No description
  • C 96.8%
  • Assembly 0.9%
  • Rust 0.7%
  • Shell 0.6%
  • Python 0.5%
  • Other 0.3%
Find a file
Gui-Dong Han 83e2ba8971 hwmon: (ftsteutates) Fix TOCTOU race in fts_read()
commit 14c9ede9ca upstream.

In the fts_read() function, when handling hwmon_pwm_auto_channels_temp,
the code accesses the shared variable data->fan_source[channel] twice
without holding any locks. It is first checked against
FTS_FAN_SOURCE_INVALID, and if the check passes, it is read again
when used as an argument to the BIT() macro.

This creates a Time-of-Check to Time-of-Use (TOCTOU) race condition.
Another thread executing fts_update_device() can modify the value of
data->fan_source[channel] between the check and its use. If the value
is changed to FTS_FAN_SOURCE_INVALID (0xff) during this window, the
BIT() macro will be called with a large shift value (BIT(255)).
A bit shift by a value greater than or equal to the type width is
undefined behavior and can lead to a crash or incorrect values being
returned to userspace.

Fix this by reading data->fan_source[channel] into a local variable
once, eliminating the race condition. Additionally, add a bounds check
to ensure the value is less than BITS_PER_LONG before passing it to
the BIT() macro, making the code more robust against undefined behavior.

This possible bug was found by an experimental static analysis tool
developed by our team.

Fixes: 1c5759d8ce ("hwmon: (ftsteutates) Replace fanX_source with pwmX_auto_channels_temp")
Cc: stable@vger.kernel.org
Signed-off-by: Gui-Dong Han <hanguidong02@gmail.com>
Link: https://lore.kernel.org/r/20250606071640.501262-1-hanguidong02@gmail.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
History 2025-06-27 11:11:21 +01:00
arch ARM: omap: pmic-cpcap: do not mess around without CPCAP or OMAP4 2025-06-27 11:11:19 +01:00
block block: Clear BIO_EMULATES_ZONE_APPEND flag on BIO completion 2025-06-27 11:11:19 +01:00
certs sign-file,extract-cert: use pkcs11 provider for OPENSSL MAJOR >= 3 2024-09-20 19:52:48 +03:00
crypto crypto: api - Redo lookup on EEXIST 2025-06-19 15:31:30 +02:00
Documentation regulator: dt-bindings: mt6357: Drop fixed compatible requirement 2025-06-19 15:32:37 +02:00
drivers hwmon: (ftsteutates) Fix TOCTOU race in fts_read() 2025-06-27 11:11:21 +01:00
fs f2fs: fix to do sanity check on sit_bitmap_size 2025-06-27 11:11:21 +01:00
include bus: firewall: Fix missing static inline annotations for stubs 2025-06-27 11:11:19 +01:00
init rust: clean Rust 1.88.0's unnecessary_transmutes lint 2025-05-18 08:24:51 +02:00
io_uring io_uring/kbuf: account ring io_buffer_list memory 2025-06-27 11:11:14 +01:00
ipc ipc: fix memleak if msg_init_ns failed in create_ipc_ns 2024-12-05 14:03:02 +01:00
kernel cgroup,freezer: fix incomplete freezing when attaching tasks 2025-06-27 11:11:19 +01:00
lib iov_iter: use iov_offset for length calculation in iov_iter_aligned_bvec 2025-06-19 15:32:21 +02:00
LICENSES LICENSES: add 0BSD license text 2024-09-01 20:43:24 -07:00
mm page_pool: Move pp_magic check into helper functions 2025-06-19 15:31:42 +02:00
net svcrdma: Unregister the device if svc_rdma_accept() fails 2025-06-27 11:11:16 +01:00
rust rust: alloc: add missing invariant in Vec::set_len() 2025-06-19 15:32:09 +02:00
samples samples/bpf: Fix compilation failure for samples/bpf on LoongArch Fedora 2025-05-29 11:02:01 +02:00
scripts randstruct: gcc-plugin: Fix attribute addition 2025-06-19 15:32:04 +02:00
security smack: Revert "smackfs: Added check catlen" 2025-05-29 11:02:48 +02:00
sound ASoC: codecs: wcd937x: Drop unused buck_supply 2025-06-27 11:11:19 +01:00
tools tools/resolve_btfids: Fix build when cross compiling kernel with clang. 2025-06-19 15:32:33 +02:00
usr kbuild: hdrcheck: fix cross build with clang 2025-03-13 13:02:18 +01:00
virt KVM: Add member to struct kvm_gfn_range to indicate private/shared 2025-05-22 14:29:36 +02:00
.clang-format clang-format: Update with v6.11-rc1's for_each macro list 2024-08-02 13:20:31 +02:00
.clippy.toml rust: clean Rust 1.88.0's warning about clippy::disallowed_macros configuration 2025-05-18 08:24:51 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.editorconfig .editorconfig: remove trim_trailing_whitespace option 2024-06-13 16:47:52 +02:00
.get_maintainer.ignore Add Jeff Kirsher to .get_maintainer.ignore 2024-03-08 11:36:54 +00:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore rust: introduce .clippy.toml 2025-03-13 13:01:42 +01:00
.mailmap mailmap: add entry for Thorsten Blum 2024-11-07 14:14:59 -08:00
.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 MAINTAINERS: Remove self from DSA entry 2024-11-03 12:52:38 -08:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS MAINTAINERS: Update Alexey Makhalov's email address 2025-05-22 14:29:46 +02:00
Makefile Linux 6.12.34 2025-06-19 15:32:38 +02:00
README README: Fix spelling 2024-03-18 03:36:32 -06:00

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 reStructuredText 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.