Hello, syzbot found the following issue on: HEAD commit: dad9774deaf1 Merge tag 'timers-urgent-2023-06-21' of git:/.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=1682f600a80000 kernel config: https://syzkaller.appspot.com/x/.config?x=2cbd298d0aff1140 dashboard link: https://syzkaller.appspot.com/bug?extid=fb8d39ebb665f80c2ec1 compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=17effe1f280000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=14972500a80000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/fd1a285f59ed/disk-dad9774d.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/3121ad3d6486/vmlinux-dad9774d.xz kernel image: https://storage.googleapis.com/syzbot-assets/6a57f0b6184a/bzImage-dad9774d.xz mounted in repro: https://storage.googleapis.com/syzbot-assets/c4a7e9030518/mount_1.gz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+fb8d39ebb665f80c2ec1@xxxxxxxxxxxxxxxxxxxxxxxxx BUG: unable to handle page fault for address: fffff5200002af99 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: 0000 [#1] PREEMPT SMP KASAN CPU: 1 PID: 4993 Comm: syz-executor193 Not tainted 6.4.0-rc7-syzkaller-00072-gdad9774deaf1 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023 RIP: 0010:hlist_move_list include/linux/list.h:1029 [inline] RIP: 0010:collect_expired_timers+0x13b/0x200 kernel/time/timer.c:1772 Code: 49 89 45 00 48 89 44 24 10 74 29 e8 bf 21 11 00 48 8b 44 24 10 48 b9 00 00 00 00 00 fc ff df 48 8d 78 08 48 89 fa 48 c1 ea 03 <80> 3c 0a 00 75 7a 4c 89 68 08 e8 96 21 11 00 4d 89 fd 49 c7 04 24 RSP: 0018:ffffc900001e0e20 EFLAGS: 00010016 RAX: ffffc90000157cc0 RBX: 0000000000000000 RCX: dffffc0000000000 RDX: 1ffff9200002af99 RSI: ffffffff81732551 RDI: ffffc90000157cc8 RBP: 00000000ffff9b50 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: ffff8880b993cf98 R12: ffff8880b99297e0 R13: ffffc900001e0eb8 R14: ffff8880b9929720 R15: ffffc900001e0ec0 FS: 00005555561173c0(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: fffff5200002af99 CR3: 0000000079098000 CR4: 0000000000350ee0 Call Trace: <IRQ> ---------------- Code disassembly (best guess): 0: 49 89 45 00 mov %rax,0x0(%r13) 4: 48 89 44 24 10 mov %rax,0x10(%rsp) 9: 74 29 je 0x34 b: e8 bf 21 11 00 callq 0x1121cf 10: 48 8b 44 24 10 mov 0x10(%rsp),%rax 15: 48 b9 00 00 00 00 00 movabs $0xdffffc0000000000,%rcx 1c: fc ff df 1f: 48 8d 78 08 lea 0x8(%rax),%rdi 23: 48 89 fa mov %rdi,%rdx 26: 48 c1 ea 03 shr $0x3,%rdx * 2a: 80 3c 0a 00 cmpb $0x0,(%rdx,%rcx,1) <-- trapping instruction 2e: 75 7a jne 0xaa 30: 4c 89 68 08 mov %r13,0x8(%rax) 34: e8 96 21 11 00 callq 0x1121cf 39: 4d 89 fd mov %r15,%r13 3c: 49 rex.WB 3d: c7 .byte 0xc7 3e: 04 24 add $0x24,%al --- 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@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. If the bug is already fixed, 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 change bug's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the bug is a duplicate of another bug, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup