From mboxrd@z Thu Jan 1 00:00:00 1970 From: syzbot Subject: KASAN: out-of-bounds Read in bpf_test_finish Date: Mon, 09 Jul 2018 05:44:02 -0700 Message-ID: <0000000000003f78f30570905ed6@google.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8"; format=flowed; delsp=yes To: ast@kernel.org, daniel@iogearbox.net, davem@davemloft.net, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, syzkaller-bugs@googlegroups.com Return-path: Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Hello, syzbot found the following crash on: HEAD commit: d90c936fb318 Merge branch 'bpf-nfp-mul-div-support' git tree: bpf-next console output: https://syzkaller.appspot.com/x/log.txt?x=16b88a78400000 kernel config: https://syzkaller.appspot.com/x/.config?x=a501a01deaf0fe9 dashboard link: https://syzkaller.appspot.com/bug?extid=54f39d6ab58f39720a55 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+54f39d6ab58f39720a55@syzkaller.appspotmail.com ================================================================== BUG: KASAN: out-of-bounds in _copy_to_user+0xe9/0x110 lib/usercopy.c:27 Read of size 924 at addr ffff880192bffff2 by task syz-executor1/6688 CPU: 1 PID: 6688 Comm: syz-executor1 Not tainted 4.18.0-rc3+ #48 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 check_memory_region_inline mm/kasan/kasan.c:260 [inline] check_memory_region+0x13e/0x1b0 mm/kasan/kasan.c:267 kasan_check_read+0x11/0x20 mm/kasan/kasan.c:272 _copy_to_user+0xe9/0x110 lib/usercopy.c:27 copy_to_user include/linux/uaccess.h:155 [inline] bpf_test_finish.isra.7+0xee/0x1f0 net/bpf/test_run.c:59 bpf_prog_test_run_skb+0x7d7/0xa30 net/bpf/test_run.c:144 bpf_prog_test_run+0x130/0x1a0 kernel/bpf/syscall.c:1686 __do_sys_bpf kernel/bpf/syscall.c:2323 [inline] __se_sys_bpf kernel/bpf/syscall.c:2267 [inline] __x64_sys_bpf+0x3d8/0x510 kernel/bpf/syscall.c:2267 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x455e29 Code: 1d ba fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 eb b9 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f95802f1c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f95802f26d4 RCX: 0000000000455e29 RDX: 0000000000000028 RSI: 0000000020000380 RDI: 000000000000000a RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004bbaee R14: 00000000004c8d20 R15: 0000000000000000 The buggy address belongs to the page: page:ffffea00064a8000 count:1 mapcount:1 mapping:ffff8801ceeda041 index:0x20200 compound_mapcount: 1 flags: 0x2fffc0000048068(uptodate|lru|active|head|swapbacked) raw: 02fffc0000048068 ffffea0006d642c8 ffffea0006e14288 ffff8801ceeda041 raw: 0000000000020200 0000000000000000 00000001ffffffff ffff8801d285e900 page dumped because: kasan: bad access detected page->mem_cgroup:ffff8801d285e900 Memory state around the buggy address: ffff880192c00280: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff880192c00300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > ffff880192c00380: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ^ ffff880192c00400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff880192c00480: 00 00 00 00 00 00 00 00 00 00 00 00 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@googlegroups.com. syzbot will keep track of this bug report. See: https://goo.gl/tpsmEJ#bug-status-tracking for how to communicate with syzbot.