From mboxrd@z Thu Jan 1 00:00:00 1970 From: Roman Gushchin Subject: Re: WARNING in cgroup_exit Date: Wed, 8 May 2019 04:19:58 +0000 Message-ID: <20190508041950.GA29396@castle> References: <000000000000a573da058858083c@google.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : references : in-reply-to : content-type : content-id : content-transfer-encoding : mime-version; s=facebook; bh=PL+cCfAiQG1R6Xx5r1Hl7gTS8cogqZ6EL7hry29zehU=; b=W7cBdHkUidgmx6lLbaJHhmKy+QsaO+D1AqbDPASomvL6lyq1tqoOOBhe1HDV6OfhQyzc ye460NxRVg4Bh+AZKsiNtiaErpaoM1EsjYVI1e++0m1AFqFN/axfmMMvKyfDWJ7EOF8O ELVr1erwxaMMxJT1R/WY2gGplm0Ro/h39r0= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.onmicrosoft.com; s=selector1-fb-com; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=PL+cCfAiQG1R6Xx5r1Hl7gTS8cogqZ6EL7hry29zehU=; b=BqdEm1/r762Z6yHeYGy196B/G7KmjmNjl7DHda2ktwUFRQu/rymHqqDNLOWD+GUSf/UVe579UyrsPVCO1EaYgQ5b9KNhgdoDtfsb6OQTj9LKkmHHI72BKliIrhIx2b5H0rFXGCYNF3Aa8nC9Cm5mx0fEElayklGng9u+pvOJwDg= In-Reply-To: <000000000000a573da058858083c@google.com> Content-Language: en-US Content-ID: <5ABAAF49F10CC241A744BA0F8295D68F@namprd15.prod.outlook.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: To: syzbot Cc: "ast@kernel.org" , "bpf@vger.kernel.org" , "cgroups@vger.kernel.org" , "daniel@iogearbox.net" , "hannes@cmpxchg.org" , Martin Lau , "linux-kernel@vger.kernel.org" , "lizefan@huawei.com" , "netdev@vger.kernel.org" , Song Liu , "syzkaller-bugs@googlegroups.com" , "tj@kernel.org" , Yonghong Song Hi! I'm aware of this problem and presumably know where it comes from. I expect= that https://github.com/rgushchin/linux/commit/b1b6d210789ac0f5d83fd45fdab35eba1= 3cd2ce8 will fix it. I'll post it upstream tomorrow after some additional checks. Thanks! Roman On Tue, May 07, 2019 at 08:36:07PM -0700, syzbot wrote: > Hello, >=20 > syzbot found the following crash on: >=20 > HEAD commit: 00c3bc00 Add linux-next specific files for 20190507 > git tree: linux-next > console output: https://urldefense.proofpoint.com/v2/url?u=3Dhttps-3A__sy= zkaller.appspot.com_x_log.txt-3Fx-3D15220ec8a00000&d=3DDwIBaQ&c=3D5VD0RTtNl= Th3ycd41b3MUw&r=3DjJYgtDM7QT-W-Fz_d29HYQ&m=3D4iaRvebxGXyCS0fK4EQzBl8b5C4bdR= pBidLVWLI_GuM&s=3DhD1Gj5E63Z0nnx5OQgxeVKb91lJkZHE3qat1sAGP1ZI&e=3D > kernel config: https://urldefense.proofpoint.com/v2/url?u=3Dhttps-3A__sy= zkaller.appspot.com_x_.config-3Fx-3D63cd766601c6c9fc&d=3DDwIBaQ&c=3D5VD0RTt= NlTh3ycd41b3MUw&r=3DjJYgtDM7QT-W-Fz_d29HYQ&m=3D4iaRvebxGXyCS0fK4EQzBl8b5C4b= dRpBidLVWLI_GuM&s=3D_232tg9h9GVIkU_E6zSkqXt_VzdcnBSpy_oTxiER55s&e=3D > dashboard link: https://urldefense.proofpoint.com/v2/url?u=3Dhttps-3A__sy= zkaller.appspot.com_bug-3Fextid-3Df14868630901fc6151d3&d=3DDwIBaQ&c=3D5VD0R= TtNlTh3ycd41b3MUw&r=3DjJYgtDM7QT-W-Fz_d29HYQ&m=3D4iaRvebxGXyCS0fK4EQzBl8b5C= 4bdRpBidLVWLI_GuM&s=3DodzDbHDodu7xVLUX5bYH4hZS4TDEJ_Q-Wda-pamijDo&e=3D > compiler: gcc (GCC) 9.0.0 20181231 (experimental) > syz repro: https://urldefense.proofpoint.com/v2/url?u=3Dhttps-3A__sy= zkaller.appspot.com_x_repro.syz-3Fx-3D10fcf758a00000&d=3DDwIBaQ&c=3D5VD0RTt= NlTh3ycd41b3MUw&r=3DjJYgtDM7QT-W-Fz_d29HYQ&m=3D4iaRvebxGXyCS0fK4EQzBl8b5C4b= dRpBidLVWLI_GuM&s=3DynJR0QYyNDxBMdGoc8vUawwmdbQQ4uGaH47E1lCToTw&e=3D > C reproducer: https://urldefense.proofpoint.com/v2/url?u=3Dhttps-3A__sy= zkaller.appspot.com_x_repro.c-3Fx-3D1202ffa4a00000&d=3DDwIBaQ&c=3D5VD0RTtNl= Th3ycd41b3MUw&r=3DjJYgtDM7QT-W-Fz_d29HYQ&m=3D4iaRvebxGXyCS0fK4EQzBl8b5C4bdR= pBidLVWLI_GuM&s=3DTOZmN6wU-5eoDmgsf8dUSHVHfd8PiXWMHtLF8zIfVR0&e=3D >=20 > IMPORTANT: if you fix the bug, please add the following tag to the commit= : > Reported-by: syzbot+f14868630901fc6151d3@syzkaller.appspotmail.com >=20 > WARNING: CPU: 0 PID: 8653 at kernel/cgroup/cgroup.c:6008 > cgroup_exit+0x51a/0x5d0 kernel/cgroup/cgroup.c:6008 > Kernel panic - not syncing: panic_on_warn set ... > CPU: 0 PID: 8653 Comm: syz-executor076 Not tainted 5.1.0-next-20190507 #2 > 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+0x172/0x1f0 lib/dump_stack.c:113 > panic+0x2cb/0x75a kernel/panic.c:218 > __warn.cold+0x20/0x47 kernel/panic.c:575 > report_bug+0x263/0x2b0 lib/bug.c:186 > fixup_bug arch/x86/kernel/traps.c:179 [inline] > fixup_bug arch/x86/kernel/traps.c:174 [inline] > do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:272 > do_invalid_op+0x37/0x50 arch/x86/kernel/traps.c:291 > invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:972 > RIP: 0010:cgroup_exit+0x51a/0x5d0 kernel/cgroup/cgroup.c:6008 > Code: 00 48 c7 c2 20 7f 6d 87 be d3 01 00 00 48 c7 c7 20 80 6d 87 c6 05 0= 1 > 93 f1 07 01 e8 fb 03 ed ff e9 b1 fb ff ff e8 96 f9 05 00 <0f> 0b e9 75 fc= ff > ff e8 8a f9 05 00 48 c7 c2 e0 82 6d 87 be 85 02 > RSP: 0018:ffff888086c17a80 EFLAGS: 00010093 > RAX: ffff88808e99a000 RBX: 0000000000000001 RCX: ffffffff816b0b5e > RDX: 0000000000000000 RSI: ffffffff816b0eea RDI: 0000000000000001 > RBP: ffff888086c17b18 R08: ffff88808e99a000 R09: ffffed1010d82f3e > R10: ffffed1010d82f3d R11: 0000000000000003 R12: ffff88808e99a000 > R13: ffff8880981c3200 R14: ffff888086c17af0 R15: 1ffff11010d82f52 > do_exit+0x97a/0x2fa0 kernel/exit.c:889 > do_group_exit+0x135/0x370 kernel/exit.c:980 > get_signal+0x425/0x2270 kernel/signal.c:2638 > do_signal+0x87/0x1900 arch/x86/kernel/signal.c:815 > exit_to_usermode_loop+0x244/0x2c0 arch/x86/entry/common.c:163 > prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline] > syscall_return_slowpath arch/x86/entry/common.c:276 [inline] > do_syscall_64+0x57e/0x670 arch/x86/entry/common.c:301 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > RIP: 0033:0x4471e9 > Code: e8 3c e6 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f= 7 > 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 ab 06 fc ff c3 66 2e 0f 1f 84 00 00 00 00 > RSP: 002b:00007f479f748db8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca > RAX: fffffffffffffe00 RBX: 00000000006dcc38 RCX: 00000000004471e9 > RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00000000006dcc38 > RBP: 00000000006dcc30 R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dcc3c > R13: 00007ffd1ab0c31f R14: 00007f479f7499c0 R15: 0000000000000001 > Shutting down cpus with NMI > Kernel Offset: disabled > Rebooting in 86400 seconds.. >=20 >=20 > --- > This bug is generated by a bot. It may contain errors. > See https://urldefense.proofpoint.com/v2/url?u=3Dhttps-3A__goo.gl_tpsmEJ&= d=3DDwIBaQ&c=3D5VD0RTtNlTh3ycd41b3MUw&r=3DjJYgtDM7QT-W-Fz_d29HYQ&m=3D4iaRve= bxGXyCS0fK4EQzBl8b5C4bdRpBidLVWLI_GuM&s=3D-w9lCOsM40BNPAQbJETOta_aO2oUunuWH= F7_HEF_s4M&e=3D for more information about syzbot. > syzbot engineers can be reached at syzkaller@googlegroups.com. >=20 > syzbot will keep track of this bug report. See: > https://urldefense.proofpoint.com/v2/url?u=3Dhttps-3A__goo.gl_tpsmEJ-23st= atus&d=3DDwIBaQ&c=3D5VD0RTtNlTh3ycd41b3MUw&r=3DjJYgtDM7QT-W-Fz_d29HYQ&m=3D4= iaRvebxGXyCS0fK4EQzBl8b5C4bdRpBidLVWLI_GuM&s=3DwbPAdt5WlkacKUJ6S-HTGGEVDOC1= zOhIrPgSCdOq3UI&e=3D for how to communicate with syzbot. > syzbot can test patches for this bug, for details see: > https://urldefense.proofpoint.com/v2/url?u=3Dhttps-3A__goo.gl_tpsmEJ-23te= sting-2Dpatches&d=3DDwIBaQ&c=3D5VD0RTtNlTh3ycd41b3MUw&r=3DjJYgtDM7QT-W-Fz_d= 29HYQ&m=3D4iaRvebxGXyCS0fK4EQzBl8b5C4bdRpBidLVWLI_GuM&s=3DOmC7nK5BIF4c92BuG= G7AK2hjFHZhajxJG-VJh0jJRvc&e=3D