#syz dup: KASAN: use-after-free Read in do_general_protection On Sun, May 13, 2018 at 4:21 PM, syzbot <syzbot+d8f8a4d784b336549b5b@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > Hello, > > syzbot found the following crash on: > > HEAD commit: 036db8bd9637 Merge branch 'for-4.17-fixes' of git://git.ke.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=11228e07800000 > kernel config: https://syzkaller.appspot.com/x/.config?x=31f4b3733894ef79 > dashboard link: https://syzkaller.appspot.com/bug?extid=d8f8a4d784b336549b5b > 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+d8f8a4d784b336549b5b@xxxxxxxxxxxxxxxxxxxxxxxxx > > ================================================================== > BUG: KASAN: slab-out-of-bounds in msr_write_intercepted > arch/x86/kvm/vmx.c:2126 [inline] > BUG: KASAN: slab-out-of-bounds in vmx_vcpu_run+0x2379/0x25f0 > arch/x86/kvm/vmx.c:9869 > Read of size 8 at addr ffff8801d3efc840 by task syz-executor1/11848 > > CPU: 1 PID: 11848 Comm: syz-executor1 Not tainted 4.17.0-rc4+ #39 > 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+0x1b9/0x294 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 > msr_write_intercepted arch/x86/kvm/vmx.c:2126 [inline] > vmx_vcpu_run+0x2379/0x25f0 arch/x86/kvm/vmx.c:9869 > > Allocated by task 11848: > save_stack+0x43/0xd0 mm/kasan/kasan.c:448 > set_track mm/kasan/kasan.c:460 [inline] > kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:553 > kmem_cache_alloc_trace+0x152/0x780 mm/slab.c:3620 > kmalloc include/linux/slab.h:512 [inline] > kzalloc include/linux/slab.h:701 [inline] > tcp_sendmsg_fastopen net/ipv4/tcp.c:1145 [inline] > tcp_sendmsg_locked+0x2ff7/0x3ee0 net/ipv4/tcp.c:1209 > tcp_sendmsg+0x2f/0x50 net/ipv4/tcp.c:1447 > inet_sendmsg+0x19f/0x690 net/ipv4/af_inet.c:798 > sock_sendmsg_nosec net/socket.c:629 [inline] > sock_sendmsg+0xd5/0x120 net/socket.c:639 > __sys_sendto+0x3d7/0x670 net/socket.c:1789 > __do_sys_sendto net/socket.c:1801 [inline] > __se_sys_sendto net/socket.c:1797 [inline] > __x64_sys_sendto+0xe1/0x1a0 net/socket.c:1797 > do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > > Freed by task 2388: > save_stack+0x43/0xd0 mm/kasan/kasan.c:448 > set_track mm/kasan/kasan.c:460 [inline] > __kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:521 > kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 > __cache_free mm/slab.c:3498 [inline] > kfree+0xd9/0x260 mm/slab.c:3813 > inotify_free_event+0x15/0x20 fs/notify/inotify/inotify_fsnotify.c:182 > fsnotify_destroy_event.part.1+0x1a8/0x270 fs/notify/notification.c:87 > fsnotify_destroy_event+0x69/0x80 fs/notify/notification.c:74 > inotify_read+0x5a8/0x9b0 fs/notify/inotify/inotify_user.c:246 > __vfs_read+0x10f/0xa50 fs/read_write.c:416 > vfs_read+0x17f/0x3d0 fs/read_write.c:452 > ksys_read+0xf9/0x250 fs/read_write.c:578 > __do_sys_read fs/read_write.c:588 [inline] > __se_sys_read fs/read_write.c:586 [inline] > __x64_sys_read+0x73/0xb0 fs/read_write.c:586 > do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > > The buggy address belongs to the object at ffff8801d3efc800 > which belongs to the cache kmalloc-64 of size 64 > The buggy address is located 0 bytes to the right of > 64-byte region [ffff8801d3efc800, ffff8801d3efc840) > The buggy address belongs to the page: > page:ffffea00074fbf00 count:1 mapcount:0 mapping:ffff8801d3efc000 index:0x0 > flags: 0x2fffc0000000100(slab) > raw: 02fffc0000000100 ffff8801d3efc000 0000000000000000 0000000100000020 > raw: ffffea00076687a0 ffffea000766e660 ffff8801da800340 0000000000000000 > page dumped because: kasan: bad access detected > > Memory state around the buggy address: > ffff8801d3efc700: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc > ffff8801d3efc780: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc >> >> ffff8801d3efc800: 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc > > ^ > ffff8801d3efc880: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc > ffff8801d3efc900: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc > ================================================================== > > > --- > 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. > > -- > You received this message because you are subscribed to the Google Groups > "syzkaller-bugs" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to syzkaller-bugs+unsubscribe@xxxxxxxxxxxxxxxx. > To view this discussion on the web visit > https://groups.google.com/d/msgid/syzkaller-bugs/0000000000002d64fe056c1714a3%40google.com. > For more options, visit https://groups.google.com/d/optout.
