Hello, syzbot found the following issue on: HEAD commit: 6cd06ab12d1a gup: make the stack expansion warning a bit m.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=13fdf29ca80000 kernel config: https://syzkaller.appspot.com/x/.config?x=9b64180aaf312512 dashboard link: https://syzkaller.appspot.com/bug?extid=837b8c9032c053262db8 compiler: Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/6b9ac6b68fe1/disk-6cd06ab1.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/694d14350cd9/vmlinux-6cd06ab1.xz kernel image: https://storage.googleapis.com/syzbot-assets/0344e65f0f1c/bzImage-6cd06ab1.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+837b8c9032c053262db8@xxxxxxxxxxxxxxxxxxxxxxxxx general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] CPU: 1 PID: 12722 Comm: kworker/1:25 Not tainted 6.4.0-syzkaller-11479-g6cd06ab12d1a #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023 Workqueue: pm pm_runtime_work RIP: 0010:serial8250_tx_chars+0x299/0x8b0 drivers/tty/serial/8250/8250_port.c:1813 Code: 5d 36 26 fd 48 8b 2b 48 8b 44 24 20 42 0f b6 04 38 84 c0 0f 85 8f 02 00 00 48 8b 04 24 48 63 00 48 01 c5 48 89 e8 48 c1 e8 03 <42> 0f b6 04 38 84 c0 0f 85 91 02 00 00 0f b6 6d 00 48 8b 44 24 60 RSP: 0018:ffffc9000abdf8d0 EFLAGS: 00010046 RAX: 0000000000000000 RBX: ffff88801f1c0fd0 RCX: 1ffffffff246560f RDX: 1ffffffff2465659 RSI: 0000000000000000 RDI: ffffffff9232b2d0 RBP: 0000000000000000 R08: ffffffff84be7c90 R09: fffff5200157bf14 R10: dffffc0000000000 R11: fffff5200157bf14 R12: 0000000000000010 R13: ffffffff9232b120 R14: ffffffff9232b020 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020404030 CR3: 000000000d130000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> __start_tx+0x312/0x450 drivers/tty/serial/8250/8250_port.c:1547 serial_port_runtime_resume+0x1ec/0x2a0 drivers/tty/serial/serial_port.c:40 __rpm_callback+0x2b9/0x7a0 drivers/base/power/runtime.c:392 rpm_callback drivers/base/power/runtime.c:446 [inline] rpm_resume+0x10b1/0x1af0 drivers/base/power/runtime.c:912 pm_runtime_work+0x147/0x210 drivers/base/power/runtime.c:977 process_one_work+0x92c/0x12c0 kernel/workqueue.c:2597 worker_thread+0xa63/0x1210 kernel/workqueue.c:2748 kthread+0x2b8/0x350 kernel/kthread.c:389 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 </TASK> Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:serial8250_tx_chars+0x299/0x8b0 drivers/tty/serial/8250/8250_port.c:1813 Code: 5d 36 26 fd 48 8b 2b 48 8b 44 24 20 42 0f b6 04 38 84 c0 0f 85 8f 02 00 00 48 8b 04 24 48 63 00 48 01 c5 48 89 e8 48 c1 e8 03 <42> 0f b6 04 38 84 c0 0f 85 91 02 00 00 0f b6 6d 00 48 8b 44 24 60 RSP: 0018:ffffc9000abdf8d0 EFLAGS: 00010046 RAX: 0000000000000000 RBX: ffff88801f1c0fd0 RCX: 1ffffffff246560f RDX: 1ffffffff2465659 RSI: 0000000000000000 RDI: ffffffff9232b2d0 RBP: 0000000000000000 R08: ffffffff84be7c90 R09: fffff5200157bf14 R10: dffffc0000000000 R11: fffff5200157bf14 R12: 0000000000000010 R13: ffffffff9232b120 R14: ffffffff9232b020 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020404030 CR3: 000000000d130000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: 5d pop %rbp 1: 36 26 fd ss es std 4: 48 8b 2b mov (%rbx),%rbp 7: 48 8b 44 24 20 mov 0x20(%rsp),%rax c: 42 0f b6 04 38 movzbl (%rax,%r15,1),%eax 11: 84 c0 test %al,%al 13: 0f 85 8f 02 00 00 jne 0x2a8 19: 48 8b 04 24 mov (%rsp),%rax 1d: 48 63 00 movslq (%rax),%rax 20: 48 01 c5 add %rax,%rbp 23: 48 89 e8 mov %rbp,%rax 26: 48 c1 e8 03 shr $0x3,%rax * 2a: 42 0f b6 04 38 movzbl (%rax,%r15,1),%eax <-- trapping instruction 2f: 84 c0 test %al,%al 31: 0f 85 91 02 00 00 jne 0x2c8 37: 0f b6 6d 00 movzbl 0x0(%rbp),%ebp 3b: 48 8b 44 24 60 mov 0x60(%rsp),%rax --- 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 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
