Add `-Zsanitize=kernel-hwaddress` by Darksonn · Pull Request #153049 · rust-lang/rust

Darksonn · 2026-02-24T14:39:37Z

The Linux kernel has a config option called CONFIG_KASAN_SW_TAGS that enables -fsanitize=kernel-hwaddress. This is not supported by Rust.

One slightly awkward detail is that #[sanitize(address = "off")] applies to both -Zsanitize=address and -Zsanitize=kernel-address. Probably it was done this way because both are the same LLVM pass. I replicated this logic here for hwaddress, but it might be undesirable.

Note that #[sanitize(kernel_hwaddress = "off")] could be supported as an annotation on statics, but since it's also missing for #[sanitize(hwaddress = "off")], I did not add it.

MCP: rust-lang/compiler-team#975
Tracking issue: #154171

cc @rcvalle @maurer @ojeda

Darksonn · 2026-03-07T12:42:12Z

compiler/rustc_codegen_llvm/src/llvm_util.rs

+        // KHWASAN: In LLVM versions prior to 21.1.0, the HWAddressSanitizer pass incorrectly
+        // ignores the pass-specific `CompileKernel` flag and only looks at the global command-line
+        // flag `-hwasan-kernel`. To work around this, pass `-hwasan-kernel` on the relevant LLVM
+        // versions.
+        //
+        // Fixed by: [HWASan][bugfix] Fix kernel check in ShadowMapping::init (#142226).
+        if sess.sanitizers().contains(SanitizerSet::KERNELHWADDRESS) && get_version() < (21, 1, 0) {
+            add("-hwasan-kernel", false);
+        }


@fmayer Is this reasonable a reasonable fix for rustc to work around the lack of llvm/llvm-project#142226? Or do you think I should pass this on all versions? Thanks!

rustbot · 2026-03-07T16:19:25Z

Some changes occurred in cfg and check-cfg configuration

cc @Urgau

Some changes occurred in tests/ui/sanitizer

cc @rcvalle

Some changes occurred in src/tools/compiletest

cc @jieyouxu

Some changes occurred in tests/codegen-llvm/sanitizer

cc @rcvalle

Some changes occurred in compiler/rustc_attr_parsing

cc @jdonszelmann, @JonathanBrouwer

rustbot · 2026-03-07T16:19:27Z

r? @chenyukang

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rcvalle · 2026-03-14T03:41:57Z

cc @1c3t3a @jakos-sec

rustbot · 2026-03-17T20:24:20Z

This PR was rebased onto a different main commit. Here's a range-diff highlighting what actually changed.

Rebasing is a normal part of keeping PRs up to date, so no action is needed—this note is just to help reviewers.

Fix minor kasan bugs Fixes a few minor bugs discovered during rust-lang/rust#153049.

Darksonn · 2026-03-18T06:55:47Z

r? compiler

fmease

Thanks! Two notes

View changes since this review

fmease · 2026-03-24T14:37:58Z

compiler/rustc_codegen_ssa/src/back/link.rs

    if sanitizer.contains(SanitizerSet::LEAK)
        && !sanitizer.contains(SanitizerSet::ADDRESS)
        && !sanitizer.contains(SanitizerSet::HWADDRESS)
+        && !sanitizer.contains(SanitizerSet::KERNELHWADDRESS)


Suggested change

&& !sanitizer.contains(SanitizerSet::KERNELHWADDRESS)

I don't think this is necessary since -Zsanitizer=leak,kernel-hwaddress gets rejected on grounds of being incompatible. That's likely also why KERNELADDRESS isn't listed here, -Zsanitizer=leak,kernel-address is an error, too.

See also https://github.com/llvm/llvm-project/blob/4fcc3d7f4ced4f911883f4427907d2a7d66d951f/clang/include/clang/Driver/SanitizerArgs.h#L105-L109.

fmease · 2026-03-24T15:08:45Z

compiler/rustc_attr_parsing/src/attributes/codegen_attrs.rs

(commenting on an arbitrary file)

Could you add a section for KernelHwAddressSanitizer to the Unstable Book (in src/doc/unstable-book/, cc https://doc.rust-lang.org/unstable-book/compiler-flags/sanitizer.html). A stub would be sufficient.

fmease · 2026-03-24T16:52:49Z

@bors try jobs=test-various,aarch64-gnu

Add `-Zsanitize=kernel-hwaddress` try-job: test-various try-job: aarch64-gnu

rustbot · 2026-03-24T17:46:43Z

Some changes occurred in src/doc/unstable-book/src/compiler-flags/sanitizer.md

cc @rust-lang/project-exploit-mitigations, @rcvalle

compiletest directives have been modified. Please add or update docs for the
new or modified directive in src/doc/rustc-dev-guide/.

These commits modify compiler targets.
(See the Target Tier Policy.)

Darksonn · 2026-03-24T17:47:00Z

@rustbot ready

rust-bors · 2026-03-24T19:11:23Z

☀️ Try build successful (CI)
Build commit: 6ca6a86 (6ca6a8630bd864d73f6922a0a95b501387897d05, parent: 0312931d8c0ba1a28268a12c06202b68cbc65f76)

fmease · 2026-03-24T22:29:20Z

Thanks! @bors r+

rust-bors · 2026-03-24T22:29:23Z

📌 Commit 4d86840 has been approved by fmease

It is now in the queue for this repository.

@rcvalle

Add `-Zsanitize=kernel-hwaddress` The Linux kernel has a config option called `CONFIG_KASAN_SW_TAGS` that enables `-fsanitize=kernel-hwaddress`. This is not supported by Rust. One slightly awkward detail is that `#[sanitize(address = "off")]` applies to both `-Zsanitize=address` and `-Zsanitize=kernel-address`. Probably it was done this way because both are the same LLVM pass. I replicated this logic here for hwaddress, but it might be undesirable. Note that `#[sanitize(kernel_hwaddress = "off")]` could be supported as an annotation on statics, but since it's also missing for `#[sanitize(hwaddress = "off")]`, I did not add it. MCP: rust-lang/compiler-team#975 Tracking issue: rust-lang#154171 cc @rcvalle @maurer @ojeda

Rollup of 6 pull requests Successful merges: - #154004 (`Alignment`: move from `ptr` to `mem` and rename `as_nonzero` to `as_nonzero_usize`) - #153049 (Add `-Zsanitize=kernel-hwaddress`) - #154269 (miri recursive validation: only check one layer deep) - #154112 (some `tests/ui/macros` cleanup) - #154131 (begin `tests/ui/structs-enums` cleanup) - #154233 (Move ui/issues tests to relevant subdirectories)

@rcvalle

Add `-Zsanitize=kernel-hwaddress` The Linux kernel has a config option called `CONFIG_KASAN_SW_TAGS` that enables `-fsanitize=kernel-hwaddress`. This is not supported by Rust. One slightly awkward detail is that `#[sanitize(address = "off")]` applies to both `-Zsanitize=address` and `-Zsanitize=kernel-address`. Probably it was done this way because both are the same LLVM pass. I replicated this logic here for hwaddress, but it might be undesirable. Note that `#[sanitize(kernel_hwaddress = "off")]` could be supported as an annotation on statics, but since it's also missing for `#[sanitize(hwaddress = "off")]`, I did not add it. MCP: rust-lang/compiler-team#975 Tracking issue: rust-lang#154171 cc @rcvalle @maurer @ojeda

Rollup of 5 pull requests Successful merges: - #153049 (Add `-Zsanitize=kernel-hwaddress`) - #154269 (miri recursive validation: only check one layer deep) - #154112 (some `tests/ui/macros` cleanup) - #154131 (begin `tests/ui/structs-enums` cleanup) - #154233 (Move ui/issues tests to relevant subdirectories)

Darksonn added the A-sanitizers Area: Sanitizers for correctness and code quality label Feb 24, 2026

Darksonn force-pushed the kasan-sw-tags branch from 1191bc5 to 07c2a2a Compare February 24, 2026 14:52

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ojeda mentioned this pull request Feb 24, 2026

rustc wanted features & bugfixes Rust-for-Linux/linux#355

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Darksonn force-pushed the kasan-sw-tags branch from 941168b to 83e2f79 Compare March 7, 2026 14:24

Darksonn marked this pull request as ready for review March 7, 2026 16:19

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Add -Zsanitizer=kernel-hwaddress rust-lang/compiler-team#975

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github-actions bot pushed a commit to rust-lang/rustc-dev-guide that referenced this pull request Mar 18, 2026

Rollup merge of #153965 - Darksonn:kasan-minor-bugs, r=JonathanBrouwer

07405d2

Fix minor kasan bugs Fixes a few minor bugs discovered during rust-lang/rust#153049.

github-actions bot pushed a commit to rust-lang/miri that referenced this pull request Mar 18, 2026

Rollup merge of #153965 - Darksonn:kasan-minor-bugs, r=JonathanBrouwer

b3a5a31

Fix minor kasan bugs Fixes a few minor bugs discovered during rust-lang/rust#153049.

rustbot assigned fmease and unassigned chenyukang Mar 18, 2026

Darksonn mentioned this pull request Mar 22, 2026

Tracking issue for MCP 975: Add -Zsanitizer=kernel-hwaddress #154171

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fmease approved these changes Mar 24, 2026

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Auto merge of #153049 - Darksonn:kasan-sw-tags, r=<try>

6ca6a86

Add `-Zsanitize=kernel-hwaddress` try-job: test-various try-job: aarch64-gnu

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fmease added S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Mar 24, 2026

Darksonn added 2 commits March 24, 2026 17:39

Do not check for LEAK & KERNELHWADDRESS because they are incompatible

422906d

Document kernel-hwaddress in Unstable Book

4d86840

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jhpratt mentioned this pull request Mar 25, 2026

Rollup of 6 pull requests #154347

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Rollup of 5 pull requests #154353

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