On Wed, Jun 20, 2018 at 8:04 AM, syzbot <syzbot+3ae3575e398ca1d88e5d@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > Hello, > > syzbot found the following crash on: > > HEAD commit: ba4dbdedd3ed Merge tag 'jfs-4.18' of git://github.com/klei.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=17fe8bd8400000 > kernel config: https://syzkaller.appspot.com/x/.config?x=f390986c4f7cd566 > dashboard link: https://syzkaller.appspot.com/bug?extid=3ae3575e398ca1d88e5d > compiler: gcc (GCC) 8.0.1 20180413 (experimental) > > Unfortunately, I don't have any reproducer for this crash yet. > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+3ae3575e398ca1d88e5d@xxxxxxxxxxxxxxxxxxxxxxxxx Not sure what's with the unwind here, but it looks like the culprit is msr_write_intercepted. So +KVM maintainers and: #syz dup: KASAN: use-after-free Read in do_general_protection > kvm: pic: single mode not supported > ================================================================== > BUG: KASAN: stack-out-of-bounds in __read_once_size > include/linux/compiler.h:188 [inline] > BUG: KASAN: stack-out-of-bounds in unwind_next_frame.part.7+0x801/0x9e0 > arch/x86/kernel/unwind_frame.c:326 > Read of size 8 at addr ffff88017c386c78 by task syz-executor0/22016 > > CPU: 1 PID: 22016 Comm: syz-executor0 Not tainted 4.18.0-rc1+ #109 > 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+0x1c9/0x2b4 lib/dump_stack.c:113 > print_address_description+0x6c/0x20b mm/kasan/report.c:256 > kasan_report_error mm/kasan/report.c:354 [inline] > kasan_report.cold.7+0x242/0x2fe mm/kasan/report.c:412 > __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433 > __read_once_size include/linux/compiler.h:188 [inline] > unwind_next_frame.part.7+0x801/0x9e0 arch/x86/kernel/unwind_frame.c:326 > unwind_next_frame+0x3e/0x50 arch/x86/kernel/unwind_frame.c:287 > __save_stack_trace+0x7d/0xf0 arch/x86/kernel/stacktrace.c:44 > save_stack_trace+0x1a/0x20 arch/x86/kernel/stacktrace.c:60 > save_trace+0xe0/0x290 kernel/locking/lockdep.c:404 > check_prev_add kernel/locking/lockdep.c:1915 [inline] > check_prevs_add kernel/locking/lockdep.c:1980 [inline] > validate_chain kernel/locking/lockdep.c:2421 [inline] > __lock_acquire+0x39a8/0x5020 kernel/locking/lockdep.c:3435 > lock_acquire+0x1e4/0x540 kernel/locking/lockdep.c:3924 > __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] > _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:144 > vprintk_emit+0x191/0xdf0 kernel/printk/printk.c:1848 > vprintk_default+0x28/0x30 kernel/printk/printk.c:1948 > vprintk_func+0x7a/0xe7 kernel/printk/printk_safe.c:382 > printk+0xa7/0xcf kernel/printk/printk.c:1981 > kasan_die_handler.cold.22+0x11/0x30 arch/x86/mm/kasan_init_64.c:251 > notifier_call_chain+0x180/0x390 kernel/notifier.c:93 > __atomic_notifier_call_chain kernel/notifier.c:183 [inline] > atomic_notifier_call_chain+0x98/0x190 kernel/notifier.c:193 > notify_die+0x1be/0x2e0 kernel/notifier.c:549 > do_general_protection+0x248/0x2f0 arch/x86/kernel/traps.c:559 > general_protection+0x1e/0x30 arch/x86/entry/entry_64.S:1159 > RIP: 0010:msr_write_intercepted arch/x86/kvm/vmx.c:2327 [inline] > RIP: 0010:vmx_vcpu_run+0x131a/0x2600 arch/x86/kvm/vmx.c:10149 > Code: 00 00 10 89 de e8 36 65 5c 00 85 db 0f 84 91 00 00 00 e8 19 64 5c 00 > 48 8b 54 24 08 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <80> 3c 02 00 0f 85 > 8c 10 00 00 48 8b 04 24 48 8b 98 40 57 00 00 48 > RSP: 0018:ffff88017c387370 EFLAGS: 00010002 > RAX: dffffc0000000000 RBX: 0000000010000000 RCX: ffffffff811f467a > RDX: 000000000000045b RSI: ffffffff811f4687 RDI: 0000000000000005 > RBP: ffff88017c3873a8 R08: ffff8801b0e4a080 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 > R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 > > The buggy address belongs to the page: > page:ffffea0005f0e180 count:0 mapcount:0 mapping:0000000000000000 > index:0xffff88017c386940 > flags: 0x2fffc0000000000() > raw: 02fffc0000000000 0000000000000000 dead000000000200 0000000000000000 > raw: ffff88017c386940 0000000000000000 00000000ffffffff 0000000000000000 > page dumped because: kasan: bad access detected > > Memory state around the buggy address: > ffff88017c386b00: f2 f2 f8 f2 f2 f2 f2 f2 f2 f2 00 f2 f2 f2 f2 f2 > ffff88017c386b80: f2 f2 f8 f2 f2 f2 f2 f2 f2 f2 00 f2 f2 f2 f2 f2 >> >> ffff88017c386c00: f2 f2 f8 f2 f2 f2 00 00 00 00 00 00 00 f2 f2 f2 > > ^ > ffff88017c386c80: 00 f2 f2 f2 f2 f2 f2 f2 00 f2 f1 f1 f1 f1 00 f2 > ffff88017c386d00: f2 f2 f2 f2 f2 f2 f8 f2 f2 f2 f2 f2 00 00 00 00 > ================================================================== > > > --- > 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#bug-status-tracking for how to communicate with > syzbot.
