Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754505AbeANAV7 (ORCPT + 1 other); Sat, 13 Jan 2018 19:21:59 -0500 Received: from www62.your-server.de ([213.133.104.62]:43367 "EHLO www62.your-server.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751168AbeANAV5 (ORCPT ); Sat, 13 Jan 2018 19:21:57 -0500 Subject: Re: general protection fault in __bpf_map_put To: Dmitry Vyukov , syzbot Cc: Alexei Starovoitov , LKML , netdev , syzkaller-bugs@googlegroups.com References: <94eb2c06de30df3d1605626b941b@google.com> From: Daniel Borkmann Message-ID: Date: Sun, 14 Jan 2018 01:21:54 +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 08:16 AM, Dmitry Vyukov wrote: > On Wed, Jan 10, 2018 at 1:58 PM, syzbot > wrote: >> Hello, >> >> syzkaller hit the following crash on >> b4464bcab38d3f7fe995a7cb960eeac6889bec08 >> git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.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+d2f5524fb46fd3b312ee@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"? Yes, fixed by: https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf.git/commit/?id=bbeb6e4323dad9b5e0ee9f60c223dd532e2403b1 >> audit: type=1400 audit(1515571663.627:11): avc: denied { map_read >> map_write } for pid=3537 comm="syzkaller597104" >> scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 >> tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=bpf >> permissive=1 >> kasan: CONFIG_KASAN_INLINE enabled >> kasan: GPF could be caused by NULL-ptr deref or user memory access >> general protection fault: 0000 [#1] SMP KASAN >> Dumping ftrace buffer: >> (ftrace buffer empty) >> Modules linked in: >> CPU: 1 PID: 23 Comm: kworker/1:1 Not tainted 4.15.0-rc7-next-20180110+ #93 >> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS >> Google 01/01/2011 >> Workqueue: events bpf_map_free_deferred >> RIP: 0010:__bpf_map_put+0x64/0x2e0 kernel/bpf/syscall.c:233 >> RSP: 0018:ffff8801d98b7458 EFLAGS: 00010293 >> RAX: ffff8801d98ac600 RBX: ad6001bc00000dd1 RCX: ffffffff817e4454 >> RDX: 0000000000000000 RSI: 0000000000000001 RDI: ad6001bc00000dd1 >> RBP: ffff8801d98b74e8 R08: 1ffff1003b316e6a R09: 0000000000000000 >> R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff1003b316e8c >> R13: dffffc0000000000 R14: dffffc0000000000 R15: 0000000000000001 >> FS: 0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 >> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 >> CR2: 00000000204f9fe4 CR3: 0000000006822003 CR4: 00000000001606e0 >> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 >> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 >> Call Trace: >> bpf_map_put+0x1a/0x20 kernel/bpf/syscall.c:243 >> bpf_map_fd_put_ptr+0x15/0x20 kernel/bpf/map_in_map.c:96 >> fd_array_map_delete_elem kernel/bpf/arraymap.c:420 [inline] >> bpf_fd_array_map_clear kernel/bpf/arraymap.c:461 [inline] >> array_of_map_free+0x100/0x180 kernel/bpf/arraymap.c:618 >> bpf_map_free_deferred+0xb0/0xe0 kernel/bpf/syscall.c:217 >> process_one_work+0xbbf/0x1af0 kernel/workqueue.c:2112 >> worker_thread+0x223/0x1990 kernel/workqueue.c:2246 >> kthread+0x33c/0x400 kernel/kthread.c:238 >> ret_from_fork+0x4b/0x60 arch/x86/entry/entry_64.S:547 >> Code: b5 41 48 c7 45 80 1d 2c 59 86 48 c7 45 88 f0 43 7e 81 c7 00 f1 f1 f1 >> f1 c7 40 04 00 f2 f2 f2 c7 40 08 f3 f3 f3 f3 e8 9c 1e f2 ff ff 4b 48 74 >> 2f e8 91 1e f2 ff 48 b8 00 00 00 00 00 fc ff df >> RIP: __bpf_map_put+0x64/0x2e0 kernel/bpf/syscall.c:233 RSP: ffff8801d98b7458 >> ---[ end trace 61592f27aaa1e096 ]--- >> 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/94eb2c06de30df3d1605626b941b%40google.com. >> For more options, visit https://groups.google.com/d/optout.