Subject: WARNING in cgroup_apply_control_disable

From: syzbot <[email-masked]>
Date: Tue, 21 Apr 2020 02:36:14 -0700

Hello,

syzbot found the following crash on:

HEAD commit:    7a56db02 Merge tag 'nfs-for-5.7-3' of git://git.linux-nfs...
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=11e336abe00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=5d351a1019ed81a2
dashboard link: https://syzkaller.appspot.com/bug?extid=5b142e89a1b402a24801
compiler:       gcc (GCC) 9.0.0 20181231 (experimental)
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=10f0c6abe00000

Bisection is inconclusive: the bug happens on the oldest tested release.

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=1113ec5fe00000
final crash:    https://syzkaller.appspot.com/x/report.txt?x=1313ec5fe00000
console output: https://syzkaller.appspot.com/x/log.txt?x=1513ec5fe00000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: [email-masked]

------------[ cut here ]------------
WARNING: CPU: 0 PID: 8613 at kernel/cgroup/cgroup.c:3111 cgroup_apply_control_disable+0x404/0x4d0 kernel/cgroup/cgroup.c:3111
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 8613 Comm: syz-executor.1 Not tainted 5.7.0-rc1-syzkaller #0
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+0x188/0x20d lib/dump_stack.c:118
 panic+0x2e3/0x75c kernel/panic.c:221
 __warn.cold+0x2f/0x35 kernel/panic.c:582
 report_bug+0x27b/0x2f0 lib/bug.c:195
 fixup_bug arch/x86/kernel/traps.c:175 [inline]
 fixup_bug arch/x86/kernel/traps.c:170 [inline]
 do_error_trap+0x12b/0x220 arch/x86/kernel/traps.c:267
 do_invalid_op+0x32/0x40 arch/x86/kernel/traps.c:286
 invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1027
RIP: 0010:cgroup_apply_control_disable+0x404/0x4d0 kernel/cgroup/cgroup.c:3111
Code: ff ff ff e8 5e 9c 06 00 48 89 ef 41 ff d5 e9 1a ff ff ff e8 4e 9c 06 00 48 89 ef e8 b6 e5 fe ff e9 08 ff ff ff e8 3c 9c 06 00 <0f> 0b e9 ab fd ff ff 48 83 c4 30 5b 5d 41 5c 41 5d 41 5e 41 5f e9
RSP: 0018:ffffc90005247a90 EFLAGS: 00010293
RAX: ffff888096aba5c0 RBX: dffffc0000000000 RCX: ffffffff816c956d
RDX: 0000000000000000 RSI: ffffffff816c97c4 RDI: 0000000000000007
RBP: ffff8880a601b000 R08: ffff888096aba5c0 R09: ffffed1015cc7104
R10: ffff8880ae63881b R11: ffffed1015cc7103 R12: 0000000000000008
R13: 0000000000000002 R14: ffffffff89a30640 R15: ffff8880917de000
 cgroup_finalize_control kernel/cgroup/cgroup.c:3178 [inline]
 rebind_subsystems+0x3cd/0xb00 kernel/cgroup/cgroup.c:1750
 cgroup_setup_root+0x36a/0xa30 kernel/cgroup/cgroup.c:1984
 cgroup1_root_to_use kernel/cgroup/cgroup-v1.c:1190 [inline]
 cgroup1_get_tree+0xd69/0x13b6 kernel/cgroup/cgroup-v1.c:1207
 vfs_get_tree+0x89/0x2f0 fs/super.c:1547
 do_new_mount fs/namespace.c:2816 [inline]
 do_mount+0x1306/0x1b30 fs/namespace.c:3141
 __do_sys_mount fs/namespace.c:3350 [inline]
 __se_sys_mount fs/namespace.c:3327 [inline]
 __x64_sys_mount+0x18f/0x230 fs/namespace.c:3327
 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x49/0xb3
RIP: 0033:0x45f2da
Code: b8 a6 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 4d 8c fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 2a 8c fb ff c3 66 0f 1f 84 00 00 00 00 00
RSP: 002b:00007ffc7dbf09e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ffc7dbf0a40 RCX: 000000000045f2da
RDX: 00000000004cad69 RSI: 00000000004c1465 RDI: 00000000004c1428
RBP: 0000000000000000 R08: 00000000004cf6b0 R09: 000000000000001c
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000418390
R13: 00007ffc7dbf0c68 R14: 0000000000000000 R15: 0000000000000000
Kernel Offset: disabled
Rebooting in 86400 seconds..

---
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