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
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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
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
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>
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
After U-Boot initializes PCIe with "pcie enum", Linux fails to detect
an NVMe disk on some boot cycles with:
phy phy-32f00000.pcie-phy.0: phy poweron failed --> -110
Discussion with NXP identified that the iMX8MP PCIe PHY PLL may fail to
lock when re-initialized without a reset cycle [1].
The issue reproduces on 7% of tested hardware platforms, with a 30-40%
failure rate per affected device across boot cycles.
Insert a reset cycle in the power-on routine to ensure the PHY is
initialized from a known state.
[1] https://community.nxp.com/t5/i-MX-Processors/iMX8MP-PCIe-initialization-in-U-Boot/m-p/2248437#M242401
Signed-off-by: Rafael Beims <rafael.beims@toradex.com>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20251223150254.1075221-1-rafael@beims.me
Signed-off-by: Vinod Koul <vkoul@kernel.org>
The dma_pool created by dma_pool_create() is not destroyed when
dma_async_device_register() or of_dma_controller_register() fails,
causing a resource leak in the probe error paths.
Add dma_pool_destroy() in both error paths to properly release the
allocated dma_pool resource.
Fixes: 7bedaa553760 ("dmaengine: add OMAP DMA engine driver")
Signed-off-by: Haotian Zhang <vulab@iscas.ac.cn>
Link: https://patch.msgid.link/20251103073018.643-1-vulab@iscas.ac.cn
Signed-off-by: Vinod Koul <vkoul@kernel.org>
The padding at the end of struct ext4_tune_sb_params is architecture
specific and in particular is different between x86-32 and x86-64,
since the __u64 member only enforces struct alignment on the latter.
This shows up as a new warning when test-building the headers with
-Wpadded:
include/linux/ext4.h:144:1: error: padding struct size to alignment boundary with 4 bytes [-Werror=padded]
All members inside the structure are naturally aligned, so the only
difference here is the amount of padding at the end. Make the padding
explicit, to have a consistent sizeof(struct ext4_tune_sb_params) of
232 on all architectures and avoid adding compat ioctl handling for
EXT4_IOC_GET_TUNE_SB_PARAM/EXT4_IOC_SET_TUNE_SB_PARAM.
This is an ABI break on x86-32 but hopefully this can go into 6.18.y early
enough as a fixup so no actual users will be affected. Alternatively, the
kernel could handle the ioctl commands for both sizes (232 and 228 bytes)
on all architectures.
Fixes: 04a91570ac67 ("ext4: implemet new ioctls to set and get superblock parameters")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20251204101914.1037148-1-arnd@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Pull USB fixes from Greg KH:
"Here are some small USB fixes and new device ids for 6.19-rc6
Included in here are:
- new usb-serial device ids
- dwc3-apple driver fixes to get things working properly on that
hardware platform
- ohci/uhci platfrom driver module soft-deps with ehci to remove a
runtime warning that sometimes shows up on some platforms.
- quirk for broken devices that can not handle reading the BOS
descriptor from them without going crazy.
- usb-serial driver fixes
- xhci driver fixes
- usb gadget driver fixes
All of these except for the last xhci fix has been in linux-next for a
while. The xhci fix has been reported by others to solve the issue for
them, so should be ok"
* tag 'usb-6.19-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
xhci: sideband: don't dereference freed ring when removing sideband endpoint
usb: gadget: uvc: retry vb2_reqbufs() with vb_vmalloc_memops if use_sg fail
usb: gadget: uvc: return error from uvcg_queue_init()
usb: gadget: uvc: fix interval_duration calculation
usb: gadget: uvc: fix req_payload_size calculation
usb: dwc3: apple: Ignore USB role switches to the active role
usb: host: xhci-tegra: Use platform_get_irq_optional() for wake IRQs
USB: OHCI/UHCI: Add soft dependencies on ehci_platform
usb: dwc3: apple: Set USB2 PHY mode before dwc3 init
USB: serial: f81232: fix incomplete serial port generation
USB: serial: ftdi_sio: add support for PICAXE AXE027 cable
USB: serial: option: add Telit LE910 MBIM composition
usb: core: add USB_QUIRK_NO_BOS for devices that hang on BOS descriptor
dt-bindings: usb: qcom,dwc3: Correct MSM8994 interrupts
dt-bindings: usb: qcom,dwc3: Correct IPQ5018 interrupts
tcpm: allow looking for role_sw device in the main node
usb: dwc3: Check for USB4 IP_NAME
ida_alloc_max() interprets its max argument as inclusive.
Using SDW_FW_MAX_DEVICES(16) therefore allows an ID of 16 to be
allocated, but the IRQ domain created for the bus is sized for IDs
0-15. If 16 is returned, irq_create_mapping() fails and the driver
ends up with an invalid IRQ mapping.
Limit the allocation to 0-15 by passing SDW_FW_MAX_DEVICES - 1.
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/r/202512240450.hlDH3nCs-lkp@intel.com/
Fixes: aab12022b076 ("soundwire: bus: Add internal slave ID and use for IRQs")
Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
Reviewed-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Link: https://patch.msgid.link/20260110201959.2523024-1-harshit.m.mogalapalli@oracle.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
The for_each_available_child_of_node() calls of_node_put() to
release child_np in each success loop. After breaking from the
loop with the child_np has been released, the code will jump to
the put_child label and will call the of_node_put() again if the
devm_request_threaded_irq() fails. These cause a double free bug.
Fix by returning directly to avoid the duplicate of_node_put().
Fixes: ed2b5a8e6b98 ("phy: phy-rockchip-inno-usb2: support muxed interrupts")
Cc: stable@vger.kernel.org
Signed-off-by: Wentao Liang <vulab@iscas.ac.cn>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patch.msgid.link/20260109154626.2452034-1-vulab@iscas.ac.cn
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Fix a memory leak in gpi_peripheral_config() where the original memory
pointed to by gchan->config could be lost if krealloc() fails.
The issue occurs when:
1. gchan->config points to previously allocated memory
2. krealloc() fails and returns NULL
3. The function directly assigns NULL to gchan->config, losing the
reference to the original memory
4. The original memory becomes unreachable and cannot be freed
Fix this by using a temporary variable to hold the krealloc() result
and only updating gchan->config when the allocation succeeds.
Found via static analysis and code review.
Fixes: 5d0c3533a19f ("dmaengine: qcom: Add GPI dma driver")
Cc: stable@vger.kernel.org
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Reviewed-by: Bjorn Andersson <andersson@kernel.org>
Link: https://patch.msgid.link/20251029123421.91973-1-linmq006@gmail.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Pull i2c fixes from Wolfram Sang:
- riic, imx-lpi2c: suspend/resume fixes
- qcom-geni: DMA handling fix
- iproc: correct DT binding description
* tag 'i2c-for-6.19-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
i2c: imx-lpi2c: change to PIO mode in system-wide suspend/resume progress
i2c: qcom-geni: make sure I2C hub controllers can't use SE DMA
i2c: riic: Move suspend handling to NOIRQ phase
dt-bindings: i2c: brcm,iproc-i2c: Allow 2 reg entries for brcm,iproc-nic-i2c