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Filename Latest commit message Latest commit date
Qiu-ji Chen 249bcc912e dmaengine: mediatek: Fix a possible deadlock error in mtk_cqdma_tx_status()
[ Upstream commit 157ae5ffd76a2857ccb4b7ce40bc5a344ca00395 ]

Fix a potential deadlock bug. Observe that in the mtk-cqdma.c
file, functions like mtk_cqdma_issue_pending() and
mtk_cqdma_free_active_desc() properly acquire the pc lock before the vc
lock when handling pc and vc fields. However, mtk_cqdma_tx_status()
violates this order by first acquiring the vc lock before invoking
mtk_cqdma_find_active_desc(), which subsequently takes the pc lock. This
reversed locking sequence (vc → pc) contradicts the established
pc → vc order and creates deadlock risks.

Fix the issue by moving the vc lock acquisition code from
mtk_cqdma_find_active_desc() to mtk_cqdma_tx_status(). Ensure the pc lock
is acquired before the vc lock in the calling function to maintain correct
locking hierarchy. Note that since mtk_cqdma_find_active_desc() is a
static function with only one caller (mtk_cqdma_tx_status()), this
modification safely eliminates the deadlock possibility without affecting
other components.

This possible bug is found by an experimental static analysis tool
developed by our team. This tool analyzes the locking APIs to extract
function pairs that can be concurrently executed, and then analyzes the
instructions in the paired functions to identify possible concurrency bugs
including deadlocks, data races and atomicity violations.

Fixes: b1f01e48df ("dmaengine: mediatek: Add MediaTek Command-Queue DMA controller for MT6765 SoC")
Cc: stable@vger.kernel.org
Signed-off-by: Qiu-ji Chen <chenqiuji666@gmail.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20250508073634.3719-1-chenqiuji666@gmail.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-09-09 18:44:00 +02:00
arch KVM: x86: Take irqfds.lock when adding/deleting IRQ bypass producer 2025-09-09 18:44:00 +02:00
block block: fix 'kmem_cache of name 'bio-108' already exists' 2025-04-10 14:29:37 +02:00
certs
crypto crypto: algif_hash - fix double free in hash_accept 2025-06-04 14:32:35 +02:00
Documentation Documentation: ACPI: Fix parent device references 2025-08-28 16:21:23 +02:00
drivers dmaengine: mediatek: Fix a possible deadlock error in mtk_cqdma_tx_status() 2025-09-09 18:44:00 +02:00
fs efivarfs: Fix slab-out-of-bounds in efivarfs_d_compare 2025-09-04 14:05:55 +02:00
include atm: atmtcp: Prevent arbitrary write in atmtcp_recv_control(). 2025-09-04 14:05:54 +02:00
init bpfilter: match bit size of bpfilter_umh to that of the kernel 2025-07-17 18:24:51 +02:00
ipc ipc: fix to protect IPCS lookups using RCU 2025-06-27 11:02:52 +01:00
kernel cpufreq/sched: Explicitly synchronize limits_changed flag handling 2025-09-09 18:44:00 +02:00
lib lib: test_objagg: Set error message in check_expect_hints_stats() 2025-07-17 18:24:56 +02:00
LICENSES
mm mm/slub: avoid accessing metadata when pointer is invalid in object_err() 2025-09-09 18:43:59 +02:00
net batman-adv: fix OOB read/write in network-coding decode 2025-09-09 18:43:59 +02:00
samples samples: mei: Fix building on musl libc 2025-08-28 16:21:19 +02:00
scripts kbuild: Add KBUILD_CPPFLAGS to as-option invocation 2025-08-28 16:21:33 +02:00
security securityfs: don't pin dentries twice, once is enough... 2025-08-28 16:21:24 +02:00
sound ALSA: hda/realtek - Add new HP ZBook laptop with micmute led fixup 2025-09-09 18:44:00 +02:00
tools act_mirred: use the backlog for nested calls to mirred ingress 2025-08-28 16:21:36 +02:00
usr kbuild: hdrcheck: fix cross build with clang 2025-07-17 18:24:51 +02:00
virt KVM: arm64: Ignore PMCNTENSET_EL0 while checking for overflow status 2024-12-19 18:05:04 +01:00
.clang-format
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore Remove *.orig pattern from .gitignore 2024-11-08 16:20:33 +01:00
.mailmap
COPYING
CREDITS
Kbuild
Kconfig
MAINTAINERS platform: Add Surface platform directory 2025-06-27 11:02:56 +01:00
Makefile Linux 5.4.298 2025-09-04 14:05:56 +02:00
README

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

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.