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author | Kees Cook <keescook@chromium.org> | 2021-05-12 21:51:10 -0700 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-11-21 13:46:35 +0100 |
commit | eaafc590053b314d4907017044ba2e739893c17c (patch) | |
tree | 710f07572297f67f2537a5d49463ba1fee81ef33 | |
parent | f884bb85b8d877d4e0c670403754813a7901705b (diff) | |
download | linux-stable-eaafc590053b314d4907017044ba2e739893c17c.tar.gz linux-stable-eaafc590053b314d4907017044ba2e739893c17c.tar.bz2 linux-stable-eaafc590053b314d4907017044ba2e739893c17c.zip |
fortify: Explicitly disable Clang support
commit a52f8a59aef46b59753e583bf4b28fccb069ce64 upstream.
Clang has never correctly compiled the FORTIFY_SOURCE defenses due to
a couple bugs:
Eliding inlines with matching __builtin_* names
https://bugs.llvm.org/show_bug.cgi?id=50322
Incorrect __builtin_constant_p() of some globals
https://bugs.llvm.org/show_bug.cgi?id=41459
In the process of making improvements to the FORTIFY_SOURCE defenses, the
first (silent) bug (coincidentally) becomes worked around, but exposes
the latter which breaks the build. As such, Clang must not be used with
CONFIG_FORTIFY_SOURCE until at least latter bug is fixed (in Clang 13),
and the fortify routines have been rearranged.
Update the Kconfig to reflect the reality of the current situation.
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://lore.kernel.org/lkml/CAKwvOd=A+ueGV2ihdy5GtgR2fQbcXjjAtVxv3=cPjffpebZB7A@mail.gmail.com
Cc: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r-- | security/Kconfig | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/security/Kconfig b/security/Kconfig index 7561f6f99f1d..0548db16c49d 100644 --- a/security/Kconfig +++ b/security/Kconfig @@ -191,6 +191,9 @@ config HARDENED_USERCOPY_PAGESPAN config FORTIFY_SOURCE bool "Harden common str/mem functions against buffer overflows" depends on ARCH_HAS_FORTIFY_SOURCE + # https://bugs.llvm.org/show_bug.cgi?id=50322 + # https://bugs.llvm.org/show_bug.cgi?id=41459 + depends on !CC_IS_CLANG help Detect overflows of buffers in common string and memory functions where the compiler can determine and validate the buffer sizes. |