AW: [syzbot] [ext4?] general protection fault in hrtimer_nanosleep

[carsten.schmid@xxxxxxxxxxx]

Hi,

> [  125.919060][    C0] BUG: KASAN: stack-out-of-bounds in rb_next+0x10a/0x130
> [  125.921169][    C0] Read of size 8 at addr ffffc900048e7c60 by task kworker/0:1/9
> [  125.923235][    C0]
> [  125.923243][    C0] CPU: 0 PID: 9 Comm: kworker/0:1 Not tainted 6.6.0-rc7-syzkaller-00142-g888cf78c29e2 #0
> [  125.924546][    C0] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
> [  125.926915][    C0] Workqueue: events nsim_dev_trap_report_work
> [  125.929333][    C0]
> [  125.929341][    C0] Call Trace:
> [  125.929350][    C0]  <IRQ>
> [  125.929356][    C0]  dump_stack_lvl+0xd9/0x1b0
> [  125.931302][    C0]  print_report+0xc4/0x620
> [  125.932115][    C0]  ? __virt_addr_valid+0x5e/0x2d0
> [  125.933194][    C0]  kasan_report+0xda/0x110
> [  125.934814][    C0]  ? rb_next+0x10a/0x130
> [  125.936521][    C0]  ? rb_next+0x10a/0x130
> [  125.936544][    C0]  rb_next+0x10a/0x130
> [  125.936565][    C0]  timerqueue_del+0xd4/0x140
> [  125.936590][    C0]  __remove_hrtimer+0x99/0x290
> [  125.936613][    C0]  __hrtimer_run_queues+0x55b/0xc10
> [  125.936638][    C0]  ? enqueue_hrtimer+0x310/0x310
> [  125.936659][    C0]  ? ktime_get_update_offsets_now+0x3bc/0x610
> [  125.936688][    C0]  hrtimer_interrupt+0x31b/0x800
> [  125.936715][    C0]  __sysvec_apic_timer_interrupt+0x105/0x3f0
> [  125.936737][    C0]  sysvec_apic_timer_interrupt+0x8e/0xc0
> [  125.936755][    C0]  </IRQ>
> [  125.936759][    C0]  <TASK>

i had sporadic similar issues with 4.14 kernels (several maturities, .147  .212  .247  .300) in the past 5 years where stack looked quite similar:

[  432.041880] general protection fault: 0000 [#1] PREEMPT SMP NOPTI
[  432.048697] Modules linked in: intel_tfm_governor ecryptfs coretemp i2c_i801 sbi_apl snd_soc_skl sdw_cnl snd_soc_acpi_intel_match snd_soc_acpi snd_soc_core snd_compress snd_soc_skl_ipc xhci_pci xhci_hcd sdw_bus crc8 ahci snd_soc_sst_ipc snd_soc_sst_dsp snd_hda_ext_core libahci snd_hda_core libata snd_pcm usbcore mei_me snd_timer scsi_mod usb_common snd mei soundcore fuse 8021q inap560t(O) i915 video backlight intel_gtt i2c_algo_bit drm_kms_helper drm firmware_class igb_avb(O) ptp hwmon spi_pxa2xx_platform pps_core
[  432.099672] CPU: 3 PID: 5729 Comm: dlt_segmented Tainted: G     U     O    4.14.244-apl #1
[  432.108909] task: 00000000504d2561 task.stack: 000000007d0046fd
[  432.115530] RIP: 0010:rb_erase_cached+0x31/0x3b0
[  432.120683] RSP: 0018:ffffa31d84f77d40 EFLAGS: 00010006
[  432.126517] RAX: 0000000000000001 RBX: ffffa31d84f77e30 RCX: 0000000000000000
[  432.134485] RDX: 0000000000000000 RSI: ffff9ed077c1bb10 RDI: ffffa31d84f77e30
[  432.142456] RBP: ffffa31d84f77d40 R08: ffffa31d84f77e30 R09: 0000a31d80a77c90
[  432.150426] R10: ffff9ed077c1bee0 R11: 0000000000000400 R12: ffff9ed077c1bb10
[  432.158394] R13: 0000000000000000 R14: ffff9ed077c1bac0 R15: 0000000000000000
[  432.166366] FS:  00007ff718cce700(0000) GS:ffff9ed077d80000(0000) knlGS:0000000000000000
[  432.175403] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  432.181819] CR2: 00007ff7182ca3e4 CR3: 000000026175c000 CR4: 00000000003406a0
[  432.189790] Call Trace:
[  432.192526]  timerqueue_del+0x1d/0x40
[  432.196617]  __remove_hrtimer+0x37/0x70
[  432.200898]  hrtimer_try_to_cancel+0xa0/0x120
[  432.205769]  do_nanosleep+0xa9/0x180
[  432.209765]  ? kfree+0x169/0x180
[  432.213370]  hrtimer_nanosleep+0xbb/0x150
[  432.217849]  ? hrtimer_init+0x110/0x110
[  432.222134]  SyS_nanosleep+0x6d/0xa0
[  432.226126]  do_syscall_64+0x79/0x350
[  432.230218]  entry_SYSCALL_64_after_hwframe+0x41/0xa6
[  432.235861] RIP: 0033:0x7ff7199b7240
[  432.239850] RSP: 002b:00007ff718ccddf0 EFLAGS: 00000293 ORIG_RAX: 0000000000000023
[  432.248309] RAX: ffffffffffffffda RBX: 00007ff718ccde20 RCX: 00007ff7199b7240
[  432.256282] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00007ff718ccde20
[  432.264252] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
[  432.272222] R10: 0000000000000000 R11: 0000000000000293 R12: 00007ffe333ec72e
[  432.280190] R13: 00007ffe333ec72f R14: 0000000000802000 R15: 00007ffe333ec730
[  432.288161] Code: 89 f8 4c 8b 4f 08 48 89 e5 4c 8b 57 10 74 0a 48 3b 7e 08 0f 84 a6 02 00 00 4d 85 d2 0f 84 28 02 00 00 4d 85 c9 0f 84 03 02 00 00 <49> 8b 51 10 4c 89 cf 4c 89 c8 48 85 d2 75 0b e9 65 02 00 00 48 
[  432.309346] RIP: rb_erase_cached+0x31/0x3b0 RSP: ffffa31d84f77d40

Looks like it's worth to dig inside that.
Unfortunately i wasn't able to reproduce this, and i'm still not. So i can't help digging but wanted to tell that this seems not to be related to a specific kernel ....

Thanks
Carsten
>>
>> Thanks,
>>
>>         tglx
>>