syzbot


KASAN: vmalloc-out-of-bounds Read in kvm_put_kvm

Status: upstream: reported C repro on 2022/08/20 15:58
Reported-by: syzbot+ee478a0237db20ef61f1@syzkaller.appspotmail.com
First crash: 108d, last: 108d

Cause bisection: failed (bisect log)
Patch testing requests:
Created Duration User Patch Repo Result
2022/09/09 04:52 18m gautammenghani201@gmail.com upstream OK log
2022/08/21 10:17 17m hdanton@sina.com patch https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 7ebfc85e2cd7 OK log
2022/08/21 01:33 10m hdanton@sina.com patch https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 7ebfc85e2cd7 report log

Sample crash report:
L1TF CPU bug present and SMT on, data leak possible. See CVE-2018-3646 and https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/l1tf.html for details.
==================================================================
BUG: KASAN: vmalloc-out-of-bounds in __list_del_entry_valid+0xf2/0x110 lib/list_debug.c:59
Read of size 8 at addr ffffc900039da340 by task syz-executor260/3614

CPU: 0 PID: 3614 Comm: syz-executor260 Not tainted 5.19.0-syzkaller-13930-g7ebfc85e2cd7 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:317 [inline]
 print_report.cold+0x59/0x719 mm/kasan/report.c:433
 kasan_report+0xb1/0x1e0 mm/kasan/report.c:495
 __list_del_entry_valid+0xf2/0x110 lib/list_debug.c:59
 __list_del_entry include/linux/list.h:134 [inline]
 list_del include/linux/list.h:148 [inline]
 kvm_destroy_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:1290 [inline]
 kvm_put_kvm+0x130/0xb70 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1352
 kvm_vm_release+0x3f/0x50 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1375
 __fput+0x277/0x9d0 fs/file_table.c:320
 task_work_run+0xdd/0x1a0 kernel/task_work.c:177
 exit_task_work include/linux/task_work.h:38 [inline]
 do_exit+0xad5/0x29b0 kernel/exit.c:795
 do_group_exit+0xd2/0x2f0 kernel/exit.c:925
 __do_sys_exit_group kernel/exit.c:936 [inline]
 __se_sys_exit_group kernel/exit.c:934 [inline]
 __x64_sys_exit_group+0x3a/0x50 kernel/exit.c:934
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fd7dbdc3d39
Code: Unable to access opcode bytes at RIP 0x7fd7dbdc3d0f.
RSP: 002b:00007ffce9fd1d88 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007fd7dbe383f0 RCX: 00007fd7dbdc3d39
RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffffffffffffffc0 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fd7dbe383f0
R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000001
 </TASK>

Memory state around the buggy address:
 ffffc900039da200: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
 ffffc900039da280: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
>ffffc900039da300: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
                                           ^
 ffffc900039da380: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
 ffffc900039da400: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
==================================================================

Crashes (2):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-kasan-gce 2022/08/16 16:12 upstream 7ebfc85e2cd7 7a7cb304 .config log report syz C KASAN: vmalloc-out-of-bounds Read in kvm_put_kvm
ci-upstream-kasan-gce 2022/08/16 15:56 upstream 7ebfc85e2cd7 7a7cb304 .config log report info KASAN: vmalloc-out-of-bounds Read in kvm_put_kvm
* Struck through repros no longer work on HEAD.