Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754805AbeANAWS (ORCPT + 1 other); Sat, 13 Jan 2018 19:22:18 -0500 Received: from www62.your-server.de ([213.133.104.62]:43414 "EHLO www62.your-server.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754614AbeANAWQ (ORCPT ); Sat, 13 Jan 2018 19:22:16 -0500 Subject: Re: BUG: unable to handle kernel paging request in check_memory_region To: Dmitry Vyukov , syzbot Cc: Alexei Starovoitov , LKML , netdev , syzkaller-bugs@googlegroups.com References: <001a113feecc4fa53a05629c32a5@google.com> From: Daniel Borkmann Message-ID: <8bf5e24e-1bce-81dc-4e92-80ce20c5d152@iogearbox.net> Date: Sun, 14 Jan 2018 01:22:13 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.3.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Authenticated-Sender: daniel@iogearbox.net Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: On 01/13/2018 08:29 AM, Dmitry Vyukov wrote: > On Fri, Jan 12, 2018 at 11:58 PM, syzbot > wrote: >> Hello, >> >> syzkaller hit the following crash on >> c92a9a461dff6140c539c61e457aa97df29517d6 >> git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/master >> compiler: gcc (GCC) 7.1.1 20170620 >> .config is attached >> Raw console output is attached. >> C reproducer is attached >> syzkaller reproducer is attached. See https://goo.gl/kgGztJ >> for information about syzkaller reproducers >> >> >> IMPORTANT: if you fix the bug, please add the following tag to the commit: >> Reported-by: syzbot+32b24f3e7c9000c48490@syzkaller.appspotmail.com >> It will help syzbot understand when the bug is fixed. See footer for >> details. >> If you forward the report, please keep this part and the footer. > > > Daniel, is it the same bug that was fixed by "bpf, array: fix overflow > in max_entries and undefined behavior in index_mask"? And also here, fixed by: https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf.git/commit/?id=bbeb6e4323dad9b5e0ee9f60c223dd532e2403b1 >> audit: type=1400 audit(1515790631.378:9): avc: denied { sys_chroot } for >> pid=3510 comm="syzkaller602893" capability=18 >> scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 >> tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns >> permissive=1 >> BUG: unable to handle kernel paging request at ffffed004e875e33 >> IP: bytes_is_nonzero mm/kasan/kasan.c:166 [inline] >> IP: memory_is_nonzero mm/kasan/kasan.c:184 [inline] >> IP: memory_is_poisoned_n mm/kasan/kasan.c:210 [inline] >> IP: memory_is_poisoned mm/kasan/kasan.c:241 [inline] >> IP: check_memory_region_inline mm/kasan/kasan.c:257 [inline] >> IP: check_memory_region+0x61/0x190 mm/kasan/kasan.c:267 >> PGD 21ffee067 P4D 21ffee067 PUD 21ffec067 PMD 0 >> Oops: 0000 [#1] SMP KASAN >> Dumping ftrace buffer: >> (ftrace buffer empty) >> Modules linked in: >> CPU: 0 PID: 3510 Comm: syzkaller602893 Not tainted 4.15.0-rc7+ #259 >> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS >> Google 01/01/2011 >> RIP: 0010:bytes_is_nonzero mm/kasan/kasan.c:166 [inline] >> RIP: 0010:memory_is_nonzero mm/kasan/kasan.c:184 [inline] >> RIP: 0010:memory_is_poisoned_n mm/kasan/kasan.c:210 [inline] >> RIP: 0010:memory_is_poisoned mm/kasan/kasan.c:241 [inline] >> RIP: 0010:check_memory_region_inline mm/kasan/kasan.c:257 [inline] >> RIP: 0010:check_memory_region+0x61/0x190 mm/kasan/kasan.c:267 >> RSP: 0018:ffff8801bfa77770 EFLAGS: 00010202 >> RAX: ffffed004e875e33 RBX: ffff8802743af19b RCX: ffffffff817deb1c >> RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff8802743af198 >> RBP: ffff8801bfa77780 R08: 1ffff1004e875e33 R09: ffffed004e875e33 >> R10: 0000000000000001 R11: ffffed004e875e33 R12: ffffed004e875e34 >> R13: ffff8802743af198 R14: ffff8801bfc9f000 R15: ffff8801c135a680 >> FS: 0000000001a1d880(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 >> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 >> CR2: ffffed004e875e33 CR3: 00000001bfe22003 CR4: 00000000001606f0 >> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 >> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 >> Call Trace: >> memcpy+0x23/0x50 mm/kasan/kasan.c:302 >> memcpy include/linux/string.h:344 [inline] >> map_lookup_elem+0x4dc/0xbd0 kernel/bpf/syscall.c:584 >> SYSC_bpf kernel/bpf/syscall.c:1711 [inline] >> SyS_bpf+0x922/0x4400 kernel/bpf/syscall.c:1685 >> entry_SYSCALL_64_fastpath+0x23/0x9a >> RIP: 0033:0x440ac9 >> RSP: 002b:00000000007dff68 EFLAGS: 00000203 ORIG_RAX: 0000000000000141 >> RAX: ffffffffffffffda RBX: ffffffffffffffff RCX: 0000000000440ac9 >> RDX: 0000000000000018 RSI: 0000000020eed000 RDI: 0000000000000001 >> RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 >> R10: 0000000000000000 R11: 0000000000000203 R12: 00000000004022a0 >> R13: 0000000000402330 R14: 0000000000000000 R15: 0000000000000000 >> Code: 89 f8 49 c1 e8 03 49 89 db 49 c1 eb 03 4d 01 cb 4d 01 c1 4d 8d 63 01 >> 4c 89 c8 4d 89 e2 4d 29 ca 49 83 fa 10 7f 3d 4d 85 d2 74 33 <41> 80 39 00 75 >> 21 48 b8 01 00 00 00 00 fc ff df 4d 01 d1 49 01 >> RIP: bytes_is_nonzero mm/kasan/kasan.c:166 [inline] RSP: ffff8801bfa77770 >> RIP: memory_is_nonzero mm/kasan/kasan.c:184 [inline] RSP: ffff8801bfa77770 >> RIP: memory_is_poisoned_n mm/kasan/kasan.c:210 [inline] RSP: >> ffff8801bfa77770 >> RIP: memory_is_poisoned mm/kasan/kasan.c:241 [inline] RSP: ffff8801bfa77770 >> RIP: check_memory_region_inline mm/kasan/kasan.c:257 [inline] RSP: >> ffff8801bfa77770 >> RIP: check_memory_region+0x61/0x190 mm/kasan/kasan.c:267 RSP: >> ffff8801bfa77770 >> CR2: ffffed004e875e33 >> ---[ end trace 769bd3705f3abe78 ]--- >> Kernel panic - not syncing: Fatal exception >> Dumping ftrace buffer: >> (ftrace buffer empty) >> Kernel Offset: disabled >> Rebooting in 86400 seconds.. >> >> >> --- >> This bug is generated by a dumb bot. It may contain errors. >> See https://goo.gl/tpsmEJ for details. >> Direct all questions to syzkaller@googlegroups.com. >> >> syzbot will keep track of this bug report. >> If you forgot to add the Reported-by tag, once the fix for this bug is >> merged >> into any tree, please reply to this email with: >> #syz fix: exact-commit-title >> If you want to test a patch for this bug, please reply with: >> #syz test: git://repo/address.git branch >> and provide the patch inline or as an attachment. >> To mark this as a duplicate of another syzbot report, please reply with: >> #syz dup: exact-subject-of-another-report >> If it's a one-off invalid bug report, please reply with: >> #syz invalid >> Note: if the crash happens again, it will cause creation of a new bug >> report. >> Note: all commands must start from beginning of the line in the email body. >> >> -- >> 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@googlegroups.com. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/syzkaller-bugs/001a113feecc4fa53a05629c32a5%40google.com. >> For more options, visit https://groups.google.com/d/optout.