FAILED: patch "[PATCH] rust: kasan: KASAN+RUST requires clang" failed to apply to 6.18-stable tree

FAILED: patch "[PATCH] rust: kasan: KASAN+RUST requires clang" failed to apply to 6.18-stable tree

[gregkh]

The patch below does not apply to the 6.18-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.18.y
git checkout FETCH_HEAD
git cherry-pick -x 5b271543d0f08e9733d4732721e960e285f6448f
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026070939-ranged-unmapped-3ab9@gregkh' --subject-prefix 'PATCH 6.18.y' 'HEAD^..'

Possible dependencies:



thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 5b271543d0f08e9733d4732721e960e285f6448f Mon Sep 17 00:00:00 2001
From: Alice Ryhl <aliceryhl@google.com>
Date: Wed, 8 Apr 2026 08:32:16 +0000
Subject: [PATCH] rust: kasan: KASAN+RUST requires clang

Kernel KASAN involves passing various llvm/gcc specific arguments to
the C and Rust compiler. Since these arguments differ between llvm and
gcc, it's not safe to mix an llvm-based rustc with a gcc build when
kasan is enabled.

Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Cc: stable@vger.kernel.org
Fixes: e3117404b411 ("kbuild: rust: Enable KASAN support")
Link: https://patch.msgid.link/20260408-kasan-rust-sw-tags-v3-1-e07964d14363@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

diff --git a/init/Kconfig b/init/Kconfig
index 2937c4d308ae..826a7d768ca3 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -2198,6 +2198,7 @@ config RUST
 	depends on !DEBUG_INFO_BTF || (PAHOLE_HAS_LANG_EXCLUDE && !LTO)
 	depends on !CFI || HAVE_CFI_ICALL_NORMALIZE_INTEGERS_RUSTC
 	select CFI_ICALL_NORMALIZE_INTEGERS if CFI
+	depends on !KASAN || CC_IS_CLANG
 	depends on !KASAN_SW_TAGS
 	help
 	  Enables Rust support in the kernel.

[PATCH 6.18.y] rust: kasan: KASAN+RUST requires clang

[Miguel Ojeda]

From: Alice Ryhl <aliceryhl@google.com>

Kernel KASAN involves passing various llvm/gcc specific arguments to
the C and Rust compiler. Since these arguments differ between llvm and
gcc, it's not safe to mix an llvm-based rustc with a gcc build when
kasan is enabled.

Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Cc: stable@vger.kernel.org
Fixes: e3117404b411 ("kbuild: rust: Enable KASAN support")
Link: https://patch.msgid.link/20260408-kasan-rust-sw-tags-v3-1-e07964d14363@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
(cherry picked from commit 5b271543d0f08e9733d4732721e960e285f6448f)
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 init/Kconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/init/Kconfig b/init/Kconfig
index cab3ad28ca49..0c25e78e10f4 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -2096,6 +2096,7 @@ config RUST
 	depends on !CFI || HAVE_CFI_ICALL_NORMALIZE_INTEGERS_RUSTC
 	select CFI_ICALL_NORMALIZE_INTEGERS if CFI
 	depends on !CALL_PADDING || RUSTC_VERSION >= 108100
+	depends on !KASAN || CC_IS_CLANG
 	depends on !KASAN_SW_TAGS
 	depends on !(MITIGATION_RETHUNK && KASAN) || RUSTC_VERSION >= 108300
 	help
-- 
2.55.0

Re: [PATCH 6.18.y] rust: kasan: KASAN+RUST requires clang

[Sasha Levin]

On Thu, Jul 09, 2026 at 07:59:43PM +0200, Miguel Ojeda wrote:
> Kernel KASAN involves passing various llvm/gcc specific arguments to
> the C and Rust compiler. Since these arguments differ between llvm and
> gcc, it's not safe to mix an llvm-based rustc with a gcc build when
> kasan is enabled.

Queued for 6.18, thanks.

-- 
Thanks,
Sasha

Re: FAILED: patch "[PATCH] rust: kasan: KASAN+RUST requires clang" failed to apply to 6.18-stable tree

[Miguel Ojeda]

On Thu, Jul 9, 2026 at 7:36 PM <gregkh@linuxfoundation.org> wrote:
>
> The patch below does not apply to the 6.18-stable tree.
> If someone wants it applied there, or to any other stable or longterm
> tree, then please email the backport, including the original git commit
> id to <stable@vger.kernel.org>.
>
> To reproduce the conflict and resubmit, you may use the following commands:
>
> git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.18.y
> git checkout FETCH_HEAD
> git cherry-pick -x 5b271543d0f08e9733d4732721e960e285f6448f
> # <resolve conflicts, build, test, etc.>
> git commit -s
> git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026070939-ranged-unmapped-3ab9@gregkh' --subject-prefix 'PATCH 6.18.y' 'HEAD^..'

Done -- by the way, I assume Google uses

  72d33b8bfeac ("rust: kasan: add support for Software Tag-Based KASAN")

as well. It is not a bug fix, but if Google is using it and it works,
then it guess it could be added too.

Cheers,
Miguel