Re: next-20250623: arm64 devices kernel panic Internal error Oops at pidfs_free_pid (fs/pidfs.c:162)

[Christian Brauner]

On Mon, Jun 23, 2025 at 05:29:38PM +0530, Naresh Kamboju wrote:
> Regressions on arm64 devices and qemu-arm64 while running LTP controllers
> and selftests cgroup test cases the following kernel Panic Internal error oops
> found on the Linux next-20250623 tag.
> 
> Regressions found on arm64 device
>   - Kernel Panic Internal oops @ LTP controllers
>   - Kernel Panic Internal oops @ selftest cgroups
> 
> Test environments:
>  - Dragonboard-410c
>  - e850-96
>  - FVP
>  - Juno-r2
>  - rk3399-rock-pi-4b
>  - qemu-arm64
> 
> Regression Analysis:
>  - New regression? Yes
>  - Reproducibility? Yes
> 
> Boot regression: arm64 devices kernel panic Internal error Oops at
> pidfs_free_pid (fs/pidfs.c:162)
> 
> Reported-by: Linux Kernel Functional Testing <lkft@xxxxxxxxxx>
> 
> ## Test log
> [   67.087303] Internal error: Oops: 0000000096000004 [#1]  SMP
> [   67.094021] Modules linked in: snd_soc_hdmi_codec venus_enc
> venus_dec videobuf2_dma_contig pm8916_wdt qcom_wcnss_pil
> coresight_cpu_debug coresight_tmc coresight_replicator qcom_camss
> coresight_stm snd_soc_lpass_apq8016 msm qrtr coresight_funnel
> snd_soc_msm8916_digital snd_soc_lpass_cpu coresight_tpiu
> snd_soc_msm8916_analog videobuf2_dma_sg stm_core coresight_cti
> snd_soc_lpass_platform snd_soc_apq8016_sbc venus_core
> snd_soc_qcom_common qcom_q6v5_mss v4l2_fwnode coresight snd_soc_core
> qcom_pil_info v4l2_async snd_compress llcc_qcom snd_pcm_dmaengine
> ocmem qcom_q6v5 v4l2_mem2mem videobuf2_memops snd_pcm qcom_sysmon
> drm_exec adv7511 snd_timer videobuf2_v4l2 gpu_sched qcom_common snd
> videodev drm_dp_aux_bus qcom_glink_smem soundcore qcom_spmi_vadc
> mdt_loader drm_display_helper qnoc_msm8916 qmi_helpers
> videobuf2_common qcom_vadc_common qcom_spmi_temp_alarm rtc_pm8xxx
> qcom_pon qcom_stats mc cec drm_client_lib qcom_rng rpmsg_ctrl
> display_connector rpmsg_char phy_qcom_usb_hs socinfo drm_kms_helper
> rmtfs_mem ramoops
> [   67.094437]  reed_solomon fuse drm backlight ip_tables x_tables
> [   67.189084] CPU: 3 UID: 0 PID: 0 Comm: swapper/3 Not tainted
> 6.16.0-rc3-next-20250623 #1 PREEMPT
> [   67.194810] Hardware name: Qualcomm Technologies, Inc. APQ 8016 SBC (DT)
> [   67.234078] pc : pidfs_free_pid (fs/pidfs.c:162)

Thanks, I see the issue. I'm pushing out a fix. Please let me know if
that reproduces in the next few days.