_attr+0x1d3/0x1190 arch/x86/kvm/xen.c:938
 kvm_arch_vcpu_ioctl+0x1467/0x23f0 arch/x86/kvm/x86.c:3815
 kvm_vcpu_ioctl+0x7e6/0xfe0 virt/kvm/kvm_main.c:4647
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl+0xff/0x170 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff88804d02c200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88804d02c280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88804d02c300: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                               ^
 ffff88804d02c380: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88804d02c400: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================


---
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.

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [syzbot] [kvm-x86?] KASAN: use-after-free Read in kvm_setup_guest_pvclock
       [not found] <DK3EXQESFKHR.1JMHKZ0ADMVVR@igalia.com>
@ 2026-07-20 13:53 ` syzbot
  0 siblings, 0 replies; 6+ messages in thread
From: syzbot @ 2026-07-20 13:53 UTC (permalink / raw)
  To: halves, linux-kernel, syzkaller-bugs

Hello,

syzbot tried to test the proposed patch but the build/boot failed:

0000b4600000-0x00000000b8600000] (64MB)
[    6.255166][    T1] ACPI: bus type thunderbolt registered
[    6.306362][    T1] RAPL PMU: API unit is 2^-32 Joules, 0 fixed counters, 10737418240 ms ovfl timer
[    6.320726][   T70] kworker/u8:4 (70) used greatest stack depth: 27600 bytes left
[    6.392355][    T1] kvm_amd: CPU 0 isn't AMD or Hygon
[    6.392394][    T1] clocksource: tsc: mask: 0xffffffffffffffff max_cycles: 0x1fb63109b96, max_idle_ns: 440795265316 ns
[    6.393087][    T1] clocksource: Switched to clocksource tsc
[    6.393213][   T71] kworker/u8:3 (71) used greatest stack depth: 27344 bytes left
[    6.418119][   T75] kworker/u8:4 (75) used greatest stack depth: 27200 bytes left
[    6.516097][    T1] Initialise system trusted keyrings
[    6.532538][    T1] workingset: timestamp_bits=40 (anon: 35) max_order=21 bucket_order=0 (anon: 0)
[    6.566694][    T1] DLM installed
[    6.592800][    T1] squashfs: version 4.0 (2009/01/31) Phillip Lougher
[    6.625574][    T1] NFS: Registering the id_resolver key type
[    6.625765][    T1] Key type id_resolver registered
[    6.625780][    T1] Key type id_legacy registered
[    6.626561][    T1] nfs4filelayout_init: NFSv4 File Layout Driver Registering...
[    6.626840][    T1] nfs4flexfilelayout_init: NFSv4 Flexfile Layout Driver Registering...
[    6.683834][    T1] smbdirect: subsystem loading...
[    6.716365][    T1] smbdirect: subsystem loaded
[    6.763512][    T1] Key type cifs.spnego registered
[    6.764174][    T1] Key type cifs.idmap registered
[    6.792353][    T1] ntfs3: Enabled Linux POSIX ACLs support
[    6.792365][    T1] ntfs3: Read-only LZX/Xpress compression included
[    6.792747][    T1] jffs2: version 2.2. (NAND) (SUMMARY)  © 2001-2006 Red Hat, Inc.
[    6.799004][    T1] romfs: ROMFS MTD (C) 2007 Red Hat, Inc.
[    6.851007][    T1] QNX4 filesystem 0.2.3 registered.
[    6.851285][    T1] qnx6: QNX6 filesystem 1.0.0 registered.
[    6.853799][    T1] fuse: init (API version 7.45)
[    6.887403][    T1] orangefs_debugfs_init: called with debug mask: :none: :0:
[    6.894486][    T1] orangefs_init: module version upstream loaded
[    6.898940][    T1] JFS: nTxBlock = 8192, nTxLock = 65536
[    6.932174][    T1] SGI XFS with ACLs, security attributes, realtime, quota, no debug enabled
[    6.955145][    T1] 9p: Installing v9fs 9p2000 file system support
[    6.956070][    T1] NILFS version 2 loaded
[    6.956080][    T1] befs: version: 0.9.3
[    6.957362][    T1] ocfs2: Registered cluster interface o2cb
[    6.999664][    T1] ocfs2: Registered cluster interface user
[    7.020743][    T1] OCFS2 User DLM kernel interface loaded
[    7.067258][    T1] gfs2: GFS2 installed
[    7.097413][    T1] ceph: loaded (mds proto 32)
[    7.117915][    T1] NET: Registered PF_ALG protocol family
[    7.120294][    T1] async_tx: api initialized (async)
[    7.120581][    T1] Key type asymmetric registered
[    7.120754][    T1] Asymmetric key parser 'x509' registered
[    7.120812][    T1] Asymmetric key parser 'pkcs8' registered
[    7.121599][    T1] Key type pkcs7_test registered
[    7.125388][    T1] Block layer SCSI generic (bsg) driver version 0.4 loaded (major 239)
[    7.176102][    T1] io scheduler mq-deadline registered
[    7.176126][    T1] io scheduler kyber registered
[    7.176786][    T1] io scheduler bfq registered
[    7.184322][    T1] raid6: skipped pq benchmark and selected avx2x4
[    7.222671][  T151] kworker/u8:3 (151) used greatest stack depth: 26912 bytes left
[    7.246411][  T156] kworker/u8:5 (156) used greatest stack depth: 26048 bytes left
[    7.267490][    T1] input: Power Button as /devices/platform/LNXPWRBN:00/input/input0
[    7.274296][    T1] ACPI: button: Power Button [PWRF]
[    7.283915][    T1] input: Sleep Button as /devices/platform/LNXSLPBN:00/input/input1
[    7.290898][    T1] ACPI: button: Sleep Button [SLPF]
[    7.344578][    T1] ioatdma: Intel(R) QuickData Technology Driver 5.00
[    7.411368][   T10] ACPI: \_SB_.LNKC: Enabled at IRQ 11
[    7.411566][   T10] virtio-pci 0000:00:03.0: virtio_pci: leaving for legacy driver
[    7.480603][   T10] ACPI: \_SB_.LNKD: Enabled at IRQ 10
[    7.480814][   T10] virtio-pci 0000:00:04.0: virtio_pci: leaving for legacy driver
[    7.540509][   T10] ACPI: \_SB_.LNKB: Enabled at IRQ 10
[    7.540693][   T10] virtio-pci 0000:00:06.0: virtio_pci: leaving for legacy driver
[    7.589579][   T10] virtio-pci 0000:00:07.0: virtio_pci: leaving for legacy driver
[    8.845365][    T1] N_HDLC line discipline registered with maxframe=4096
[    8.848528][    T1] Serial: 8250/16550 driver, 4 ports, IRQ sharing enabled
[    8.888282][    T1] 00:02: ttyS0 I/O:0x3f8 (irq = 4, base_baud = 115200) is a 16550A
[    8.932129][    T1] 00:03: ttyS1 I/O:0x2f8 (irq = 3, base_baud = 115200) is a 16550A
[    8.975973][    T1] 00:04: ttyS2 I/O:0x3e8 (irq = 6, base_baud = 115200) is a 16550A
[    9.048379][    T1] 00:05: ttyS3 I/O:0x2e8 (irq = 7, base_baud = 115200) is a 16550A
[    9.136987][    T1] Non-volatile memory driver v1.3
[    9.209627][    T1] usbcore: registered new interface driver xillyusb
[    9.232020][    T1] ACPI: bus type drm_connector registered
[    9.265590][    T1] [drm] Initialized vgem 1.0.0 for vgem on minor 0
[    9.287444][    T1] ------------[ cut here ]------------
[    9.287465][    T1] [PLANE:35:plane-0] pixel format with alpha exposed but blend mode not setup
[    9.287490][    T1] WARNING: drivers/gpu/drm/drm_mode_config.c:873 at drm_mode_config_validate+0x1c6d/0x1e60, CPU#1: swapper/0/1
[    9.287615][    T1] Modules linked in:
[    9.287649][    T1] CPU: 1 UID: 0 PID: 1 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
[    9.287667][    T1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/25/2026
[    9.287727][    T1] RIP: 0010:drm_mode_config_validate+0x1cae/0x1e60
[    9.287763][    T1] Code: 0f 85 ae 00 00 00 4d 8d 77 10 8b 6d 00 4c 89 f0 48 c1 e8 03 80 3c 18 00 74 08 4c 89 f7 e8 fa b0 be fc 49 8b 16 4c 89 ef 89 ee <67> 48 0f b9 3a eb 05 e8 d6 55 52 fc 49 bd 00 00 00 00 00 fc ff df
[    9.287786][    T1] RSP: 0000:ffffc90000067810 EFLAGS: 00010246
[    9.287807][    T1] RAX: 1ffff11004d00408 RBX: dffffc0000000000 RCX: ffff88801c6e5d00
[    9.287824][    T1] RDX: ffff8880263f9dc0 RSI: 0000000000000023 RDI: ffffffff8fd964c0
[    9.287840][    T1] RBP: 0000000000000023 R08: 0000000000000000 R09: 0000000000000000
[    9.287854][    T1] R10: dffffc0000000000 R11: fffffbfff1f9c610 R12: dffffc0000000000
[    9.287871][    T1] R13: ffffffff8fd964c0 R14: ffff888026802040 R15: ffff888026802030
[    9.287888][    T1] FS:  0000000000000000(0000) GS:ffff888125b69000(0000) knlGS:0000000000000000
[    9.287906][    T1] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    9.287923][    T1] CR2: 0000000000000000 CR3: 000000000e1b0000 CR4: 00000000003526f0
[    9.287942][    T1] Call Trace:
[    9.287957][    T1]  <TASK>
[    9.287982][    T1]  ? debugfs_create_file_full+0x3f/0x60
[    9.288026][    T1]  drm_dev_register+0x7f/0xd80
[    9.288197][    T1]  vkms_create+0x40d/0x4f0
[    9.288232][    T1]  ? __pfx_vkms_init+0x10/0x10
[    9.288272][    T1]  vkms_init+0x57/0x80
[    9.288307][    T1]  do_one_initcall+0x250/0x870
[    9.288334][    T1]  ? __pfx_vkms_init+0x10/0x10
[    9.288371][    T1]  ? __pfx_do_one_initcall+0x10/0x10
[    9.288396][    T1]  ? ktime_get+0x1f5/0x220
[    9.288430][    T1]  ? clockevents_program_event+0x491/0x630
[    9.288459][    T1]  ? __pfx___schedule+0x10/0x10
[    9.288513][    T1]  ? irqentry_exit+0x218/0x8f0
[    9.288544][    T1]  ? lockdep_hardirqs_on+0x7a/0x110
[    9.288579][    T1]  ? irqentry_exit+0x218/0x8f0
[    9.288612][    T1]  ? trace_irq_disable+0x3b/0x140
[    9.288664][    T1]  ? next_arg+0x4a0/0x5e0
[    9.288690][    T1]  ? parameq+0x14d/0x170
[    9.288724][    T1]  ? parse_args+0x9c3/0xad0
[    9.288771][    T1]  ? trace_kmalloc+0x2a/0xf0
[    9.288803][    T1]  ? rcu_is_watching+0x15/0xb0
[    9.288831][    T1]  do_initcall_level+0x10a/0x1a0
[    9.288860][    T1]  ? kernel_init+0x22/0x1d0
[    9.288886][    T1]  do_initcalls+0x59/0xa0
[    9.288913][    T1]  kernel_init_freeable+0x29d/0x3e0
[    9.288939][    T1]  ? __pfx_kernel_init+0x10/0x10
[    9.288967][    T1]  kernel_init+0x22/0x1d0
[    9.288993][    T1]  ? __pfx_kernel_init+0x10/0x10
[    9.289018][    T1]  ret_from_fork+0x514/0xb70
[    9.289072][    T1]  ? __pfx_ret_from_fork+0x10/0x10
[    9.289099][    T1]  ? __switch_to+0xc89/0x1420
[    9.289217][    T1]  ? __pfx_kernel_init+0x10/0x10
[    9.289246][    T1]  ret_from_fork_asm+0x1a/0x30
[    9.289296][    T1]  </TASK>
[    9.289319][    T1] Kernel panic - not syncing: kernel: panic_on_warn set ...
[    9.289336][    T1] CPU: 1 UID: 0 PID: 1 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
[    9.289363][    T1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/25/2026
[    9.289376][    T1] Call Trace:
[    9.289394][    T1]  <TASK>
[    9.289403][    T1]  vpanic+0x56c/0xa60
[    9.289437][    T1]  ? __pfx__printk+0x10/0x10
[    9.289460][    T1]  ? __pfx_vpanic+0x10/0x10
[    9.289491][    T1]  ? is_bpf_text_address+0x292/0x2b0
[    9.289513][    T1]  ? is_bpf_text_address+0x26/0x2b0
[    9.289541][    T1]  panic+0xc5/0xd0
[    9.289574][    T1]  ? __pfx_panic+0x10/0x10
[    9.289615][    T1]  ? ret_from_fork_asm+0x1a/0x30
[    9.289646][    T1]  __warn+0x315/0x4c0
[    9.289676][    T1]  ? drm_mode_config_validate+0x1c6d/0x1e60
[    9.289707][    T1]  ? drm_mode_config_validate+0x1c6d/0x1e60
[    9.289735][    T1]  __report_bug+0x276/0x570
[    9.289773][    T1]  ? drm_mode_config_validate+0x1c6d/0x1e60
[    9.289802][    T1]  ? __pfx___report_bug+0x10/0x10
[    9.289844][    T1]  ? _raw_spin_unlock_irqrestore+0x30/0x80
[    9.289879][    T1]  ? lockdep_hardirqs_on+0x7a/0x110
[    9.289914][    T1]  ? rt_mutex_slowunlock+0x4ee/0xa20
[    9.289945][    T1]  report_bug_entry+0x19a/0x290
[    9.289981][    T1]  ? drm_mode_config_validate+0x1cae/0x1e60
[    9.290008][    T1]  ? drm_mode_config_validate+0x1cb3/0x1e60
[    9.290042][    T1]  handle_bug+0xce/0x200
[    9.290067][    T1]  exc_invalid_op+0x1a/0x50
[    9.290090][    T1]  asm_exc_invalid_op+0x1a/0x20
[    9.290113][    T1] RIP: 0010:drm_mode_config_validate+0x1cae/0x1e60
[    9.290142][    T1] Code: 0f 85 ae 00 00 00 4d 8d 77 10 8b 6d 00 4c 89 f0 48 c1 e8 03 80 3c 18 00 74 08 4c 89 f7 e8 fa b0 be fc 49 8b 16 4c 89 ef 89 ee <67> 48 0f b9 3a eb 05 e8 d6 55 52 fc 49 bd 00 00 00 00 00 fc ff df
[    9.290161][    T1] RSP: 0000:ffffc90000067810 EFLAGS: 00010246
[    9.290181][    T1] RAX: 1ffff11004d00408 RBX: dffffc0000000000 RCX: ffff88801c6e5d00
[    9.290198][    T1] RDX: ffff8880263f9dc0 RSI: 0000000000000023 RDI: ffffffff8fd964c0
[    9.290213][    T1] RBP: 0000000000000023 R08: 0000000000000000 R09: 0000000000000000
[    9.290226][    T1] R10: dffffc0000000000 R11: fffffbfff1f9c610 R12: dffffc0000000000
[    9.290242][    T1] R13: ffffffff8fd964c0 R14: ffff888026802040 R15: ffff888026802030
[    9.290303][    T1]  ? debugfs_create_file_full+0x3f/0x60
[    9.290342][    T1]  drm_dev_register+0x7f/0xd80
[    9.290372][    T1]  vkms_create+0x40d/0x4f0
[    9.290405][    T1]  ? __pfx_vkms_init+0x10/0x10
[    9.290438][    T1]  vkms_init+0x57/0x80
[    9.290473][    T1]  do_one_initcall+0x250/0x870
[    9.290498][    T1]  ? __pfx_vkms_init+0x10/0x10
[    9.290532][    T1]  ? __pfx_do_one_initcall+0x10/0x10
[    9.290654][    T1]  ? ktime_get+0x1f5/0x220
[    9.290683][    T1]  ? clockevents_program_event+0x491/0x630
[    9.290707][    T1]  ? __pfx___schedule+0x10/0x10
[    9.290745][    T1]  ? irqentry_exit+0x218/0x8f0
[    9.290776][    T1]  ? lockdep_hardirqs_on+0x7a/0x110
[    9.290811][    T1]  ? irqentry_exit+0x218/0x8f0
[    9.290843][    T1]  ? trace_irq_disable+0x3b/0x140
[    9.290894][    T1]  ? next_arg+0x4a0/0x5e0
[    9.290917][    T1]  ? parameq+0x14d/0x170
[    9.290951][    T1]  ? parse_args+0x9c3/0xad0
[    9.290998][    T1]  ? trace_kmalloc+0x2a/0xf0
[    9.291070][    T1]  ? rcu_is_watching+0x15/0xb0
[    9.291100][    T1]  do_initcall_level+0x10a/0x1a0
[    9.291288][    T1]  ? kernel_init+0x22/0x1d0
[    9.291320][    T1]  do_initcalls+0x59/0xa0
[    9.291359][    T1]  kernel_init_freeable+0x29d/0x3e0
[    9.291388][    T1]  ? __pfx_kernel_init+0x10/0x10
[    9.291419][    T1]  kernel_init+0x22/0x1d0
[    9.291446][    T1]  ? __pfx_kernel_init+0x10/0x10
[    9.291482][    T1]  ret_from_fork+0x514/0xb70
[    9.291516][    T1]  ? __pfx_ret_from_fork+0x10/0x10
[    9.291545][    T1]  ? __switch_to+0xc89/0x1420
[    9.291569][    T1]  ? __pfx_kernel_init+0x10/0x10
[    9.291596][    T1]  ret_from_fork_asm+0x1a/0x30
[    9.291636][    T1]  </TASK>
[    9.291899][    T1] Kernel Offset: disabled


syzkaller build log:
go env (err=<nil>)
AR='ar'
CC='gcc'
CGO_CFLAGS='-O2 -g'
CGO_CPPFLAGS=''
CGO_CXXFLAGS='-O2 -g'
CGO_ENABLED='1'
CGO_FFLAGS='-O2 -g'
CGO_LDFLAGS='-O2 -g'
CXX='g++'
GCCGO='gccgo'
GO111MODULE='auto'
GOAMD64='v1'
GOARCH='amd64'
GOAUTH='netrc'
GOBIN=''
GOCACHE='/syzkaller/.cache/go-build'
GOCACHEPROG=''
GODEBUG=''
GOENV='/syzkaller/.config/go/env'
GOEXE=''
GOEXPERIMENT=''
GOFIPS140='off'
GOFLAGS=''
GOGCCFLAGS='-fPIC -m64 -pthread -Wl,--no-gc-sections -fmessage-length=0 -ffile-prefix-map=/tmp/go-build721356953=/tmp/go-build -gno-record-gcc-switches'
GOHOSTARCH='amd64'
GOHOSTOS='linux'
GOINSECURE=''
GOMOD='/syzkaller/jobs-2/linux/gopath/src/github.com/google/syzkaller/go.mod'
GOMODCACHE='/syzkaller/jobs-2/linux/gopath/pkg/mod'
GONOPROXY=''
GONOSUMDB=''
GOOS='linux'
GOPATH='/syzkaller/jobs-2/linux/gopath'
GOPRIVATE=''
GOPROXY='https://proxy.golang.org,direct'
GOROOT='/usr/local/go'
GOSUMDB='sum.golang.org'
GOTELEMETRY='local'
GOTELEMETRYDIR='/syzkaller/.config/go/telemetry'
GOTMPDIR=''
GOTOOLCHAIN='auto'
GOTOOLDIR='/usr/local/go/pkg/tool/linux_amd64'
GOVCS=''
GOVERSION='go1.26.0'
GOWORK=''
PKG_CONFIG='pkg-config'

git status (err=<nil>)
HEAD detached at 00e8b0fd0d
nothing to commit, working tree clean


tput: No value for $TERM and no -T specified
tput: No value for $TERM and no -T specified
Makefile:31: run command via tools/syz-env for best compatibility, see:
Makefile:32: https://github.com/google/syzkaller/blob/master/docs/contributing.md#using-syz-env
go list -f '{{.Stale}}' -ldflags="-s -w -X github.com/google/syzkaller/prog.GitRevision=00e8b0fd0d17bb06fe23c0e743356351ada78c22 -X github.com/google/syzkaller/prog.gitRevisionDate=20260630-130833"  ./sys/syz-sysgen | grep -q false || go install -ldflags="-s -w -X github.com/google/syzkaller/prog.GitRevision=00e8b0fd0d17bb06fe23c0e743356351ada78c22 -X github.com/google/syzkaller/prog.gitRevisionDate=20260630-130833"  ./sys/syz-sysgen
make .descriptions
tput: No value for $TERM and no -T specified
tput: No value for $TERM and no -T specified
Makefile:31: run command via tools/syz-env for best compatibility, see:
Makefile:32: https://github.com/google/syzkaller/blob/master/docs/contributing.md#using-syz-env
bin/syz-sysgen
touch .descriptions
GOOS=linux GOARCH=amd64 go build -ldflags="-s -w -X github.com/google/syzkaller/prog.GitRevision=00e8b0fd0d17bb06fe23c0e743356351ada78c22 -X github.com/google/syzkaller/prog.gitRevisionDate=20260630-130833"  -o ./bin/linux_amd64/syz-execprog github.com/google/syzkaller/tools/syz-execprog
mkdir -p ./bin/linux_amd64
g++ -o ./bin/linux_amd64/syz-executor executor/executor.cc \
	-m64 -O2 -pthread -Wall -Werror -Wparentheses -Wunused-const-variable -Wframe-larger-than=16384 -Wno-stringop-overflow -Wno-array-bounds -Wno-format-overflow -Wno-unused-but-set-variable -Wno-unused-command-line-argument -static-pie -std=c++17 -I. -Iexecutor/_include   -DGOOS_linux=1 -DGOARCH_amd64=1 \
	-DHOSTGOOS_linux=1 -DGIT_REVISION=\"00e8b0fd0d17bb06fe23c0e743356351ada78c22\"
/usr/bin/ld: /tmp/ccMCDxTH.o: in function `Connection::Connect(char const*, char const*)':
executor.cc:(.text._ZN10Connection7ConnectEPKcS1_[_ZN10Connection7ConnectEPKcS1_]+0x386): warning: Using 'gethostbyname' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
./tools/check-syzos.sh 2>/dev/null


Error text is too large and was truncated, full error text is at:
https://syzkaller.appspot.com/x/error.txt?x=124c32b9580000


Tested on:

commit:         0718283a Add linux-next specific files for 20260717
git tree:       linux-next
kernel config:  https://syzkaller.appspot.com/x/.config?x=c45dee6227f09fbb
dashboard link: https://syzkaller.appspot.com/bug?extid=fb7c2dd166d3ea63df2a
compiler:       Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
patch:          https://syzkaller.appspot.com/x/patch.diff?x=15f362b9580000


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [syzbot] [kvm-x86?] KASAN: use-after-free Read in kvm_setup_guest_pvclock
       [not found] <DK3GW1EZ10DD.19P93MSB49ISS@igalia.com>
@ 2026-07-20 15:22 ` syzbot
  0 siblings, 0 replies; 6+ messages in thread
From: syzbot @ 2026-07-20 15:22 UTC (permalink / raw)
  To: halves, linux-kernel, syzkaller-bugs

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
lost connection to test machine



Tested on:

commit:         1590cf03 Linux 7.2-rc4
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=159ee2b9580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=337c29be5df8a447
dashboard link: https://syzkaller.appspot.com/bug?extid=fb7c2dd166d3ea63df2a
compiler:       Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
patch:          https://syzkaller.appspot.com/x/patch.diff?x=1021b789580000


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [syzbot] [kvm-x86?] KASAN: use-after-free Read in kvm_setup_guest_pvclock
       [not found] <DK4AP9HEJ2ZC.13A6XWLH6AK6B@igalia.com>
@ 2026-07-21 14:40 ` syzbot
  0 siblings, 0 replies; 6+ messages in thread
From: syzbot @ 2026-07-21 14:40 UTC (permalink / raw)
  To: halves, linux-kernel, syzkaller-bugs

Hello,

syzbot tried to test the proposed patch but the build/boot failed:

 0000:00:00.0: Limiting direct PCI/PCI transfers
[    4.569474][    T1] PCI: CLS 0 bytes, default 64
[    4.571889][    T1] PCI-DMA: Using software bounce buffering for IO (SWIOTLB)
[    4.571911][    T1] software IO TLB: mapped [mem 0x00000000b4600000-0x00000000b8600000] (64MB)
[    4.576668][    T1] ACPI: bus type thunderbolt registered
[    4.604809][   T69] kworker/u8:4 (69) used greatest stack depth: 27824 bytes left
[    4.605349][    T1] RAPL PMU: API unit is 2^-32 Joules, 0 fixed counters, 10737418240 ms ovfl timer
[    4.667843][   T68] kworker/u8:3 (68) used greatest stack depth: 27600 bytes left
[    4.693093][    T1] kvm_amd: CPU 0 isn't AMD or Hygon
[    4.693126][    T1] clocksource: tsc: mask: 0xffffffffffffffff max_cycles: 0x1fb7086095e, max_idle_ns: 440795277026 ns
[    4.693805][    T1] clocksource: Switched to clocksource tsc
[    4.735937][   T78] kworker/u8:1 (78) used greatest stack depth: 27240 bytes left
[    4.775502][    T1] Initialise system trusted keyrings
[    4.776914][   T94] kworker/u8:4 (94) used greatest stack depth: 26856 bytes left
[    4.778809][    T1] workingset: timestamp_bits=40 (anon: 35) max_order=21 bucket_order=0 (anon: 0)
[    4.794347][    T1] DLM installed
[    4.803270][    T1] squashfs: version 4.0 (2009/01/31) Phillip Lougher
[    4.820766][    T1] NFS: Registering the id_resolver key type
[    4.820934][    T1] Key type id_resolver registered
[    4.820948][    T1] Key type id_legacy registered
[    4.821314][    T1] nfs4filelayout_init: NFSv4 File Layout Driver Registering...
[    4.821516][    T1] nfs4flexfilelayout_init: NFSv4 Flexfile Layout Driver Registering...
[    4.828086][    T1] smbdirect: subsystem loading...
[    4.842980][    T1] smbdirect: subsystem loaded
[    4.891092][    T1] Key type cifs.spnego registered
[    4.891558][    T1] Key type cifs.idmap registered
[    4.906529][    T1] ntfs3: Enabled Linux POSIX ACLs support
[    4.906543][    T1] ntfs3: Read-only LZX/Xpress compression included
[    4.907114][    T1] jffs2: version 2.2. (NAND) (SUMMARY)  © 2001-2006 Red Hat, Inc.
[    4.911063][    T1] romfs: ROMFS MTD (C) 2007 Red Hat, Inc.
[    4.911761][    T1] QNX4 filesystem 0.2.3 registered.
[    4.911930][    T1] qnx6: QNX6 filesystem 1.0.0 registered.
[    4.913356][    T1] fuse: init (API version 7.45)
[    4.922704][    T1] orangefs_debugfs_init: called with debug mask: :none: :0:
[    4.926315][    T1] orangefs_init: module version upstream loaded
[    4.927651][    T1] JFS: nTxBlock = 8192, nTxLock = 65536
[    4.944092][    T1] SGI XFS with ACLs, security attributes, realtime, quota, no debug enabled
[    4.957411][    T1] 9p: Installing v9fs 9p2000 file system support
[    4.991879][    T1] NILFS version 2 loaded
[    4.991899][    T1] befs: version: 0.9.3
[    4.993486][    T1] ocfs2: Registered cluster interface o2cb
[    4.995705][    T1] ocfs2: Registered cluster interface user
[    5.006868][    T1] OCFS2 User DLM kernel interface loaded
[    5.046841][    T1] gfs2: GFS2 installed
[    5.068429][    T1] ceph: loaded (mds proto 32)
[    5.102190][    T1] NET: Registered PF_ALG protocol family
[    5.103074][    T1] async_tx: api initialized (async)
[    5.103141][    T1] Key type asymmetric registered
[    5.103216][    T1] Asymmetric key parser 'x509' registered
[    5.103231][    T1] Asymmetric key parser 'pkcs8' registered
[    5.103244][    T1] Key type pkcs7_test registered
[    5.105026][    T1] Block layer SCSI generic (bsg) driver version 0.4 loaded (major 239)
[    5.107338][    T1] io scheduler mq-deadline registered
[    5.107356][    T1] io scheduler kyber registered
[    5.107949][    T1] io scheduler bfq registered
[    5.110066][    T1] raid6: skipped pq benchmark and selected avx2x4
[    5.162638][    T1] input: Power Button as /devices/platform/LNXPWRBN:00/input/input0
[    5.164944][    T1] ACPI: button: Power Button [PWRF]
[    5.167933][    T1] input: Sleep Button as /devices/platform/LNXSLPBN:00/input/input1
[    5.172152][    T1] ACPI: button: Sleep Button [SLPF]
[    5.227446][  T156] kworker/u8:3 (156) used greatest stack depth: 26464 bytes left
[    5.249131][  T192] kworker/u8:7 (192) used greatest stack depth: 26184 bytes left
[    5.258909][    T1] ioatdma: Intel(R) QuickData Technology Driver 5.00
[    5.298972][   T10] ACPI: \_SB_.LNKC: Enabled at IRQ 11
[    5.299187][   T10] virtio-pci 0000:00:03.0: virtio_pci: leaving for legacy driver
[    5.343562][   T10] ACPI: \_SB_.LNKD: Enabled at IRQ 10
[    5.343730][   T10] virtio-pci 0000:00:04.0: virtio_pci: leaving for legacy driver
[    5.382813][   T10] ACPI: \_SB_.LNKB: Enabled at IRQ 10
[    5.382940][   T10] virtio-pci 0000:00:06.0: virtio_pci: leaving for legacy driver
[    5.411801][   T10] virtio-pci 0000:00:07.0: virtio_pci: leaving for legacy driver
[    6.372357][    T1] N_HDLC line discipline registered with maxframe=4096
[    6.375656][    T1] Serial: 8250/16550 driver, 4 ports, IRQ sharing enabled
[    6.396359][    T1] 00:02: ttyS0 I/O:0x3f8 (irq = 4, base_baud = 115200) is a 16550A
[    6.424359][    T1] 00:03: ttyS1 I/O:0x2f8 (irq = 3, base_baud = 115200) is a 16550A
[    6.452988][    T1] 00:04: ttyS2 I/O:0x3e8 (irq = 6, base_baud = 115200) is a 16550A
[    6.479183][    T1] 00:05: ttyS3 I/O:0x2e8 (irq = 7, base_baud = 115200) is a 16550A
[    6.531386][    T1] Non-volatile memory driver v1.3
[    6.575265][    T1] usbcore: registered new interface driver xillyusb
[    6.587434][    T1] ACPI: bus type drm_connector registered
[    6.599051][    T1] [drm] Initialized vgem 1.0.0 for vgem on minor 0
[    6.607283][    T1] ------------[ cut here ]------------
[    6.607294][    T1] [PLANE:35:plane-0] pixel format with alpha exposed but blend mode not setup
[    6.607314][    T1] WARNING: drivers/gpu/drm/drm_mode_config.c:873 at drm_mode_config_validate+0x1c6d/0x1e60, CPU#0: swapper/0/1
[    6.607376][    T1] Modules linked in:
[    6.607413][    T1] CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
[    6.607432][    T1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/25/2026
[    6.607449][    T1] RIP: 0010:drm_mode_config_validate+0x1cae/0x1e60
[    6.607476][    T1] Code: 0f 85 ae 00 00 00 4d 8d 77 10 8b 6d 00 4c 89 f0 48 c1 e8 03 80 3c 18 00 74 08 4c 89 f7 e8 9a 8a be fc 49 8b 16 4c 89 ef 89 ee <67> 48 0f b9 3a eb 05 e8 b6 24 52 fc 49 bd 00 00 00 00 00 fc ff df
[    6.607494][    T1] RSP: 0000:ffffc90000067810 EFLAGS: 00010246
[    6.607516][    T1] RAX: 1ffff11004c7f408 RBX: dffffc0000000000 RCX: ffff88801c6e5d00
[    6.607530][    T1] RDX: ffff8880262a51c0 RSI: 0000000000000023 RDI: ffffffff8fd973c0
[    6.607543][    T1] RBP: 0000000000000023 R08: 0000000000000000 R09: 0000000000000000
[    6.607554][    T1] R10: dffffc0000000000 R11: fffffbfff1f9c7f0 R12: dffffc0000000000
[    6.607568][    T1] R13: ffffffff8fd973c0 R14: ffff8880263fa040 R15: ffff8880263fa030
[    6.607582][    T1] FS:  0000000000000000(0000) GS:ffff888125a66000(0000) knlGS:0000000000000000
[    6.607597][    T1] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    6.607608][    T1] CR2: ffff88823ffff000 CR3: 000000000e1b0000 CR4: 00000000003526f0
[    6.607623][    T1] Call Trace:
[    6.607634][    T1]  <TASK>
[    6.607659][    T1]  ? debugfs_create_file_full+0x3f/0x60
[    6.607689][    T1]  drm_dev_register+0x7f/0xd80
[    6.607719][    T1]  vkms_create+0x40d/0x4f0
[    6.607741][    T1]  ? __pfx_vkms_init+0x10/0x10
[    6.607769][    T1]  vkms_init+0x57/0x80
[    6.607791][    T1]  do_one_initcall+0x250/0x870
[    6.607811][    T1]  ? __pfx_vkms_init+0x10/0x10
[    6.607834][    T1]  ? __pfx_do_one_initcall+0x10/0x10
[    6.607867][    T1]  ? __pfx___schedule+0x10/0x10
[    6.607905][    T1]  ? irqentry_exit+0x218/0x8f0
[    6.607926][    T1]  ? lockdep_hardirqs_on+0x7a/0x110
[    6.607947][    T1]  ? irqentry_exit+0x218/0x8f0
[    6.607966][    T1]  ? trace_irq_disable+0x3b/0x140
[    6.608002][    T1]  ? parameq+0x14d/0x170
[    6.608028][    T1]  ? parse_args+0x9c3/0xad0
[    6.608065][    T1]  ? trace_kmalloc+0x2a/0xf0
[    6.608089][    T1]  ? rcu_is_watching+0x15/0xb0
[    6.608111][    T1]  do_initcall_level+0x10a/0x1a0
[    6.608138][    T1]  ? kernel_init+0x22/0x1d0
[    6.608163][    T1]  do_initcalls+0x59/0xa0
[    6.608189][    T1]  kernel_init_freeable+0x29d/0x3e0
[    6.608214][    T1]  ? __pfx_kernel_init+0x10/0x10
[    6.608239][    T1]  kernel_init+0x22/0x1d0
[    6.608262][    T1]  ? __pfx_kernel_init+0x10/0x10
[    6.608284][    T1]  ret_from_fork+0x514/0xb70
[    6.608308][    T1]  ? __pfx_ret_from_fork+0x10/0x10
[    6.608329][    T1]  ? __switch_to+0xc89/0x1420
[    6.608347][    T1]  ? __pfx_kernel_init+0x10/0x10
[    6.608373][    T1]  ret_from_fork_asm+0x1a/0x30
[    6.608405][    T1]  </TASK>
[    6.608426][    T1] Kernel panic - not syncing: kernel: panic_on_warn set ...
[    6.608438][    T1] CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
[    6.608458][    T1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/25/2026
[    6.608467][    T1] Call Trace:
[    6.608474][    T1]  <TASK>
[    6.608481][    T1]  vpanic+0x56c/0xa60
[    6.608512][    T1]  ? __pfx__printk+0x10/0x10
[    6.608530][    T1]  ? __pfx_vpanic+0x10/0x10
[    6.608550][    T1]  ? is_bpf_text_address+0x292/0x2b0
[    6.608567][    T1]  ? is_bpf_text_address+0x26/0x2b0
[    6.608593][    T1]  panic+0xc5/0xd0
[    6.608615][    T1]  ? __pfx_panic+0x10/0x10
[    6.608646][    T1]  ? ret_from_fork_asm+0x1a/0x30
[    6.608671][    T1]  __warn+0x315/0x4c0
[    6.608692][    T1]  ? drm_mode_config_validate+0x1c6d/0x1e60
[    6.608721][    T1]  ? drm_mode_config_validate+0x1c6d/0x1e60
[    6.608745][    T1]  __report_bug+0x276/0x570
[    6.608771][    T1]  ? drm_mode_config_validate+0x1c6d/0x1e60
[    6.608800][    T1]  ? __pfx___report_bug+0x10/0x10
[    6.608826][    T1]  ? _raw_spin_unlock_irqrestore+0x30/0x80
[    6.608848][    T1]  ? lockdep_hardirqs_on+0x7a/0x110
[    6.608871][    T1]  ? rt_mutex_slowunlock+0x4ee/0xa20
[    6.608892][    T1]  report_bug_entry+0x19a/0x290
[    6.608914][    T1]  ? drm_mode_config_validate+0x1cae/0x1e60
[    6.608938][    T1]  ? drm_mode_config_validate+0x1cb3/0x1e60
[    6.608962][    T1]  handle_bug+0xce/0x200
[    6.608985][    T1]  exc_invalid_op+0x1a/0x50
[    6.609007][    T1]  asm_exc_invalid_op+0x1a/0x20
[    6.609025][    T1] RIP: 0010:drm_mode_config_validate+0x1cae/0x1e60
[    6.609050][    T1] Code: 0f 85 ae 00 00 00 4d 8d 77 10 8b 6d 00 4c 89 f0 48 c1 e8 03 80 3c 18 00 74 08 4c 89 f7 e8 9a 8a be fc 49 8b 16 4c 89 ef 89 ee <67> 48 0f b9 3a eb 05 e8 b6 24 52 fc 49 bd 00 00 00 00 00 fc ff df
[    6.609064][    T1] RSP: 0000:ffffc90000067810 EFLAGS: 00010246
[    6.609078][    T1] RAX: 1ffff11004c7f408 RBX: dffffc0000000000 RCX: ffff88801c6e5d00
[    6.609092][    T1] RDX: ffff8880262a51c0 RSI: 0000000000000023 RDI: ffffffff8fd973c0
[    6.609105][    T1] RBP: 0000000000000023 R08: 0000000000000000 R09: 0000000000000000
[    6.609116][    T1] R10: dffffc0000000000 R11: fffffbfff1f9c7f0 R12: dffffc0000000000
[    6.609129][    T1] R13: ffffffff8fd973c0 R14: ffff8880263fa040 R15: ffff8880263fa030
[    6.609167][    T1]  ? debugfs_create_file_full+0x3f/0x60
[    6.609195][    T1]  drm_dev_register+0x7f/0xd80
[    6.609224][    T1]  vkms_create+0x40d/0x4f0
[    6.609245][    T1]  ? __pfx_vkms_init+0x10/0x10
[    6.609267][    T1]  vkms_init+0x57/0x80
[    6.609289][    T1]  do_one_initcall+0x250/0x870
[    6.609309][    T1]  ? __pfx_vkms_init+0x10/0x10
[    6.609332][    T1]  ? __pfx_do_one_initcall+0x10/0x10
[    6.609366][    T1]  ? __pfx___schedule+0x10/0x10
[    6.609396][    T1]  ? irqentry_exit+0x218/0x8f0
[    6.609416][    T1]  ? lockdep_hardirqs_on+0x7a/0x110
[    6.609437][    T1]  ? irqentry_exit+0x218/0x8f0
[    6.609456][    T1]  ? trace_irq_disable+0x3b/0x140
[    6.609493][    T1]  ? parameq+0x14d/0x170
[    6.609516][    T1]  ? parse_args+0x9c3/0xad0
[    6.609516][    T1]  ? trace_kmalloc+0x2a/0xf0
[    6.609516][    T1]  ? rcu_is_watching+0x15/0xb0
[    6.609516][    T1]  do_initcall_level+0x10a/0x1a0
[    6.609516][    T1]  ? kernel_init+0x22/0x1d0
[    6.609516][    T1]  do_initcalls+0x59/0xa0
[    6.609516][    T1]  kernel_init_freeable+0x29d/0x3e0
[    6.609516][    T1]  ? __pfx_kernel_init+0x10/0x10
[    6.609516][    T1]  kernel_init+0x22/0x1d0
[    6.609516][    T1]  ? __pfx_kernel_init+0x10/0x10
[    6.609516][    T1]  ret_from_fork+0x514/0xb70
[    6.609516][    T1]  ? __pfx_ret_from_fork+0x10/0x10
[    6.609516][    T1]  ? __switch_to+0xc89/0x1420
[    6.609516][    T1]  ? __pfx_kernel_init+0x10/0x10
[    6.609516][    T1]  ret_from_fork_asm+0x1a/0x30
[    6.609516][    T1]  </TASK>
[    6.609516][    T1] Kernel Offset: disabled


syzkaller build log:
go env (err=<nil>)
AR='ar'
CC='gcc'
CGO_CFLAGS='-O2 -g'
CGO_CPPFLAGS=''
CGO_CXXFLAGS='-O2 -g'
CGO_ENABLED='1'
CGO_FFLAGS='-O2 -g'
CGO_LDFLAGS='-O2 -g'
CXX='g++'
GCCGO='gccgo'
GO111MODULE='auto'
GOAMD64='v1'
GOARCH='amd64'
GOAUTH='netrc'
GOBIN=''
GOCACHE='/syzkaller/.cache/go-build'
GOCACHEPROG=''
GODEBUG=''
GOENV='/syzkaller/.config/go/env'
GOEXE=''
GOEXPERIMENT=''
GOFIPS140='off'
GOFLAGS=''
GOGCCFLAGS='-fPIC -m64 -pthread -Wl,--no-gc-sections -fmessage-length=0 -ffile-prefix-map=/tmp/go-build3991592182=/tmp/go-build -gno-record-gcc-switches'
GOHOSTARCH='amd64'
GOHOSTOS='linux'
GOINSECURE=''
GOMOD='/syzkaller/jobs/linux/gopath/src/github.com/google/syzkaller/go.mod'
GOMODCACHE='/syzkaller/jobs/linux/gopath/pkg/mod'
GONOPROXY=''
GONOSUMDB=''
GOOS='linux'
GOPATH='/syzkaller/jobs/linux/gopath'
GOPRIVATE=''
GOPROXY='https://proxy.golang.org,direct'
GOROOT='/usr/local/go'
GOSUMDB='sum.golang.org'
GOTELEMETRY='local'
GOTELEMETRYDIR='/syzkaller/.config/go/telemetry'
GOTMPDIR=''
GOTOOLCHAIN='auto'
GOTOOLDIR='/usr/local/go/pkg/tool/linux_amd64'
GOVCS=''
GOVERSION='go1.26.0'
GOWORK=''
PKG_CONFIG='pkg-config'

git status (err=<nil>)
HEAD detached at 00e8b0fd0d
nothing to commit, working tree clean


tput: No value for $TERM and no -T specified
tput: No value for $TERM and no -T specified
Makefile:31: run command via tools/syz-env for best compatibility, see:
Makefile:32: https://github.com/google/syzkaller/blob/master/docs/contributing.md#using-syz-env
go list -f '{{.Stale}}' -ldflags="-s -w -X github.com/google/syzkaller/prog.GitRevision=00e8b0fd0d17bb06fe23c0e743356351ada78c22 -X github.com/google/syzkaller/prog.gitRevisionDate=20260630-130833"  ./sys/syz-sysgen | grep -q false || go install -ldflags="-s -w -X github.com/google/syzkaller/prog.GitRevision=00e8b0fd0d17bb06fe23c0e743356351ada78c22 -X github.com/google/syzkaller/prog.gitRevisionDate=20260630-130833"  ./sys/syz-sysgen
make .descriptions
tput: No value for $TERM and no -T specified
tput: No value for $TERM and no -T specified
Makefile:31: run command via tools/syz-env for best compatibility, see:
Makefile:32: https://github.com/google/syzkaller/blob/master/docs/contributing.md#using-syz-env
bin/syz-sysgen
touch .descriptions
GOOS=linux GOARCH=amd64 go build -ldflags="-s -w -X github.com/google/syzkaller/prog.GitRevision=00e8b0fd0d17bb06fe23c0e743356351ada78c22 -X github.com/google/syzkaller/prog.gitRevisionDate=20260630-130833"  -o ./bin/linux_amd64/syz-execprog github.com/google/syzkaller/tools/syz-execprog
mkdir -p ./bin/linux_amd64
g++ -o ./bin/linux_amd64/syz-executor executor/executor.cc \
	-m64 -O2 -pthread -Wall -Werror -Wparentheses -Wunused-const-variable -Wframe-larger-than=16384 -Wno-stringop-overflow -Wno-array-bounds -Wno-format-overflow -Wno-unused-but-set-variable -Wno-unused-command-line-argument -static-pie -std=c++17 -I. -Iexecutor/_include   -DGOOS_linux=1 -DGOARCH_amd64=1 \
	-DHOSTGOOS_linux=1 -DGIT_REVISION=\"00e8b0fd0d17bb06fe23c0e743356351ada78c22\"
/usr/bin/ld: /tmp/ccOIdA2r.o: in function `Connection::Connect(char const*, char const*)':
executor.cc:(.text._ZN10Connection7ConnectEPKcS1_[_ZN10Connection7ConnectEPKcS1_]+0x386): warning: Using 'gethostbyname' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
./tools/check-syzos.sh 2>/dev/null


Error text is too large and was truncated, full error text is at:
https://syzkaller.appspot.com/x/error.txt?x=10d692b9580000


Tested on:

commit:         3fe08b97 Add linux-next specific files for 20260720
git tree:       linux-next
kernel config:  https://syzkaller.appspot.com/x/.config?x=65d6389adb1eb707
dashboard link: https://syzkaller.appspot.com/bug?extid=fb7c2dd166d3ea63df2a
compiler:       Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8

Note: no patches were applied.

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [syzbot] [kvm-x86?] KASAN: use-after-free Read in kvm_setup_guest_pvclock
       [not found] <DK582SQ6WP0Q.O9P9KPEGWJQ0@igalia.com>
@ 2026-07-22 18:37 ` syzbot
  0 siblings, 0 replies; 6+ messages in thread
From: syzbot @ 2026-07-22 18:37 UTC (permalink / raw)
  To: halves, linux-kernel, syzkaller-bugs

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
lost connection to test machine



Tested on:

commit:         b4515cf4 Add linux-next specific files for 20260722
git tree:       linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=15b78099580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=11d45755069d7236
dashboard link: https://syzkaller.appspot.com/bug?extid=fb7c2dd166d3ea63df2a
compiler:       Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
patch:          https://syzkaller.appspot.com/x/patch.diff?x=16862ab9580000


^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2026-07-22 18:37 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
     [not found] <DK4AP9HEJ2ZC.13A6XWLH6AK6B@igalia.com>
2026-07-21 14:40 ` [syzbot] [kvm-x86?] KASAN: use-after-free Read in kvm_setup_guest_pvclock syzbot
     [not found] <DK582SQ6WP0Q.O9P9KPEGWJQ0@igalia.com>
2026-07-22 18:37 ` syzbot
     [not found] <DK3GW1EZ10DD.19P93MSB49ISS@igalia.com>
2026-07-20 15:22 ` syzbot
     [not found] <DK3EXQESFKHR.1JMHKZ0ADMVVR@igalia.com>
2026-07-20 13:53 ` syzbot
2026-06-29 13:06 syzbot
2026-06-30 20:10 ` syzbot

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