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Saeed Mahameed 4dadc4077e net/mlx5e: Fix crash on profile change rollback failure
mlx5e_netdev_change_profile can fail to attach a new profile and can
fail to rollback to old profile, in such case, we could end up with a
dangling netdev with a fully reset netdev_priv. A retry to change
profile, e.g. another attempt to call mlx5e_netdev_change_profile via
switchdev mode change, will crash trying to access the now NULL
priv->mdev.

This fix allows mlx5e_netdev_change_profile() to handle previous
failures and an empty priv, by not assuming priv is valid.

Pass netdev and mdev to all flows requiring
mlx5e_netdev_change_profile() and avoid passing priv.
In mlx5e_netdev_change_profile() check if current priv is valid, and if
not, just attach the new profile without trying to access the old one.

This fixes the following oops, when enabling switchdev mode for the 2nd
time after first time failure:

 ## Enabling switchdev mode first time:

mlx5_core 0012:03:00.1: E-Switch: Supported tc chains and prios offload
workqueue: Failed to create a rescuer kthread for wq "mlx5e": -EINTR
mlx5_core 0012:03:00.1: mlx5e_netdev_init_profile:6214:(pid 37199): mlx5e_priv_init failed, err=-12
mlx5_core 0012:03:00.1 gpu3rdma1: mlx5e_netdev_change_profile: new profile init failed, -12
workqueue: Failed to create a rescuer kthread for wq "mlx5e": -EINTR
mlx5_core 0012:03:00.1: mlx5e_netdev_init_profile:6214:(pid 37199): mlx5e_priv_init failed, err=-12
mlx5_core 0012:03:00.1 gpu3rdma1: mlx5e_netdev_change_profile: failed to rollback to orig profile, -12
                                                                         ^^^^^^^^
mlx5_core 0000:00:03.0: E-Switch: Disable: mode(LEGACY), nvfs(0), necvfs(0), active vports(0)

 ## retry: Enabling switchdev mode 2nd time:

mlx5_core 0000:00:03.0: E-Switch: Supported tc chains and prios offload
BUG: kernel NULL pointer dereference, address: 0000000000000038
 #PF: supervisor read access in kernel mode
 #PF: error_code(0x0000) - not-present page
PGD 0 P4D 0
Oops: Oops: 0000 [#1] SMP NOPTI
CPU: 13 UID: 0 PID: 520 Comm: devlink Not tainted 6.18.0-rc4+ #91 PREEMPT(voluntary)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-2.fc40 04/01/2014
RIP: 0010:mlx5e_detach_netdev+0x3c/0x90
Code: 50 00 00 f0 80 4f 78 02 48 8b bf e8 07 00 00 48 85 ff 74 16 48 8b 73 78 48 d1 ee 83 e6 01 83 f6 01 40 0f b6 f6 e8 c4 42 00 00 <48> 8b 45 38 48 85 c0 74 08 48 89 df e8 cc 47 40 1e 48 8b bb f0 07
RSP: 0018:ffffc90000673890 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff8881036a89c0 RCX: 0000000000000000
RDX: ffff888113f63800 RSI: ffffffff822fe720 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000002dcd R09: 0000000000000000
R10: ffffc900006738e8 R11: 00000000ffffffff R12: 0000000000000000
R13: 0000000000000000 R14: ffff8881036a89c0 R15: 0000000000000000
FS:  00007fdfb8384740(0000) GS:ffff88856a9d6000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000038 CR3: 0000000112ae0005 CR4: 0000000000370ef0
Call Trace:
 <TASK>
 mlx5e_netdev_change_profile+0x45/0xb0
 mlx5e_vport_rep_load+0x27b/0x2d0
 mlx5_esw_offloads_rep_load+0x72/0xf0
 esw_offloads_enable+0x5d0/0x970
 mlx5_eswitch_enable_locked+0x349/0x430
 ? is_mp_supported+0x57/0xb0
 mlx5_devlink_eswitch_mode_set+0x26b/0x430
 devlink_nl_eswitch_set_doit+0x6f/0xf0
 genl_family_rcv_msg_doit+0xe8/0x140
 genl_rcv_msg+0x18b/0x290
 ? __pfx_devlink_nl_pre_doit+0x10/0x10
 ? __pfx_devlink_nl_eswitch_set_doit+0x10/0x10
 ? __pfx_devlink_nl_post_doit+0x10/0x10
 ? __pfx_genl_rcv_msg+0x10/0x10
 netlink_rcv_skb+0x52/0x100
 genl_rcv+0x28/0x40
 netlink_unicast+0x282/0x3e0
 ? __alloc_skb+0xd6/0x190
 netlink_sendmsg+0x1f7/0x430
 __sys_sendto+0x213/0x220
 ? __sys_recvmsg+0x6a/0xd0
 __x64_sys_sendto+0x24/0x30
 do_syscall_64+0x50/0x1f0
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7fdfb8495047

Fixes: c4d7eb5768 ("net/mxl5e: Add change profile method")
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Link: https://patch.msgid.link/20260108212657.25090-2-saeed@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-10 15:21:09 -08:00
arch Fix the AMD microcode Entrysign signature checking code to include more 2026-01-02 12:04:51 -08:00
block block-6.19-20260102 2026-01-02 12:15:59 -08:00
certs sign-file,extract-cert: use pkcs11 provider for OPENSSL MAJOR >= 3 2024-09-20 19:52:48 +03:00
crypto crypto: seqiv - Do not use req->iv after crypto_aead_encrypt 2025-12-19 14:47:06 +08:00
Documentation netlink: specs: netdev: clarify the page pool API a little 2026-01-05 16:49:54 -08:00
drivers net/mlx5e: Fix crash on profile change rollback failure 2026-01-10 15:21:09 -08:00
fs nfsd-6.19 fixes: 2026-01-06 09:12:52 -08:00
include ipv4: ip_tunnel: spread netdev_lockdep_set_classes() 2026-01-08 18:02:35 -08:00
init Significant patch series in this pull request: 2025-12-06 14:01:20 -08:00
io_uring io_uring-6.19-20260102 2026-01-02 12:07:55 -08:00
ipc Significant patch series in this pull request: 2025-12-06 14:01:20 -08:00
kernel Power management fix for 6.19-rc4 2026-01-02 12:35:29 -08:00
lib idr: fix idr_alloc() returning an ID out of range 2025-12-23 11:23:11 -08:00
LICENSES LICENSES: Add modern form of the LGPL-2.1 tags to the usage guide section 2025-10-22 07:58:19 +02:00
mm mm/ksm: fix pte_unmap_unlock of wrong address in break_ksm_pmd_entry 2025-12-23 11:23:17 -08:00
net bluetooth pull request for net: 2026-01-10 14:32:01 -08:00
rust 27 hotfixes. 12 are cc:stable, 18 are MM. 2025-12-29 11:40:38 -08:00
samples samples/ftrace: Adjust LoongArch register restore order in direct calls 2025-12-31 15:19:25 +08:00
scripts mcb: Add missing modpost build support 2025-12-27 20:48:01 +01:00
security kernel/kexec: change the prototype of kimage_map_segment() 2025-12-23 11:23:13 -08:00
sound ALSA: hda/realtek: add HP Laptop 15s-eq1xxx mute LED quirk 2026-01-02 14:34:23 +01:00
tools vsock/test: add a final full barrier after run all tests 2026-01-10 12:07:25 -08:00
usr initramfs: add gen_init_cpio to hostprogs unconditionally 2025-11-26 21:55:40 +01:00
virt KVM fixes for 6.19-rc1 2025-12-18 18:38:45 +01:00
.clang-format s390/pci: Fix cyclic dead-lock in zpci_zdev_put() and zpci_scan_devices() 2025-12-14 11:03:58 +01:00
.clippy.toml rust: clean Rust 1.88.0's warning about clippy::disallowed_macros configuration 2025-05-07 00:11:47 +02:00
.cocciconfig
.editorconfig .editorconfig: remove trim_trailing_whitespace option 2024-06-13 16:47:52 +02:00
.get_maintainer.ignore MAINTAINERS: remove Alyssa Rosenzweig 2025-09-18 21:17:31 +02:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore rust: kbuild: add proc macro library support 2025-11-24 17:15:36 +01:00
.mailmap Including fixes from netfilter and wireless. 2026-01-08 08:40:35 -10:00
.pylintrc docs: Move the python libraries to tools/lib/python 2025-11-18 09:22:40 -07:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS Including fixes from netfilter and CAN. 2025-12-19 07:55:35 +12:00
Kbuild sched: Make migrate_{en,dis}able() inline 2025-09-25 09:57:16 +02:00
Kconfig io_uring: Rename KConfig to Kconfig 2025-02-19 14:53:27 -07:00
MAINTAINERS MAINTAINERS: add docs and selftest to the TLS file list 2026-01-08 11:52:46 -08:00
Makefile Linux 6.19-rc4 2026-01-04 14:41:55 -08:00
README README: restructure with role-based documentation and guidelines 2025-11-29 08:40:33 -07:00

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
* Build the kernel: See Documentation/admin-guide/quickly-build-trimmed-linux.rst
* Join the community: https://lore.kernel.org/

Essential Documentation
-----------------------

All users should be familiar with:

* Building requirements: Documentation/process/changes.rst
* Code of Conduct: Documentation/process/code-of-conduct.rst
* License: See COPYING

Documentation can be built with make htmldocs or viewed online at:
https://www.kernel.org/doc/html/latest/


Who Are You?
============

Find your role below:

* New Kernel Developer - Getting started with kernel development
* Academic Researcher - Studying kernel internals and architecture
* Security Expert - Hardening and vulnerability analysis
* Backport/Maintenance Engineer - Maintaining stable kernels
* System Administrator - Configuring and troubleshooting
* Maintainer - Leading subsystems and reviewing patches
* Hardware Vendor - Writing drivers for new hardware
* Distribution Maintainer - Packaging kernels for distros


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

New Kernel Developer
--------------------

Welcome! Start your kernel development journey here:

* Getting Started: Documentation/process/development-process.rst
* Your First Patch: Documentation/process/submitting-patches.rst
* Coding Style: Documentation/process/coding-style.rst
* Build System: Documentation/kbuild/index.rst
* Development Tools: Documentation/dev-tools/index.rst
* Kernel Hacking Guide: Documentation/kernel-hacking/hacking.rst
* Core APIs: Documentation/core-api/index.rst

Academic Researcher
-------------------

Explore the kernel's architecture and internals:

* Researcher Guidelines: Documentation/process/researcher-guidelines.rst
* Memory Management: Documentation/mm/index.rst
* Scheduler: Documentation/scheduler/index.rst
* Networking Stack: Documentation/networking/index.rst
* Filesystems: Documentation/filesystems/index.rst
* RCU (Read-Copy Update): Documentation/RCU/index.rst
* Locking Primitives: Documentation/locking/index.rst
* Power Management: Documentation/power/index.rst

Security Expert
---------------

Security documentation and hardening guides:

* Security Documentation: Documentation/security/index.rst
* LSM Development: Documentation/security/lsm-development.rst
* Self Protection: Documentation/security/self-protection.rst
* Reporting Vulnerabilities: Documentation/process/security-bugs.rst
* CVE Procedures: Documentation/process/cve.rst
* Embargoed Hardware Issues: Documentation/process/embargoed-hardware-issues.rst
* Security Features: Documentation/userspace-api/seccomp_filter.rst

Backport/Maintenance Engineer
-----------------------------

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

System Administrator
--------------------

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
* Tracing/Debugging: Documentation/trace/index.rst
* Performance Security: Documentation/admin-guide/perf-security.rst
* Hardware Monitoring: Documentation/hwmon/index.rst

Maintainer
----------

Lead kernel subsystems and manage contributions:

* Maintainer Handbook: Documentation/maintainer/index.rst
* Pull Requests: Documentation/maintainer/pull-requests.rst
* Managing Patches: Documentation/maintainer/modifying-patches.rst
* Rebasing and Merging: Documentation/maintainer/rebasing-and-merging.rst
* Development Process: Documentation/process/maintainer-handbooks.rst
* Maintainer Entry Profile: Documentation/maintainer/maintainer-entry-profile.rst
* Git Configuration: Documentation/maintainer/configure-git.rst

Hardware Vendor
---------------

Write drivers and support new hardware:

* Driver API Guide: Documentation/driver-api/index.rst
* Driver Model: Documentation/driver-api/driver-model/driver.rst
* Device Drivers: Documentation/driver-api/infrastructure.rst
* Bus Types: Documentation/driver-api/driver-model/bus.rst
* Device Tree Bindings: Documentation/devicetree/bindings/
* Power Management: Documentation/driver-api/pm/index.rst
* 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
* Kernel Configuration: Documentation/kbuild/kconfig.rst
* Module Signing: Documentation/admin-guide/module-signing.rst
* Kernel Parameters: Documentation/admin-guide/kernel-parameters.rst
* Tainted Kernels: Documentation/admin-guide/tainted-kernels.rst



Communication and Support
=========================

* Mailing Lists: https://lore.kernel.org/
* IRC: #kernelnewbies on irc.oftc.net
* Bugzilla: https://bugzilla.kernel.org/
* MAINTAINERS file: Lists subsystem maintainers and mailing lists
* Email Clients: Documentation/process/email-clients.rst