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
Pull landlock fixes from Mickaël Salaün:
"This fixes TCP handling, tests, documentation, non-audit elided code,
and minor cosmetic changes"
* tag 'landlock-6.19-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/mic/linux:
landlock: Clarify documentation for the IOCTL access right
selftests/landlock: Properly close a file descriptor
landlock: Improve the comment for domain_is_scoped
selftests/landlock: Use scoped_base_variants.h for ptrace_test
selftests/landlock: Fix missing semicolon
selftests/landlock: Fix typo in fs_test
landlock: Optimize stack usage when !CONFIG_AUDIT
landlock: Fix spelling
landlock: Clean up hook_ptrace_access_check()
landlock: Improve erratum documentation
landlock: Remove useless include
landlock: Fix wrong type usage
selftests/landlock: NULL-terminate unix pathname addresses
selftests/landlock: Remove invalid unix socket bind()
selftests/landlock: Add missing connect(minimal AF_UNSPEC) test
selftests/landlock: Fix TCP bind(AF_UNSPEC) test case
landlock: Fix TCP handling of short AF_UNSPEC addresses
landlock: Fix formatting
Pull cgroup fixes from Tejun Heo:
- Add Chen Ridong as cpuset reviewer
- Add SPDX license identifiers to cgroup files that were missing them
* tag 'cgroup-for-6.19-rc5-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
kernel: cgroup: Add LGPL-2.1 SPDX license ID to legacy_freezer.c
kernel: cgroup: Add SPDX-License-Identifier lines
MAINTAINERS: Add Chen Ridong as cpuset reviewer
Move the description of the LANDLOCK_ACCESS_FS_IOCTL_DEV access right
together with the file access rights.
This group of access rights applies to files (in this case device
files), and they can be added to file or directory inodes using
landlock_add_rule(2). The check for that works the same for all file
access rights, including LANDLOCK_ACCESS_FS_IOCTL_DEV.
Invoking ioctl(2) on directory FDs can not currently be restricted
with Landlock. Having it grouped separately in the documentation is a
remnant from earlier revisions of the LANDLOCK_ACCESS_FS_IOCTL_DEV
patch set.
Link: https://lore.kernel.org/all/20260108.Thaex5ruach2@digikod.net/
Signed-off-by: Günther Noack <gnoack3000@gmail.com>
Link: https://lore.kernel.org/r/20260111175203.6545-2-gnoack3000@gmail.com
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Pull ext4 fixes from Ted Ts'o:
- Fix an inconsistency in structure size on 32-bit platforms caused by
padding differences for the new EXT4_IOC_[GS]ET_TUNE_SB_PARAM ioctls
- Fix a buffer leak on the error path when dropping the refcount an
xattr value stored in an inode
- Fix missing locking on the error path for the file defragmentation
ioctl leading to a BUG
* tag 'ext4_for_linus-6.19-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
ext4: fix iloc.bh leak in ext4_xattr_inode_update_ref
ext4: add missing down_write_data_sem in mext_move_extent().
ext4: fix ext4_tune_sb_params padding
Add an appropriate SPDX-License-Identifier line to the file,
and remove the GNU boilerplate text.
Signed-off-by: Tim Bird <tim.bird@sony.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Add a missing close(srv_fd) call, and use EXPECT_EQ() to check the
result.
Signed-off-by: Günther Noack <gnoack3000@gmail.com>
Fixes: f83d51a5bdfe ("selftests/landlock: Check IOCTL restrictions for named UNIX domain sockets")
Link: https://lore.kernel.org/r/20260101134102.25938-2-gnoack3000@gmail.com
[mic: Use EXPECT_EQ() and update commit message]
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Pull dmaengine fixes from Vinod Koul:
"A bunch of driver fixes for:
- dma mask fix for mmp pdma driver
- Xilinx regmap max register, uninitialized addr_width fix
- device leak fix for bunch of drivers in the subsystem
- stm32 dmamux, TI crossbar driver fixes for device & of node leak
and route allocation cleanup
- Tegra use afer free fix
- Memory leak fix in Qualcomm gpi and omap-dma driver
- compatible fix for apple driver"
* tag 'dmaengine-fix-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/vkoul/dmaengine: (25 commits)
dmaengine: apple-admac: Add "apple,t8103-admac" compatible
dmaengine: omap-dma: fix dma_pool resource leak in error paths
dmaengine: qcom: gpi: Fix memory leak in gpi_peripheral_config()
dmaengine: sh: rz-dmac: Fix rz_dmac_terminate_all()
dmaengine: xilinx_dma: Fix uninitialized addr_width when "xlnx,addrwidth" property is missing
dmaengine: tegra-adma: Fix use-after-free
dmaengine: fsl-edma: Fix clk leak on alloc_chan_resources failure
dmaengine: mmp_pdma: Fix race condition in mmp_pdma_residue()
dmaengine: ti: k3-udma: fix device leak on udma lookup
dmaengine: ti: dma-crossbar: clean up dra7x route allocation error paths
dmaengine: ti: dma-crossbar: fix device leak on am335x route allocation
dmaengine: ti: dma-crossbar: fix device leak on dra7x route allocation
dmaengine: stm32: dmamux: clean up route allocation error labels
dmaengine: stm32: dmamux: fix OF node leak on route allocation failure
dmaengine: stm32: dmamux: fix device leak on route allocation
dmaengine: sh: rz-dmac: fix device leak on probe failure
dmaengine: lpc32xx-dmamux: fix device leak on route allocation
dmaengine: lpc18xx-dmamux: fix device leak on route allocation
dmaengine: idxd: fix device leaks on compat bind and unbind
dmaengine: dw: dmamux: fix OF node leak on route allocation failure
...
The error branch for ext4_xattr_inode_update_ref forget to release the
refcount for iloc.bh. Find this when review code.
Fixes: 57295e835408 ("ext4: guard against EA inode refcount underflow in xattr update")
Signed-off-by: Yang Erkun <yangerkun@huawei.com>
Reviewed-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
Link: https://patch.msgid.link/20251213055706.3417529-1-yangerkun@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Add GPL-2.0 SPDX license id lines to a few old
files, replacing the reference to the COPYING file.
The COPYING file at the time of creation of these files
(2007 and 2005) was GPL-v2.0, with an additional clause
indicating that only v2 applied.
Signed-off-by: Tim Bird <tim.bird@sony.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Currently it is not obvious what "scoped" mean, and the fact that the
function returns true when access should be denied is slightly surprising
and in need of documentation.
Cc: Tahera Fahimi <fahimitahera@gmail.com>
Signed-off-by: Tingmao Wang <m@maowtm.org>
Link: https://lore.kernel.org/r/06393bc18aee5bc278df5ef31c64a05b742ebc10.1766885035.git.m@maowtm.org
[mic: Fix formatting and improve consistency]
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Pull phy fixes from Vinod Koul:
"A bunch of driver fixes:
- Freescale typec orientation switch fix, clearing register fix,
assertion of phy reset during power on
- Qualcomm pcs register clear before using
- stm one off fix
- TI runtimepm error handling, regmap leak fixes
- Rockchip gadget mode disconnection and disruption fixes
- Tegra register level fix
- Broadcom pointer cast warning fix"
* tag 'phy-fixes-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/phy/linux-phy:
phy: freescale: imx8m-pcie: assert phy reset during power on
phy: rockchip: inno-usb2: Fix a double free bug in rockchip_usb2phy_probe()
phy: broadcom: ns-usb3: Fix Wvoid-pointer-to-enum-cast warning (again)
phy: tegra: xusb: Explicitly configure HS_DISCON_LEVEL to 0x7
phy: rockchip: inno-usb2: fix communication disruption in gadget mode
phy: rockchip: inno-usb2: fix disconnection in gadget mode
phy: ti: gmii-sel: fix regmap leak on probe failure
phy: sparx5-serdes: make it selectable for ARCH_LAN969X
phy: ti: da8xx-usb: Handle devm_pm_runtime_enable() errors
phy: stm32-usphyc: Fix off by one in probe()
phy: qcom-qusb2: Fix NULL pointer dereference on early suspend
phy: fsl-imx8mq-usb: Clear the PCS_TX_SWING_FULL field before using it
dt-bindings: phy: qcom,sc8280xp-qmp-pcie-phy: Update pcie phy bindings for qcs8300
phy: fsl-imx8mq-usb: fix typec orientation switch when built as module
After discussion with the devicetree maintainers we agreed to not extend
lists with the generic compatible "apple,admac" anymore [1]. Use
"apple,t8103-admac" as base compatible as it is the SoC the driver and
bindings were written for.
[1]: https://lore.kernel.org/asahi/12ab93b7-1fc2-4ce0-926e-c8141cfe81bf@kernel.org/
Fixes: b127315d9a78 ("dmaengine: apple-admac: Add Apple ADMAC driver")
Cc: stable@vger.kernel.org
Reviewed-by: Neal Gompa <neal@gompa.dev>
Signed-off-by: Janne Grunau <j@jannau.net>
Link: https://patch.msgid.link/20251231-apple-admac-t8103-base-compat-v1-1-ec24a3708f76@jannau.net
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Commit 962e8a01eab9 ("ext4: introduce mext_move_extent()") attempts to
call ext4_swap_extents() on the failure path to recover the swapped
extents, but fails to acquire locks for the two inode->i_data_sem,
triggering the BUG_ON statement in ext4_swap_extents().
This issue can be fixed by calling ext4_double_down_write_data_sem()
before ext4_swap_extents().
Signed-off-by: Julian Sun <sunjunchao@bytedance.com>
Reported-by: syzbot+4ea6bd8737669b423aae@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/69368649.a70a0220.38f243.0093.GAE@google.com/
Fixes: 962e8a01eab9 ("ext4: introduce mext_move_extent()")
Reviewed-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Link: https://patch.msgid.link/20251208123713.1971068-1-sunjunchao@bytedance.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Add Chen Ridong as a reviewer for the cpuset cgroup subsystem.
Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: Chen Ridong <chenridong@huaweicloud.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
ptrace_test.c currently contains a duplicated version of the
scoped_domains fixture variants. This patch removes that and make it use
the shared scoped_base_variants.h instead, like in
scoped_abstract_unix_test and scoped_signal_test.
This required renaming the hierarchy fixture to scoped_domains, but the
test is otherwise the same.
Cc: Tahera Fahimi <fahimitahera@gmail.com>
Signed-off-by: Tingmao Wang <m@maowtm.org>
Link: https://lore.kernel.org/r/48148f0134f95f819a25277486a875a6fd88ecf9.1766885035.git.m@maowtm.org
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Pull soundwire fix from Vinod Koul:
- Single off-by-one fix for allocating slave id
* tag 'soundwire-6.19-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vkoul/soundwire:
soundwire: bus: fix off-by-one when allocating slave IDs