commit d6e5794b06c0fab74fe6e4fa55d508a5ceb14735 upstream. GCC seems to incorrectly fail to evaluate skb_ext_total_length() at compile time under certain conditions. The issue even occurs if all values in skb_ext_type_len[] are "0", ruling out the possibility of an actual overflow. As the patch has been in mainline since v6.6 without triggering the problem it seems to be a very uncommon occurrence. As the issue only occurs when -fno-tree-loop-im is specified as part of CFLAGS_GCOV, disable the BUILD_BUG_ON() only when building with coverage reporting enabled. Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202312171924.4FozI5FG-lkp@intel.com/ Suggested-by: Arnd Bergmann <arnd@arndb.de> Link: https://lore.kernel.org/lkml/487cfd35-fe68-416f-9bfd-6bb417f98304@app.fastmail.com/ Fixes: 5d21d0a65b57 ("net: generalize calculation of skb extensions length") Cc: <stable@vger.kernel.org> Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> Acked-by: Arnd Bergmann <arnd@arndb.de> Link: https://lore.kernel.org/r/20231218-net-skbuff-build-bug-v1-1-eefc2fb0a7d3@weissschuh.net Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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.
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