syzbot


WARNING in enqueue_task_dl

Status: fixed on 2020/07/13 20:03
Reported-by: syzbot+5dc1b5289479c434cd72@syzkaller.appspotmail.com
Fix commit: edf55b5e3bde sched/deadline: Initialize ->dl_boosted
First crash: 1822d, last: 1492d
Fix bisection: fixed by (bisect log) :
commit edf55b5e3bde2fdba1a304b8e069154a4312f566
Author: Juri Lelli <juri.lelli@redhat.com>
Date: Wed Jun 17 07:29:19 2020 +0000

  sched/deadline: Initialize ->dl_boosted

  
Similar bugs (3)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-414 WARNING in enqueue_task_dl syz 2 2022d 1922d 0/1 public: reported syz repro on 2019/04/10 16:04
linux-4.14 WARNING in enqueue_task_dl C inconclusive 1 1506d 1821d 0/1 upstream: reported C repro on 2019/07/20 08:10
upstream WARNING in enqueue_task_dl kernel C done 13 1488d 2065d 15/27 fixed on 2020/08/01 00:48
Fix bisection attempts (8)
Created Duration User Patch Repo Result
2020/07/13 10:38 3h22m bisect fix linux-4.19.y OK (1) job log
2020/06/13 09:42 23m bisect fix linux-4.19.y OK (0) job log log
2020/05/14 07:46 25m bisect fix linux-4.19.y OK (0) job log log
2020/04/14 07:11 24m bisect fix linux-4.19.y OK (0) job log log
2020/03/15 06:34 26m bisect fix linux-4.19.y OK (0) job log log
2020/02/14 05:57 24m bisect fix linux-4.19.y OK (0) job log log
2020/01/15 05:27 24m bisect fix linux-4.19.y OK (0) job log log
2019/12/16 04:53 24m bisect fix linux-4.19.y OK (0) job log log

Sample crash report:
8021q: adding VLAN 0 to HW filter on device batadv0
audit: type=1400 audit(1563597104.508:38): avc:  denied  { associate } for  pid=7611 comm="syz-executor.0" name="syz0" scontext=unconfined_u:object_r:unlabeled_t:s0 tcontext=system_u:object_r:unlabeled_t:s0 tclass=filesystem permissive=1
WARNING: CPU: 1 PID: 7620 at kernel/sched/deadline.c:627 rt_mutex_get_top_task /./include/linux/sched/rt.h:38 [inline]
WARNING: CPU: 1 PID: 7620 at kernel/sched/deadline.c:627 enqueue_task_dl+0x1c53/0x2d70 /kernel/sched/deadline.c:1441
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 7620 Comm: syz-executor.0 Not tainted 4.19.59 #32
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+0x263/0x507 /kernel/panic.c:185
 __warn.cold+0x20/0x4a /kernel/panic.c:540
 report_bug+0x263/0x2b0 /lib/bug.c:186
 fixup_bug /arch/x86/kernel/traps.c:178 [inline]
 fixup_bug /arch/x86/kernel/traps.c:173 [inline]
 do_error_trap+0x204/0x360 /arch/x86/kernel/traps.c:296
 do_invalid_op+0x1b/0x20 /arch/x86/kernel/traps.c:316
 invalid_op+0x14/0x20 /arch/x86/entry/entry_64.S:1013
RIP: 0010:setup_new_dl_entity /kernel/sched/deadline.c:627 [inline]
RIP: 0010:enqueue_dl_entity /kernel/sched/deadline.c:1428 [inline]
RIP: 0010:enqueue_task_dl+0x1c53/0x2d70 /kernel/sched/deadline.c:1499
Code: 37 00 48 c1 ea 03 48 c1 e0 2a 80 3c 02 00 0f 85 bc 0a 00 00 49 8b 85 50 0a 00 00 e9 e1 f5 ff ff e8 82 eb 51 00 e9 e9 e3 ff ff <0f> 0b e9 23 f5 ff ff 0f 0b e9 88 f5 ff ff 4c 89 4d b0 4c 89 45 b8
RSP: 0018:ffff88809fb47c90 EFLAGS: 00010002
RAX: 0000000000000000 RBX: ffffffff88b09b00 RCX: 0000000000000002
RDX: 0000000c78d28814 RSI: 1ffffffff10965dd RDI: ffffffff884b2ee8
RBP: ffff88809fb47d08 R08: ffff88807f20e2f8 R09: ffff88807f20e340
R10: ffff88807f20e0bc R11: ffff8880ae923993 R12: ffff88807f20e080
R13: ffff8880ae92d240 R14: ffff8880ae92d240 R15: ffff88807f20e34c
 enqueue_task+0xa0/0x1d0 /kernel/sched/core.c:728
 __sched_setscheduler+0xd35/0x1d90 /kernel/sched/core.c:4338
 sched_setattr /kernel/sched/core.c:4396 [inline]
 __do_sys_sched_setattr /kernel/sched/core.c:4572 [inline]
 __se_sys_sched_setattr /kernel/sched/core.c:4551 [inline]
 __x64_sys_sched_setattr+0x184/0x2b0 /kernel/sched/core.c:4551
 do_syscall_64+0xfd/0x620 /arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x459819
Code: fd b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f125bf71c78 EFLAGS: 00000246 ORIG_RAX: 000000000000013a
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459819
RDX: 0000000000000000 RSI: 0000000020000000 RDI: 0000000000000000
RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f125bf726d4
R13: 00000000004c6d52 R14: 00000000004dc010 R15: 00000000ffffffff

======================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/07/20 04:35 linux-4.19.y 3bd837bfe431 1656845f .config console log report syz ci2-linux-4-19
* Struck through repros no longer work on HEAD.