This is a note to let you know that I've just added the patch titled
cfi: Fix CFI failure with KASAN
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
cfi-fix-cfi-failure-with-kasan.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 827e3664f20241d04bc912178835e48fb8d2f30f
Author: Sami Tolvanen <samitolvanen@xxxxxxxxxx>
Date: Thu Dec 22 22:57:47 2022 +0000
cfi: Fix CFI failure with KASAN
[ Upstream commit cf8016408d880afe9c5dc495af40dc2932874e77 ]
When CFI_CLANG and KASAN are both enabled, LLVM doesn't generate a
CFI type hash for asan.module_ctor functions in translation units
where CFI is disabled, which leads to a CFI failure during boot when
do_ctors calls the affected constructors:
CFI failure at do_basic_setup+0x64/0x90 (target:
asan.module_ctor+0x0/0x28; expected type: 0xa540670c)
Specifically, this happens because CFI is disabled for
kernel/cfi.c. There's no reason to keep CFI disabled here anymore, so
fix the failure by not filtering out CC_FLAGS_CFI for the file.
Note that https://reviews.llvm.org/rG3b14862f0a96 fixed the issue
where LLVM didn't emit CFI type hashes for any sanitizer constructors,
but now type hashes are emitted correctly for TUs that use CFI.
Link: https://github.com/ClangBuiltLinux/linux/issues/1742
Fixes: 89245600941e ("cfi: Switch to -fsanitize=kcfi")
Reported-by: Mark Rutland <mark.rutland@xxxxxxx>
Signed-off-by: Sami Tolvanen <samitolvanen@xxxxxxxxxx>
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20221222225747.3538676-1-samitolvanen@xxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/kernel/Makefile b/kernel/Makefile
index d754e0be1176..ebc692242b68 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -41,9 +41,6 @@ UBSAN_SANITIZE_kcov.o := n
KMSAN_SANITIZE_kcov.o := n
CFLAGS_kcov.o := $(call cc-option, -fno-conserve-stack) -fno-stack-protector
-# Don't instrument error handlers
-CFLAGS_REMOVE_cfi.o := $(CC_FLAGS_CFI)
-
obj-y += sched/
obj-y += locking/
obj-y += power/
