syzbot


KASAN: stack-out-of-bounds Read in select_task_rq_fair

Status: fixed on 2019/03/06 07:43
Subsystems: kernel
[Documentation on labels]
Fix commit: 44039e00171b fou6: Prevent unbounded recursion in GUE error handler
First crash: 1996d, last: 1987d

Sample crash report:
==================================================================
kasan: CONFIG_KASAN_INLINE enabled
BUG: KASAN: stack-out-of-bounds in select_task_rq_fair+0x2b5d/0x3b60 kernel/sched/fair.c:6624
kasan: GPF could be caused by NULL-ptr deref or user memory access
Read of size 4 at addr ffff8880a9dd12cc by task syz-executor3/7890
general protection fault: 0000 [#1] PREEMPT SMP KASAN

CPU: 0 PID: -1478884216 Comm: V
 Not tainted 4.20.0+ #3
CPU: 1 PID: 7890 Comm: syz-executor3 Not tainted 4.20.0+ #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__read_once_size include/linux/compiler.h:191 [inline]
RIP: 0010:get_running_cputimer include/linux/sched/cputime.h:85 [inline]
RIP: 0010:account_group_system_time include/linux/sched/cputime.h:149 [inline]
RIP: 0010:account_system_index_time+0xe8/0x5f0 kernel/sched/cputime.c:168
Call Trace:
Code: 04 00 00 49 8b 84 24 00 07 00 00 48 ba 00 00 00 00 00 fc ff df 48 8d b8 40 01 00 00 48 8d 88 28 01 00 00 48 89 fe 48 c1 ee 03 <0f> b6 14 16 48 89 fe 83 e6 07 40 38 f2 7f 08 84 d2 0f 85 93 03 00
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1db/0x2d0 lib/dump_stack.c:113
RSP: 0018:ffff8880ae607a80 EFLAGS: 00010006
RAX: 0000000000000000 RBX: 1ffff11015cc0f54 RCX: 0000000000000128
RDX: dffffc0000000000 RSI: 0000000000000028 RDI: 0000000000000140
 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:256
RBP: ffff8880ae607b48 R08: ffff8880ae61f5f0 R09: ffffffff8a99f01d
R10: ffffffff8a99f010 R11: 0000000000000001 R12: ffff8880a9e62240
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report mm/kasan/report.c:412 [inline]
 kasan_report.cold+0x8c/0x2ba mm/kasan/report.c:396
R13: 000000000094301b R14: 0000000000000003 R15: ffff8880ae607b20
 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:432
FS:  0000000000000000(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000
 select_task_rq_fair+0x2b5d/0x3b60 kernel/sched/fair.c:6624
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000068 CR3: 00000000958a7000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 irqtime_account_process_tick.isra.0+0x3a2/0x490 kernel/sched/cputime.c:380
 account_process_tick+0x27f/0x350 kernel/sched/cputime.c:483
 select_task_rq kernel/sched/core.c:1536 [inline]
 wake_up_new_task+0x212/0xd30 kernel/sched/core.c:2417
 update_process_times+0x25/0x80 kernel/time/timer.c:1633
 tick_sched_handle+0xa2/0x190 kernel/time/tick-sched.c:161
 tick_sched_timer+0x47/0x130 kernel/time/tick-sched.c:1271
 __run_hrtimer kernel/time/hrtimer.c:1389 [inline]
 __hrtimer_run_queues+0x3a7/0x1050 kernel/time/hrtimer.c:1451
 _do_fork+0x2a5/0x1170 kernel/fork.c:2246
 hrtimer_interrupt+0x314/0x770 kernel/time/hrtimer.c:1509
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1035 [inline]
 smp_apic_timer_interrupt+0x18d/0x760 arch/x86/kernel/apic/apic.c:1060
 __do_sys_clone kernel/fork.c:2328 [inline]
 __se_sys_clone kernel/fork.c:2322 [inline]
 __x64_sys_clone+0xbf/0x150 kernel/fork.c:2322
 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807
 </IRQ>
Modules linked in:

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

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/01/15 00:34 net-next-old b71acb0e3721 ebacf5cb .config console log report ci-upstream-net-kasan-gce
2019/01/06 03:09 net-next-old b71acb0e3721 53be0a37 .config console log report ci-upstream-net-kasan-gce
* Struck through repros no longer work on HEAD.