Wei Fang a48e232210 net: stmmac: fix the crash issue for zero copy XDP_TX action
There is a crash issue when running zero copy XDP_TX action, the crash
log is shown below.

[  216.122464] Unable to handle kernel paging request at virtual address fffeffff80000000
[  216.187524] Internal error: Oops: 0000000096000144 [#1]  SMP
[  216.301694] Call trace:
[  216.304130]  dcache_clean_poc+0x20/0x38 (P)
[  216.308308]  __dma_sync_single_for_device+0x1bc/0x1e0
[  216.313351]  stmmac_xdp_xmit_xdpf+0x354/0x400
[  216.317701]  __stmmac_xdp_run_prog+0x164/0x368
[  216.322139]  stmmac_napi_poll_rxtx+0xba8/0xf00
[  216.326576]  __napi_poll+0x40/0x218
[  216.408054] Kernel panic - not syncing: Oops: Fatal exception in interrupt

For XDP_TX action, the xdp_buff is converted to xdp_frame by
xdp_convert_buff_to_frame(). The memory type of the resulting xdp_frame
depends on the memory type of the xdp_buff. For page pool based xdp_buff
it produces xdp_frame with memory type MEM_TYPE_PAGE_POOL. For zero copy
XSK pool based xdp_buff it produces xdp_frame with memory type
MEM_TYPE_PAGE_ORDER0. However, stmmac_xdp_xmit_back() does not check the
memory type and always uses the page pool type, this leads to invalid
mappings and causes the crash. Therefore, check the xdp_buff memory type
in stmmac_xdp_xmit_back() to fix this issue.

Fixes: bba2556efa ("net: stmmac: Enable RX via AF_XDP zero-copy")
Signed-off-by: Wei Fang <wei.fang@nxp.com>
Reviewed-by: Hariprasad Kelam <hkelam@marvell.com>
Link: https://patch.msgid.link/20251204071332.1907111-1-wei.fang@nxp.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-12-29 17:35:36 +01:00

Linux kernel
============

The Linux kernel is the core of any Linux operating system. It manages hardware,
system resources, and provides the fundamental services for all other software.

Quick Start
-----------

* Report a bug: See Documentation/admin-guide/reporting-issues.rst
* Get the latest kernel: https://kernel.org
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* Join the community: https://lore.kernel.org/

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-----------------------

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* Building requirements: Documentation/process/changes.rst
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============

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For Specific Users
==================

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--------------------

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* Getting Started: Documentation/process/development-process.rst
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* Kernel Hacking Guide: Documentation/kernel-hacking/hacking.rst
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-------------------

Explore the kernel's architecture and internals:

* Researcher Guidelines: Documentation/process/researcher-guidelines.rst
* Memory Management: Documentation/mm/index.rst
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* Networking Stack: Documentation/networking/index.rst
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---------------

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-----------------------------

Maintain and stabilize kernel versions:

* Stable Kernel Rules: Documentation/process/stable-kernel-rules.rst
* Backporting Guide: Documentation/process/backporting.rst
* Applying Patches: Documentation/process/applying-patches.rst
* Subsystem Profile: Documentation/maintainer/maintainer-entry-profile.rst
* Git for Maintainers: Documentation/maintainer/configure-git.rst

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--------------------

Configure, tune, and troubleshoot Linux systems:

* Admin Guide: Documentation/admin-guide/index.rst
* Kernel Parameters: Documentation/admin-guide/kernel-parameters.rst
* Sysctl Tuning: Documentation/admin-guide/sysctl/index.rst
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----------

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* Maintainer Handbook: Documentation/maintainer/index.rst
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---------------

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* Driver API Guide: Documentation/driver-api/index.rst
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* DMA API: Documentation/core-api/dma-api.rst

Distribution Maintainer
-----------------------

Package and distribute the kernel:

* Stable Kernel Rules: Documentation/process/stable-kernel-rules.rst
* ABI Documentation: Documentation/ABI/README
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=========================

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