| Message ID | 20230203194201.92015-1-ebiggers@kernel.org (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | randstruct: temporarily disable clang support | expand |
On Fri, Feb 03, 2023 at 11:42:01AM -0800, Eric Biggers wrote: > From: Eric Biggers <ebiggers@google.com> > > Randstruct with clang is currently unsafe to use in any clang release > that supports it, due to a clang bug that is causing miscompilations: > "-frandomize-layout-seed inconsistently randomizes all-function-pointers > structs" (https://github.com/llvm/llvm-project/issues/60349). Disable > it temporarily until the bug is fixed and the fix is released in a clang > version that can be checked for. > > Fixes: 035f7f87b729 ("randstruct: Enable Clang support") > Cc: stable@vger.kernel.org > Signed-off-by: Eric Biggers <ebiggers@google.com> > --- > security/Kconfig.hardening | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/security/Kconfig.hardening b/security/Kconfig.hardening > index 53baa95cb644..aad16187148c 100644 > --- a/security/Kconfig.hardening > +++ b/security/Kconfig.hardening > @@ -280,7 +280,8 @@ config ZERO_CALL_USED_REGS > endmenu > > config CC_HAS_RANDSTRUCT > - def_bool $(cc-option,-frandomize-layout-seed-file=/dev/null) > + # Temporarily disabled due to https://github.com/llvm/llvm-project/issues/60349 > + def_bool n > > choice > prompt "Randomize layout of sensitive kernel structures" > > base-commit: 7b753a909f426f2789d9db6f357c3d59180a9354 > -- > 2.39.1 This should be fixed with greater precision -- i.e. this is nearly fixed in Clang now, and is likely to be backported. So I think we'll need versioned checks here.
On Sat, Feb 4, 2023 at 11:06 AM Kees Cook <keescook@chromium.org> wrote: > > On Fri, Feb 03, 2023 at 11:42:01AM -0800, Eric Biggers wrote: > > From: Eric Biggers <ebiggers@google.com> > > > > Randstruct with clang is currently unsafe to use in any clang release > > that supports it, due to a clang bug that is causing miscompilations: > > "-frandomize-layout-seed inconsistently randomizes all-function-pointers > > structs" (https://github.com/llvm/llvm-project/issues/60349). Disable > > it temporarily until the bug is fixed and the fix is released in a clang > > version that can be checked for. > > > > Fixes: 035f7f87b729 ("randstruct: Enable Clang support") > > Cc: stable@vger.kernel.org > > Signed-off-by: Eric Biggers <ebiggers@google.com> > > --- > > security/Kconfig.hardening | 3 ++- > > 1 file changed, 2 insertions(+), 1 deletion(-) > > > > diff --git a/security/Kconfig.hardening b/security/Kconfig.hardening > > index 53baa95cb644..aad16187148c 100644 > > --- a/security/Kconfig.hardening > > +++ b/security/Kconfig.hardening > > @@ -280,7 +280,8 @@ config ZERO_CALL_USED_REGS > > endmenu > > > > config CC_HAS_RANDSTRUCT > > - def_bool $(cc-option,-frandomize-layout-seed-file=/dev/null) > > + # Temporarily disabled due to https://github.com/llvm/llvm-project/issues/60349 > > + def_bool n > > > > choice > > prompt "Randomize layout of sensitive kernel structures" > > > > base-commit: 7b753a909f426f2789d9db6f357c3d59180a9354 > > -- > > 2.39.1 > > This should be fixed with greater precision -- i.e. this is nearly fixed > in Clang now, and is likely to be backported. So I think we'll need > versioned checks here. > > -- > Kees Cook > Bill has requested cherry-pick the llvm-project fix into the release/16.x branch [1]. https://github.com/llvm/llvm-project-release-prs/pull/276 It may take one day to land. [1]: https://github.com/llvm/llvm-project/tree/release/16.x
On Mon, Feb 6, 2023 at 3:41 PM Fangrui Song <maskray@google.com> wrote: > > On Sat, Feb 4, 2023 at 11:06 AM Kees Cook <keescook@chromium.org> wrote: > > > > On Fri, Feb 03, 2023 at 11:42:01AM -0800, Eric Biggers wrote: > > > From: Eric Biggers <ebiggers@google.com> > > > > > > Randstruct with clang is currently unsafe to use in any clang release > > > that supports it, due to a clang bug that is causing miscompilations: > > > "-frandomize-layout-seed inconsistently randomizes all-function-pointers > > > structs" (https://github.com/llvm/llvm-project/issues/60349). Disable > > > it temporarily until the bug is fixed and the fix is released in a clang > > > version that can be checked for. > > > > > > Fixes: 035f7f87b729 ("randstruct: Enable Clang support") > > > Cc: stable@vger.kernel.org > > > Signed-off-by: Eric Biggers <ebiggers@google.com> > > > --- > > > security/Kconfig.hardening | 3 ++- > > > 1 file changed, 2 insertions(+), 1 deletion(-) > > > > > > diff --git a/security/Kconfig.hardening b/security/Kconfig.hardening > > > index 53baa95cb644..aad16187148c 100644 > > > --- a/security/Kconfig.hardening > > > +++ b/security/Kconfig.hardening > > > @@ -280,7 +280,8 @@ config ZERO_CALL_USED_REGS > > > endmenu > > > > > > config CC_HAS_RANDSTRUCT > > > - def_bool $(cc-option,-frandomize-layout-seed-file=/dev/null) > > > + # Temporarily disabled due to https://github.com/llvm/llvm-project/issues/60349 > > > + def_bool n > > > > > > choice > > > prompt "Randomize layout of sensitive kernel structures" > > > > > > base-commit: 7b753a909f426f2789d9db6f357c3d59180a9354 > > > -- > > > 2.39.1 > > > > This should be fixed with greater precision -- i.e. this is nearly fixed > > in Clang now, and is likely to be backported. So I think we'll need > > versioned checks here. > > > > -- > > Kees Cook > > > > Bill has requested cherry-pick the llvm-project fix into the > release/16.x branch [1]. > https://github.com/llvm/llvm-project-release-prs/pull/276 > It may take one day to land. > > [1]: https://github.com/llvm/llvm-project/tree/release/16.x > > -- > 宋方睿 > All landed; the version check should be for 16+. (And the link to the issue report would be nice to retain).
On Tue, Feb 07, 2023 at 10:01:21AM -0800, Nick Desaulniers wrote: > On Mon, Feb 6, 2023 at 3:41 PM Fangrui Song <maskray@google.com> wrote: > > > > On Sat, Feb 4, 2023 at 11:06 AM Kees Cook <keescook@chromium.org> wrote: > > > > > > On Fri, Feb 03, 2023 at 11:42:01AM -0800, Eric Biggers wrote: > > > > From: Eric Biggers <ebiggers@google.com> > > > > > > > > Randstruct with clang is currently unsafe to use in any clang release > > > > that supports it, due to a clang bug that is causing miscompilations: > > > > "-frandomize-layout-seed inconsistently randomizes all-function-pointers > > > > structs" (https://github.com/llvm/llvm-project/issues/60349). Disable > > > > it temporarily until the bug is fixed and the fix is released in a clang > > > > version that can be checked for. > > > > > > > > Fixes: 035f7f87b729 ("randstruct: Enable Clang support") > > > > Cc: stable@vger.kernel.org > > > > Signed-off-by: Eric Biggers <ebiggers@google.com> > > > > --- > > > > security/Kconfig.hardening | 3 ++- > > > > 1 file changed, 2 insertions(+), 1 deletion(-) > > > > > > > > diff --git a/security/Kconfig.hardening b/security/Kconfig.hardening > > > > index 53baa95cb644..aad16187148c 100644 > > > > --- a/security/Kconfig.hardening > > > > +++ b/security/Kconfig.hardening > > > > @@ -280,7 +280,8 @@ config ZERO_CALL_USED_REGS > > > > endmenu > > > > > > > > config CC_HAS_RANDSTRUCT > > > > - def_bool $(cc-option,-frandomize-layout-seed-file=/dev/null) > > > > + # Temporarily disabled due to https://github.com/llvm/llvm-project/issues/60349 > > > > + def_bool n > > > > > > > > choice > > > > prompt "Randomize layout of sensitive kernel structures" > > > > > > > > base-commit: 7b753a909f426f2789d9db6f357c3d59180a9354 > > > > -- > > > > 2.39.1 > > > > > > This should be fixed with greater precision -- i.e. this is nearly fixed > > > in Clang now, and is likely to be backported. So I think we'll need > > > versioned checks here. > > > > > > -- > > > Kees Cook > > > > > > > Bill has requested cherry-pick the llvm-project fix into the > > release/16.x branch [1]. > > https://github.com/llvm/llvm-project-release-prs/pull/276 > > It may take one day to land. > > > > [1]: https://github.com/llvm/llvm-project/tree/release/16.x > > > > -- > > 宋方睿 > > > > All landed; the version check should be for 16+. (And the link to the > issue report would be nice to retain). Thanks! Done in "[PATCH] randstruct: disable Clang 15 support" (https://lore.kernel.org/linux-hardening/20230208065133.220589-1-ebiggers@kernel.org). - Eric
diff --git a/security/Kconfig.hardening b/security/Kconfig.hardening index 53baa95cb644..aad16187148c 100644 --- a/security/Kconfig.hardening +++ b/security/Kconfig.hardening @@ -280,7 +280,8 @@ config ZERO_CALL_USED_REGS endmenu config CC_HAS_RANDSTRUCT - def_bool $(cc-option,-frandomize-layout-seed-file=/dev/null) + # Temporarily disabled due to https://github.com/llvm/llvm-project/issues/60349 + def_bool n choice prompt "Randomize layout of sensitive kernel structures"