From: Sami Tolvanen <samitolvanen@google.com>
To: Kees Cook <keescook@chromium.org>
Cc: Nathan Chancellor <nathan@kernel.org>,
Nick Desaulniers <ndesaulniers@google.com>,
Masahiro Yamada <masahiroy@kernel.org>,
Will Deacon <will@kernel.org>, Jessica Yu <jeyu@kernel.org>,
Arnd Bergmann <arnd@arndb.de>, Tejun Heo <tj@kernel.org>,
bpf@vger.kernel.org, linux-hardening@vger.kernel.org,
linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
linux-kbuild@vger.kernel.org, linux-pci@vger.kernel.org,
linux-kernel@vger.kernel.org,
Sami Tolvanen <samitolvanen@google.com>
Subject: [PATCH 04/17] module: cfi: ensure __cfi_check alignment
Date: Thu, 11 Mar 2021 16:49:06 -0800 [thread overview]
Message-ID: <20210312004919.669614-5-samitolvanen@google.com> (raw)
In-Reply-To: <20210312004919.669614-1-samitolvanen@google.com>
CONFIG_CFI_CLANG_SHADOW assumes the __cfi_check() function is page
aligned and at the beginning of the .text section. While Clang would
normally align the function correctly, it fails to do so for modules
with no executable code.
This change ensures the correct __cfi_check() location and
alignment. It also discards the .eh_frame section, which Clang can
generate with certain sanitizers, such as CFI.
Link: https://bugs.llvm.org/show_bug.cgi?id=46293
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
---
scripts/module.lds.S | 14 +++++++++++++-
1 file changed, 13 insertions(+), 1 deletion(-)
diff --git a/scripts/module.lds.S b/scripts/module.lds.S
index 168cd27e6122..552ddb084f76 100644
--- a/scripts/module.lds.S
+++ b/scripts/module.lds.S
@@ -3,10 +3,13 @@
* Archs are free to supply their own linker scripts. ld will
* combine them automatically.
*/
+#include <asm/page.h>
+
SECTIONS {
/DISCARD/ : {
*(.discard)
*(.discard.*)
+ *(.eh_frame)
}
__ksymtab 0 : { *(SORT(___ksymtab+*)) }
@@ -40,7 +43,16 @@ SECTIONS {
*(.rodata..L*)
}
- .text : { *(.text .text.[0-9a-zA-Z_]*) }
+#ifdef CONFIG_CFI_CLANG
+ /*
+ * With CFI_CLANG, ensure __cfi_check is at the beginning of the
+ * .text section, and that the section is aligned to page size.
+ */
+ .text : ALIGN(PAGE_SIZE) {
+ *(.text.__cfi_check)
+ *(.text .text.[0-9a-zA-Z_]* .text..L.cfi*)
+ }
+#endif
}
/* bring in arch-specific sections */
--
2.31.0.rc2.261.g7f71774620-goog
next prev parent reply other threads:[~2021-03-12 0:50 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-12 0:49 [PATCH 00/17] Add support for Clang CFI Sami Tolvanen
2021-03-12 0:49 ` [PATCH 01/17] add " Sami Tolvanen
2021-03-12 2:39 ` Kees Cook
2021-03-12 0:49 ` [PATCH 02/17] cfi: add __cficanonical Sami Tolvanen
2021-03-12 2:40 ` Kees Cook
2021-03-12 20:28 ` Bjorn Helgaas
2021-03-12 0:49 ` [PATCH 03/17] mm: add generic __va_function and __pa_function macros Sami Tolvanen
2021-03-12 2:40 ` Kees Cook
2021-03-12 0:49 ` Sami Tolvanen [this message]
2021-03-12 2:39 ` [PATCH 04/17] module: cfi: ensure __cfi_check alignment Kees Cook
2021-03-16 20:03 ` Sami Tolvanen
2021-03-12 0:49 ` [PATCH 05/17] workqueue: cfi: disable callback pointer check with modules Sami Tolvanen
2021-03-12 2:43 ` Kees Cook
2021-03-12 0:49 ` [PATCH 06/17] kthread: " Sami Tolvanen
2021-03-12 2:43 ` Kees Cook
2021-03-12 6:13 ` Christoph Hellwig
2021-03-17 16:05 ` Sami Tolvanen
2021-03-12 0:49 ` [PATCH 07/17] kallsyms: cfi: strip hashes from static functions Sami Tolvanen
2021-03-12 2:45 ` Kees Cook
2021-03-16 20:33 ` Sami Tolvanen
2021-03-12 0:49 ` [PATCH 08/17] bpf: disable CFI in dispatcher functions Sami Tolvanen
2021-03-12 2:45 ` Kees Cook
2021-03-12 0:49 ` [PATCH 09/17] lib/list_sort: fix function type mismatches Sami Tolvanen
2021-03-12 2:45 ` Kees Cook
2021-03-12 0:49 ` [PATCH 10/17] lkdtm: use __va_function Sami Tolvanen
2021-03-12 2:45 ` Kees Cook
2021-03-12 0:49 ` [PATCH 11/17] psci: use __pa_function for cpu_resume Sami Tolvanen
2021-03-12 2:45 ` Kees Cook
2021-03-12 0:49 ` [PATCH 12/17] arm64: implement __va_function Sami Tolvanen
2021-03-12 2:46 ` Kees Cook
2021-03-12 0:49 ` [PATCH 13/17] arm64: use __pa_function Sami Tolvanen
2021-03-12 2:46 ` Kees Cook
2021-03-12 0:49 ` [PATCH 14/17] arm64: add __nocfi to functions that jump to a physical address Sami Tolvanen
2021-03-12 2:47 ` Kees Cook
2021-03-12 0:49 ` [PATCH 15/17] arm64: add __nocfi to __apply_alternatives Sami Tolvanen
2021-03-12 2:50 ` Kees Cook
2021-03-12 0:49 ` [PATCH 16/17] KVM: arm64: Disable CFI for nVHE Sami Tolvanen
2021-03-12 2:50 ` Kees Cook
2021-03-12 0:49 ` [PATCH 17/17] arm64: allow CONFIG_CFI_CLANG to be selected Sami Tolvanen
2021-03-12 2:51 ` Kees Cook
2021-03-16 20:44 ` Sami Tolvanen
2021-03-16 23:02 ` Kees Cook
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