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da1983355c
When booting a CONFIG_FORTIFY_SOURCE=y kernel compiled with a toolchain
that supports __counted_by() (such as clang-18 and newer), there is a
panic on boot:
[ 2.913770] memcpy: detected buffer overflow: 72 byte write of buffer size 0
[ 2.920834] WARNING: CPU: 2 PID: 1 at lib/string_helpers.c:1027 __fortify_report+0x5c/0x74
...
[ 3.039208] Call trace:
[ 3.041643] __fortify_report+0x5c/0x74
[ 3.045469] __fortify_panic+0x18/0x20
[ 3.049209] thermal_zone_device_register_with_trips+0x4c8/0x4f8
This panic occurs because trips is counted by num_trips but num_trips is
assigned after the call to memcpy(), so the fortify checks think the
buffer size is zero because tz was allocated with kzalloc().
Move the num_trips assignment before the memcpy() to resolve the panic
and ensure that the fortify checks work properly.
Fixes: 9b0a627586 ("thermal: core: Store zone trips table in struct thermal_zone_device")
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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.