On Thu, Jan 11, 2024 at 8:25 AM syzbot <syzbot+705209281e36404998f6@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > > Hello, > > syzbot found the following issue on: > > HEAD commit: e2425464bc87 Add linux-next specific files for 20240105 > git tree: linux-next > console+strace: https://syzkaller.appspot.com/x/log.txt?x=14941cdee80000 > kernel config: https://syzkaller.appspot.com/x/.config?x=4056b9349f3da8c9 > dashboard link: https://syzkaller.appspot.com/bug?extid=705209281e36404998f6 > compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=125d0a09e80000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15bc7331e80000 > > Downloadable assets: > disk image: https://storage.googleapis.com/syzbot-assets/2f738185e2cf/disk-e2425464.raw.xz > vmlinux: https://storage.googleapis.com/syzbot-assets/b248fcf4ea46/vmlinux-e2425464.xz > kernel image: https://storage.googleapis.com/syzbot-assets/a9945c8223f4/bzImage-e2425464.xz > > The issue was bisected to: > > commit adef440691bab824e39c1b17382322d195e1fab0 > Author: Andrea Arcangeli <aarcange@xxxxxxxxxx> > Date: Wed Dec 6 10:36:56 2023 +0000 > > userfaultfd: UFFDIO_MOVE uABI > > bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=11cb6ea9e80000 > final oops: https://syzkaller.appspot.com/x/report.txt?x=13cb6ea9e80000 > console output: https://syzkaller.appspot.com/x/log.txt?x=15cb6ea9e80000 > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+705209281e36404998f6@xxxxxxxxxxxxxxxxxxxxxxxxx > Fixes: adef440691ba ("userfaultfd: UFFDIO_MOVE uABI") > > do_one_initcall+0x128/0x680 init/main.c:1237 > do_initcall_level init/main.c:1299 [inline] > do_initcalls init/main.c:1315 [inline] > do_basic_setup init/main.c:1334 [inline] > kernel_init_freeable+0x692/0xc30 init/main.c:1552 > kernel_init+0x1c/0x2a0 init/main.c:1442 > ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 > ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242 > ------------[ cut here ]------------ > kernel BUG at include/linux/page-flags.h:1035! > invalid opcode: 0000 [#1] PREEMPT SMP KASAN > CPU: 0 PID: 5068 Comm: syz-executor191 Not tainted 6.7.0-rc8-next-20240105-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023 > RIP: 0010:PageAnonExclusive include/linux/page-flags.h:1035 [inline] >From a quick look, I think the new ioctl is being used against a file-backed page and that's why PageAnonExclusive() throws this error. I'll confirm if this is indeed the case and will add checks for that case. Thanks! > RIP: 0010:move_pages+0x1697/0x3d40 mm/userfaultfd.c:1402 > Code: 00 00 48 c1 e8 0c 48 21 d0 48 c1 e0 06 48 01 c3 e9 b6 f7 ff ff e8 79 c6 9c ff 48 c7 c6 e0 7e dc 8a 48 89 df e8 0a 20 dc ff 90 <0f> 0b e8 62 c6 9c ff 48 89 da b8 ff ff 37 00 48 c1 ea 03 48 c1 e0 > RSP: 0018:ffffc90003aefa98 EFLAGS: 00010293 > RAX: 0000000000000000 RBX: ffffea0001e40000 RCX: ffffffff81687599 > RDX: ffff88802a155940 RSI: ffffffff81eb5d46 RDI: 0000000000000000 > RBP: ffff88802abab810 R08: 0000000000000000 R09: fffffbfff1e75fda > R10: ffffffff8f3afed7 R11: 0000000000000001 R12: 0000000000000000 > R13: 0000000000000000 R14: 0000000020518000 R15: 0000000000000000 > FS: 00005555562cf380(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 00000000204f8000 CR3: 000000006a725000 CR4: 00000000003506f0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > <TASK> > userfaultfd_move fs/userfaultfd.c:2047 [inline] > userfaultfd_ioctl+0x683/0x6420 fs/userfaultfd.c:2169 > vfs_ioctl fs/ioctl.c:51 [inline] > __do_sys_ioctl fs/ioctl.c:871 [inline] > __se_sys_ioctl fs/ioctl.c:857 [inline] > __x64_sys_ioctl+0x18f/0x210 fs/ioctl.c:857 > do_syscall_x64 arch/x86/entry/common.c:52 [inline] > do_syscall_64+0xd0/0x250 arch/x86/entry/common.c:83 > entry_SYSCALL_64_after_hwframe+0x62/0x6a > RIP: 0033:0x7f4bada9b3e9 > Code: 48 83 c4 28 c3 e8 37 17 00 00 0f 1f 80 00 00 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 b8 ff ff ff f7 d8 64 89 01 48 > RSP: 002b:00007fff2c1d6998 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 > RAX: ffffffffffffffda RBX: 00007fff2c1d6b68 RCX: 00007f4bada9b3e9 > RDX: 00000000200000c0 RSI: 00000000c028aa05 RDI: 0000000000000003 > RBP: 00007f4badb0e610 R08: 00007fff2c1d6b68 R09: 00007fff2c1d6b68 > R10: 00007fff2c1d6b68 R11: 0000000000000246 R12: 0000000000000001 > R13: 00007fff2c1d6b58 R14: 0000000000000001 R15: 0000000000000001 > </TASK> > Modules linked in: > ---[ end trace 0000000000000000 ]--- > RIP: 0010:PageAnonExclusive include/linux/page-flags.h:1035 [inline] > RIP: 0010:move_pages+0x1697/0x3d40 mm/userfaultfd.c:1402 > Code: 00 00 48 c1 e8 0c 48 21 d0 48 c1 e0 06 48 01 c3 e9 b6 f7 ff ff e8 79 c6 9c ff 48 c7 c6 e0 7e dc 8a 48 89 df e8 0a 20 dc ff 90 <0f> 0b e8 62 c6 9c ff 48 89 da b8 ff ff 37 00 48 c1 ea 03 48 c1 e0 > RSP: 0018:ffffc90003aefa98 EFLAGS: 00010293 > RAX: 0000000000000000 RBX: ffffea0001e40000 RCX: ffffffff81687599 > RDX: ffff88802a155940 RSI: ffffffff81eb5d46 RDI: 0000000000000000 > RBP: ffff88802abab810 R08: 0000000000000000 R09: fffffbfff1e75fda > R10: ffffffff8f3afed7 R11: 0000000000000001 R12: 0000000000000000 > R13: 0000000000000000 R14: 0000000020518000 R15: 0000000000000000 > FS: 00005555562cf380(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 00000000204f8000 CR3: 000000006a725000 CR4: 00000000003506f0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > > > --- > 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. > For information about bisection process see: https://goo.gl/tpsmEJ#bisection > > If the report is already addressed, 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 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
