Hi! I'm aware of this problem and presumably know where it comes from. I expect that https://github.com/rgushchin/linux/commit/b1b6d210789ac0f5d83fd45fdab35eba13cd2ce8 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, > > syzbot found the following crash on: > > HEAD commit: 00c3bc00 Add linux-next specific files for 20190507 > git tree: linux-next > console output: https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_log.txt-3Fx-3D15220ec8a00000&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=jJYgtDM7QT-W-Fz_d29HYQ&m=4iaRvebxGXyCS0fK4EQzBl8b5C4bdRpBidLVWLI_GuM&s=hD1Gj5E63Z0nnx5OQgxeVKb91lJkZHE3qat1sAGP1ZI&e= > kernel config: https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_.config-3Fx-3D63cd766601c6c9fc&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=jJYgtDM7QT-W-Fz_d29HYQ&m=4iaRvebxGXyCS0fK4EQzBl8b5C4bdRpBidLVWLI_GuM&s=_232tg9h9GVIkU_E6zSkqXt_VzdcnBSpy_oTxiER55s&e= > dashboard link: https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_bug-3Fextid-3Df14868630901fc6151d3&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=jJYgtDM7QT-W-Fz_d29HYQ&m=4iaRvebxGXyCS0fK4EQzBl8b5C4bdRpBidLVWLI_GuM&s=odzDbHDodu7xVLUX5bYH4hZS4TDEJ_Q-Wda-pamijDo&e= > compiler: gcc (GCC) 9.0.0 20181231 (experimental) > syz repro: https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_repro.syz-3Fx-3D10fcf758a00000&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=jJYgtDM7QT-W-Fz_d29HYQ&m=4iaRvebxGXyCS0fK4EQzBl8b5C4bdRpBidLVWLI_GuM&s=ynJR0QYyNDxBMdGoc8vUawwmdbQQ4uGaH47E1lCToTw&e= > C reproducer: https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_repro.c-3Fx-3D1202ffa4a00000&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=jJYgtDM7QT-W-Fz_d29HYQ&m=4iaRvebxGXyCS0fK4EQzBl8b5C4bdRpBidLVWLI_GuM&s=TOZmN6wU-5eoDmgsf8dUSHVHfd8PiXWMHtLF8zIfVR0&e= > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+f14868630901fc6151d3@xxxxxxxxxxxxxxxxxxxxxxxxx > > 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 01 > 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 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 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.. > > > --- > This bug is generated by a bot. It may contain errors. > See https://urldefense.proofpoint.com/v2/url?u=https-3A__goo.gl_tpsmEJ&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=jJYgtDM7QT-W-Fz_d29HYQ&m=4iaRvebxGXyCS0fK4EQzBl8b5C4bdRpBidLVWLI_GuM&s=-w9lCOsM40BNPAQbJETOta_aO2oUunuWHF7_HEF_s4M&e= for more information about syzbot. > syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. > > syzbot will keep track of this bug report. See: > https://urldefense.proofpoint.com/v2/url?u=https-3A__goo.gl_tpsmEJ-23status&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=jJYgtDM7QT-W-Fz_d29HYQ&m=4iaRvebxGXyCS0fK4EQzBl8b5C4bdRpBidLVWLI_GuM&s=wbPAdt5WlkacKUJ6S-HTGGEVDOC1zOhIrPgSCdOq3UI&e= for how to communicate with syzbot. > syzbot can test patches for this bug, for details see: > https://urldefense.proofpoint.com/v2/url?u=https-3A__goo.gl_tpsmEJ-23testing-2Dpatches&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=jJYgtDM7QT-W-Fz_d29HYQ&m=4iaRvebxGXyCS0fK4EQzBl8b5C4bdRpBidLVWLI_GuM&s=OmC7nK5BIF4c92BuGG7AK2hjFHZhajxJG-VJh0jJRvc&e=
