On 04/12/19 05:15, syzbot wrote: > Hello, > > syzbot found the following crash on: > > HEAD commit: 596cf45c Merge branch 'akpm' (patches from Andrew) > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=103acb7ae00000 > kernel config: https://syzkaller.appspot.com/x/.config?x=8eb54eee6e6ca4a7 > dashboard link: > https://syzkaller.appspot.com/bug?extid=e3f4897236c4eeb8af4f > compiler: gcc (GCC) 9.0.0 20181231 (experimental) > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15b87c82e00000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11250f36e00000 > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+e3f4897236c4eeb8af4f@xxxxxxxxxxxxxxxxxxxxxxxxx > > ================================================================== > BUG: KASAN: vmalloc-out-of-bounds in __do_cpuid_func_emulated > arch/x86/kvm/cpuid.c:323 [inline] > BUG: KASAN: vmalloc-out-of-bounds in do_cpuid_func > arch/x86/kvm/cpuid.c:814 [inline] > BUG: KASAN: vmalloc-out-of-bounds in do_cpuid_func > arch/x86/kvm/cpuid.c:810 [inline] > BUG: KASAN: vmalloc-out-of-bounds in kvm_dev_ioctl_get_cpuid+0xad7/0xb0b > arch/x86/kvm/cpuid.c:891 > Write of size 4 at addr ffffc90000d36050 by task syz-executor490/9767 > > CPU: 1 PID: 9767 Comm: syz-executor490 Not tainted 5.4.0-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > Google 01/01/2011 > Call Trace: > __dump_stack lib/dump_stack.c:77 [inline] > dump_stack+0x197/0x210 lib/dump_stack.c:118 > print_address_description.constprop.0.cold+0x5/0x30b mm/kasan/report.c:374 > __kasan_report.cold+0x1b/0x41 mm/kasan/report.c:506 > kasan_report+0x12/0x20 mm/kasan/common.c:638 > __asan_report_store4_noabort+0x17/0x20 mm/kasan/generic_report.c:139 > __do_cpuid_func_emulated arch/x86/kvm/cpuid.c:323 [inline] > do_cpuid_func arch/x86/kvm/cpuid.c:814 [inline] > do_cpuid_func arch/x86/kvm/cpuid.c:810 [inline] > kvm_dev_ioctl_get_cpuid+0xad7/0xb0b arch/x86/kvm/cpuid.c:891 > kvm_arch_dev_ioctl+0x300/0x4b0 arch/x86/kvm/x86.c:3387 > kvm_dev_ioctl+0x127/0x17d0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3593 > vfs_ioctl fs/ioctl.c:47 [inline] > file_ioctl fs/ioctl.c:539 [inline] > do_vfs_ioctl+0xdb6/0x13e0 fs/ioctl.c:726 > ksys_ioctl+0xab/0xd0 fs/ioctl.c:743 > __do_sys_ioctl fs/ioctl.c:750 [inline] > __se_sys_ioctl fs/ioctl.c:748 [inline] > __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:748 > do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > RIP: 0033:0x440159 > Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 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 0f 83 fb 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00 > RSP: 002b:00007ffd106332c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 > RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440159 > RDX: 0000000020000080 RSI: 00000000c008ae09 RDI: 0000000000000003 > RBP: 00000000006ca018 R08: 0000000000000000 R09: 00000000004002c8 > R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004019e0 > R13: 0000000000401a70 R14: 0000000000000000 R15: 0000000000000000 > > > Memory state around the buggy address: > ffffc90000d35f00: f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 > ffffc90000d35f80: f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 >> ffffc90000d36000: 00 00 00 00 00 00 00 00 00 00 f9 f9 f9 f9 f9 f9 > ^ > ffffc90000d36080: f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 > ffffc90000d36100: f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 > ================================================================== > > > --- > This bug 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 bug report. See: > https://goo.gl/tpsmEJ#status for how to communicate with syzbot. > syzbot can test patches for this bug, for details see: > https://goo.gl/tpsmEJ#testing-patches > Ouch, this is bad. Sending a patch now. Paolo
